concrete admixture

Abstract

Methods and compositions are provided that utilize one or more admixtures in combination with carbon dioxide in cement mixtures, such as cement mixtures containing aggregate (concrete), where the cement mixture includes, for example, a dosage of 0.01% to 5% carbon dioxide and one or more admixtures, based on the weight of the cement.

Description

[Technical Field]

[0001] Related Applications This application is related to the following co-pending patent applications, which are incorporated herein by reference: Application No. 15 / 650,524, filed July 14, 2017; Application No. 15 / 703,522, filed September 13, 2017; and Application No. 63 / 573,109, filed October 16, 2017. This application claims priority to U.S. Provisional Patent Application No. 63 / 394,554, filed August 2, 2022, which is incorporated herein by reference in its entirety. [Background technology]

[0002] Mineral admixtures have been used in concrete and mortar since at least Roman times. The Romans discovered that certain ingredients, such as milk, blood, and lard, as well as organic materials such as molasses, eggs, and rice paste, made cementitious mixtures more workable. While calcium chloride in concrete dates back to the first German patent in 1873, modern admixture technology began in North America in the 1930s with basic air-entraining agents, retarders, accelerators, and water-reducing admixtures. Recently, significant advances have been made in producing cement mixtures, such as concrete, that are easier to place and / or stronger using water-reducing admixtures and other types of admixtures. Furthermore, concrete mixtures with improved properties have also been produced by essentially using carbon dioxide as an admixture and adding small amounts of carbon dioxide to concrete mixtures. It is desirable to produce cement mixtures, such as concrete, using carbonation and one or more additional admixtures to produce cement mixtures, such as concrete, with improved properties.

[0003] Incorporation by Reference All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

[0004] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings. [Brief explanation of the drawings]

[0005] [Figure 1] 1 shows the power curves of cements with different carbon dioxide concentrations (Example 2). [Figure 2] 1 shows the energy curves of cements with different carbon dioxide concentrations, highlighting the energy at 16 hours (Example 2). [Figure 3] Energy at 16 hours versus CO2 input is shown (Example 2). [Figure 4] 1 shows the power curves for cement with different carbon dioxide concentrations using Exshaw GUL cement (Example 3). [Figure 5] 1 shows the energy curves of cements with different carbon dioxide concentrations using Exshaw GUL cement (Example 3). [Figure 6] 1 shows a plot of energy versus CO input at 20 hours using ExShaw GUL cement (Example 3). [Figure 7] 1 shows power curves for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture (PAANa, sodium polyacrylate), 0.08% dispersant (Example 4). [Figure 8] 1 shows the energy curves of cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture (PAANa, sodium polyacrylate), 0.08% dispersant (Example 4). [Figure 9]1 shows a plot of energy at 20 hours for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture (PAANa, sodium polyacrylate), 0.08% dispersant (Example 4). [Figure 10] 1 shows the power curves for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture (PAANa, sodium polyacrylate), 0.16% dispersant (Example 5). [Figure 11] 1 shows the energy curves of cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture (PAANa, sodium polyacrylate), 0.16% dispersant (Example 5). [Figure 12] 1 shows the energy plot at 20 hours for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture (PAANa, sodium polyacrylate), 0.16% dispersant (Example 5). [Figure 13] 1 shows power plots for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture, GCP Zyla 610, and 0.2% polycarboxylic ether (PCE) water reducer (Example 6). [Figure 14] 1 shows energy plots for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture, GCP Zyla 610, and 0.2% polycarboxylic ether (PCE) water reducer (Example 6). [Figure 15] 1 shows energy plots at 20 hours for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture, GCP Zyla 610, and 0.2% polycarboxylic ether (PCE) water reducer (Example 6). [Figure 16]1 shows power plots for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture, GCP Zyla 610, and 0.8% polycarboxylic ether (PCE) water reducer (Example 7). [Figure 17] 1 shows energy plots for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture, GCP Zyla 610, and 0.8% polycarboxylic ether (PCE) water reducer (Example 7). [Figure 18] 1 shows energy plots at 20 hours for cements with various carbon dioxide concentrations using ExShaw GUL cement and admixture, GCP Zyla 610, and 0.8% polycarboxylic ether (PCE) water reducer (Example 7). [Figure 19] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement (Example 8). [Figure 20] 1 shows a plot of the energy of cements with various carbon dioxide concentrations using National Lebec Type IL cement (Example 8). [Figure 21] FIG. 1 shows a plot of energy at 20 hours versus carbon dioxide input for cements with various carbon dioxide concentrations using National Lebec Type IL cement (Example 8). [Figure 22] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.385% Euclid Plastol 6400, a polycarboxylic acid ether (PCE) superplasticizer (Example 9). [Figure 23] 1 shows an energy plot of cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.385% Euclid Plastol 6400, a polycarboxylic acid ether (PCE) superplasticizer (Example 9). [Figure 24] FIG. 10 shows a plot of energy at 20 hours versus carbon dioxide input for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.385% Euclid Plastol 6400, a polycarboxylic acid ether (PCE) superplasticizer (Example 9). [Figure 25] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.385% Euclid Plastol 6400, a polycarboxylic ether (PCE) superplasticizer (Example 10). [Figure 26] 1 shows an energy plot of cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.385% Euclid Plastol 6400, a polycarboxylic acid ether (PCE) superplasticizer (Example 10). [Figure 27] FIG. 10 shows a plot of energy at 20 hours versus carbon dioxide input for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.385% Euclid Plastol 6400, a polycarboxylic acid ether (PCE) superplasticizer (Example 10). [Figure 28] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.37% Sika Plastocrete 161, a lignin polymer water reducer (Example 11). [Figure 29] 1 shows an energy plot of cement with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.37% Sika Plastocrete 161, a lignin polymer water reducer (Example 11). [Figure 30]1 shows a plot of energy at 20 hours for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.37% Sika Plastocrete 161, a lignin polymer water reducer (Example 11). [Figure 31] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.59% MasterPolyheed 997, a lignosulfonate triethanolamine-based medium-performance water reducer (Example 12). [Figure 32] 1 shows an energy plot of cement with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.59% MasterPolyheed 997, a lignosulfonate triethanolamine-based medium performance water reducer (Example 12). [Figure 33] FIG. 12 shows a plot of the energy at 20 hours for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.59% MasterPolyheed 997, a lignosulfonate triethanolamine-based medium performance water reducer (Example 12). [Figure 34] The effect on setting time of using an admixture alone and using carbon dioxide and an admixture together is shown (Example 13). [Figure 35] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.39% Euclid Eucon WR, a lignosulfate water reducer (Example 14). [Figure 36] 1 shows an energy plot of cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.39% Euclid Eucon WR, a lignosulfate water reducer (Example 14). [Figure 37]1 shows a plot of energy at 20 hours for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.39% Euclid Eucon WR, a lignosulfate water reducer (Example 14). [Figure 38] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.29% MasterGlenium 3030, a polycarboxylic acid ether (PCE) superplasticizer (Example 15). [Figure 39] 1 shows an energy plot of cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.29% MasterGlenium 3030, and a polycarboxylic acid ether (PCE) superplasticizer (Example 15). [Figure 40] FIG. 15 shows a plot of the energy at 20 hours for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.29% MasterGlenium 3030, and a polycarboxylic acid ether (PCE) superplasticizer (Example 15). [Figure 41] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.49% Sika Viscocrete 1000, a polycarboxylic acid ether (PCE) superplasticizer (Example 16). [Figure 42] 1 shows an energy plot of cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.49% Sika Viscocrete 1000, a polycarboxylic acid ether (PCE) superplasticizer (Example 16). [Figure 43]FIG. 16 shows the energy plot at 20 hours for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.49% Sika Viscocrete 1000, a polycarboxylic acid ether (PCE) superplasticizer (Example 16). [Figure 44] The effect on setting time of using an admixture alone and using carbon dioxide and an admixture together is shown (Example 17). [Figure 45] 1 shows a plot of cement power with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.26% GCP Zyla 640, a polycarboxylic acid ether (PCE) water reducer (Example 18). [Figure 46] 1 shows an energy plot of cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.26% GCP Zyla 640, a polycarboxylic acid ether (PCE) water reducer (Example 18). [Figure 47] FIG. 18 shows the energy plot at 20 hours for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixtures, 0.26% GCP Zyla 640, a polycarboxylic acid ether (PCE) water reducer (Example 18). [Figure 48] Figure 19 shows a plot of the power of cement with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.20% SikaControl Air 160, an air-entraining admixture (Example 19). [Figure 49] Figure 19 shows an energy plot of cement with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.20% SikaControl Air 160, an air-entraining admixture (Example 19). [Figure 50]Figure 19 shows energy plots at 20 hours for cements with various carbon dioxide concentrations using National Lebec Type IL cement and admixture, 0.20% SikaControl Air 160, an air-entraining admixture (Example 19). [Figure 51] 1 shows the compressive strength of concrete mixtures containing carbon dioxide and a medium-performance water reducer at 7 days (Example 20). [Figure 52] 1 shows the compressive strength of concrete mixtures containing carbon dioxide and a water reducer at 7 and 28 days (Example 20). [Figure 53] 1 shows a plot of the energy of cements with various water-to-cement ratios and carbon dioxide concentrations (Example 21). [Figure 54] Energy at 16 hours versus CO2 input is shown (Example 21). [Figure 55] The reaction rate versus water-to-cement ratio (w / c) is shown (Example 21). DETAILED DESCRIPTION OF THE INVENTION

[0006] Carbonation of wet cementitious mixtures (i.e., mixtures comprising cement, e.g., hydraulic cement such as Portland cement, and water, including mortar and concrete mixtures comprising cement, water, and aggregates) has been discovered to reduce the carbon footprint of structures made from the cementitious mixtures by reabsorbing carbon dioxide during the carbonation process and imparting higher strength to the hardened cementitious mixtures (e.g., higher strength at any or all of 1 day, 7 days, or 28 days) compared to uncarbonated mixtures. Because carbonated mixtures have higher strength, the carbon footprint of cementitious mixtures and structures made from such mixtures can be further reduced by using less cement and / or substituting more cement with supplemental cementitious materials (SCMs). See, e.g., PCT Publication No. WO2016082030, which is incorporated herein by reference in its entirety.

[0007] The compositions and methods described herein provide for the addition of carbon dioxide and at least one admixture to a wet cement mix. As known in the art, an admixture is any material or composition, other than hydraulic cement, aggregate, and water, used as a component of a cement mixture, such as a concrete or mortar, to enhance its properties or reduce its cost. The admixture may be added before, during, and / or after the addition of carbon dioxide, or in separate doses at a time different from the time of carbon dioxide addition. Furthermore, the admixture may be added before, during, and / or after contacting water with cement to produce a wet cement mix, or in separate doses at a time different from the time of contacting water with cement to produce a wet cement mix. In certain embodiments, one or more admixtures may be added with the admixture water, or before or after the admixture water is added. In general, the timing of adding the admixture is determined depending on the time when the carbon dioxide comes into contact with the wet cement mixture or the time when the wet cement mixture is produced by contacting water with cement, and in this specification, it is defined as being determined depending on the time when the carbon dioxide first comes into contact with the wet cement mixture or the time when water first comes into contact with the cement mixture.

[0008] In certain embodiments, the methods and compositions of the present invention utilize the addition of multiple different admixtures in combination with carbonation of a wet cement mixture. Two or more admixtures, e.g., three, four, five, six, seven, eight, or more admixtures, may be mixed in a single "cocktail," e.g., dissolved or dispersed in an aqueous or other suitable medium. The cocktail may be used alone or in combination with additional admixtures. Typically, admixtures are used in wet-mix processes, such as ready-mix or precast processes, and the compositions and methods herein are described with respect to ready-mix processes, although it will be understood that other types of processes involving wet cement mixtures, possibly with modifications, are also encompassed herein, as will be apparent to those skilled in the art.

[0009] Without wishing to be bound by theory, it is believed that carbonation of the wet cement mix produces nanoparticles of calcium carbonate that are uniformly dispersed throughout the wet cement mix and act both physically and chemically to promote hydration and other reactions as the wet cement mix reacts. Thus, in this environment, the admixture: Ca in solution 2+ generating or stabilizing Preventing coarsening or agglomeration of carbonate reaction products; controlling the size or shape of the carbonate reaction product; Promoting homogeneous nucleation of CaCO3 (e.g., in solution rather than on a surface); affecting the interaction of the CO with sulfates, ferrites, alkalis, magnesium salts, and / or aluminates (which may either inhibit or promote the interaction); affecting the action of sulfates, ferrites, alkalis, magnesium salts, and / or aluminates (which may either inhibit or promote their activity); Counteracting the acceleration caused by CO2 (e.g., using retarders) To offset the workability loss associated with carbonation (e.g., by using plasticizers), Controlling, modifying or otherwise influencing the properties of the carbonate reaction products formed; and This may be useful in a variety of ways, including, but not limited to, controlling, modifying, or otherwise influencing the development of hydration products that occur in the carbonate products (see, e.g., Moghaddam et al., J. Materials Chem. A, DOI 10 1039 / c6ta09389b, 2016).

[0010] The methods and compositions of the present invention involve adding carbon dioxide to a wet cement mixture while mixing the mixture. In a ready-mix process, typically, a majority of the admixture water, e.g., 60% to 70% of the final volume, is first added to a mixer (e.g., the drum of a ready-mix truck or a central mixer). Next, cement is added to the mixer and mixed with the water. Aggregate, if used, is also added throughout the mixing process. Because the amount of aggregate typically far exceeds the amounts of cement and water, it is important to add the aggregate over a sufficient period of time. Carbon dioxide can be added any time after the cement is initially contacted with water. The timing of carbon dioxide addition can vary depending on the type of admixture(s) added to the cement mixture (e.g., as part of the admixture water) before adding the carbon dioxide, as it may be important in certain cases for the admixture(s) to have reacted to a certain point in time to ensure optimal effectiveness in combination with carbonation. The carbon dioxide may be in any suitable form, e.g., solid, gaseous, liquid, and / or supercritical carbon dioxide. In certain embodiments, carbon dioxide is added as a mixture of solid and gaseous carbon dioxide formed from liquid carbon dioxide. The carbon dioxide dosage can be any suitable dosage, for example, as described in PCT Publication No. WO2016082030. In certain embodiments, the carbon dioxide dosage is 0.001% to 10.0% by weight (bwc) of cement, e.g., 0.001% to 5.0% bwc, or 0.001% to 2.0% bwc, or 0.001% to 1.0% bwc, or 0.005% to 1.0% bwc, or 0.005% to 0.5% bwc. The use of certain admixtures may allow for larger dosages than would normally be possible, for example, by delaying premature setting induced by the addition of large amounts of carbon dioxide in mixtures with certain types of cement. In some applications, for example, in 3D printing with cement mixtures such as concrete, combining a suitable dosage of carbon dioxide with an admixture that can control the hardening rate can be particularly useful.For example, a carbonated cement mixture, e.g., a hydraulic cement mixture for use in a wet casting process, may have workability / flow properties that are optimized by the addition of an admixture. As another example, a carbonated mixture may have strength properties, e.g., compressive strength at one or more time points, that are optimized by the addition of an admixture. In some cases, the mix design may already call for the use of an admixture, and the effect of that admixture on the properties of the mixture may change with carbonation, so that the timing of the admixture addition needs to be adjusted in response to the addition of carbon dioxide, or other manipulation is required. Admixtures may also be used to adjust one or more aspects of the carbonation itself, for example, to increase the rate of carbon dioxide uptake.

[0011] In certain cases, carbonation of a cement mixture, e.g., a hydraulic cement mixture, can affect the fluidity of a cement mixture, e.g., a hydraulic cement mixture, i.e., a concrete mixture, used in a wet casting process, such as a mixture delivered to a job site in a ready-mix truck. Thus, in certain embodiments, when producing a carbonated mixture (e.g., one used in a ready-mix truck), one or more admixtures are added before, during, or after carbonation, or when combining them, to adjust the fluidity of the carbonated mixture to within a certain percentage of the fluidity of the same mixture without carbonation, or within a predetermined specific fluidity range. By adding additional components such as carbon dioxide, mixture components (e.g., a concrete mixture), and / or one or more admixtures, the fluidity of the final mixture can be adjusted to within 50%, 40%, 30%, 20%, 10%, 8%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.1% of the fluidity achieved without the addition of carbon dioxide, or within a predetermined specific fluidity range. In certain embodiments, the addition of carbon dioxide, mixture components, and / or one or more admixtures may adjust the fluidity of the final mixture to within 20% of the fluidity that would be achieved without the addition of carbon dioxide, or to within 20% of a preset desired fluidity. In certain embodiments, the addition of carbon dioxide, mixture components, and / or one or more admixtures may adjust the fluidity of the final mixture to within 10% of the fluidity that would be achieved without the addition of carbon dioxide, or to within 10% of a preset desired fluidity. In certain embodiments, the addition of carbon dioxide, mixture components, and / or one or more admixtures may adjust the fluidity of the final mixture to within 5% of the fluidity that would be achieved without the addition of carbon dioxide, or to within 5% of a preset desired fluidity. In certain embodiments, the addition of carbon dioxide, mixture components, and / or one or more admixtures may adjust the fluidity of the final mixture to within 2% of the fluidity that would be achieved without the addition of carbon dioxide, or to within 2% of a preset desired fluidity. Any suitable measurement method for determining fluidity may be used, such as the well-known slump test.Any suitable admixture described herein may be used.

[0012] In certain embodiments, admixtures are added to a carbonated mixture before, during, or after carbonation, or a combination thereof, under conditions such that the strength of the carbonated mixture, e.g., compressive strength at 1 day, 7 days, 28 days, and / or 56 days, is within a desired percentage of the strength of the same mixture without carbonation, or within a predetermined strength, e.g., within 50%, 40%, 30%, 20%, 15%, 12%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.1%. In certain embodiments, the addition of carbon dioxide, mixture components, and / or one or more admixtures can adjust the strength of the final mixture at a particular time to within 20% of the strength achieved without the addition of carbon dioxide, or to within 20% of a predetermined desired strength. In certain embodiments, the addition of carbon dioxide, mixture components, and / or one or more admixtures may adjust the strength of the final mixture at a specific time to within 10% of the strength that would be achieved without the addition of carbon dioxide, or within 10% of a preset desired strength. In certain embodiments, the addition of carbon dioxide, mixture components, and / or one or more admixtures may adjust the strength of the final mixture at a specific time to within 5% of the strength that would be achieved without the addition of carbon dioxide, or within 5% of a preset desired strength. In certain embodiments, the addition of carbon dioxide, mixture components, and / or one or more admixtures may adjust the strength of the final mixture at a specific time to within 2% of the strength that would be achieved without the addition of carbon dioxide, or within 2% of a preset desired strength. In certain embodiments, the strength is compressive strength. Any suitable strength testing method, such as flexural strength or compressive strength, may be performed with or without carbonation, as long as the same test is performed, and such tests are well known in the art.

[0013] In certain embodiments, the use of both admixtures and carbonation results in higher compressive strength than the use of admixtures alone, carbonation alone, or cement alone. Different cements have been found to exhibit different properties upon carbonation and to respond differently to particular admixtures. Accordingly, the present invention includes compositions and methods for improving the compressive strength of carbonated cement mixtures, such as concrete mixtures, at one or more time points by using one or more admixtures, where the compressive strength of the carbonated cement mixture with the admixture is greater than the compressive strength of the carbonated cement mixture alone.

[0014] In certain embodiments, the admixture is added to the carbonated mixture before, during, or after carbonation, or a combination thereof, such that the strength of the mixture, e.g., compressive strength at 1 day, 7 days, 28 days, and / or 56 days, is at least 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, 17%, 20%, 25%, 30%, or 40% or more, and / or 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, 17%, 20%, 25%, 30%, 40%, 60%, or 80% or less, preferably at least 5% or more, more preferably at least 10% or more, and even more preferably at least 15% or more, than the strength of the same carbonated mixture without the admixture. In some cases, cementitious mixtures, such as concrete mixtures, in which certain cements are used do not exhibit the desired strength increase through carbonation alone, generally due to the different reactivity of various types of cement to carbonation. Therefore, the addition of one or more admixtures can help achieve the desired strength improvement that cannot be achieved through carbonation alone (at the dosages used). In such cases, carbonation can be added at any suitable level, such as at least 0.005%, 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.7%, or 2.0% by weight cement (bwc), and / or 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.7%, or 2.0% by weight cement (bwc). It can be practiced at dosages of 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.7%, 2.0%, or 2.5% or less, preferably in the range of 0.005% to 2.5%, more preferably 0.01% to 1.5%, and even more preferably 0.01% to 1.0%. The admixture(s) can be any suitable admixture, such as, for example, the admixtures described herein, used at any suitable dosage level described herein.In certain embodiments, the admixture comprises a polymer of a polycarboxylate or polycarboxylic acid derivative, such as a polycarboxylic acid ether, as described herein. The admixture can be provided in any suitable composition, and in certain embodiments, some or all of the admixture is provided as a mixture with water, with at least some of the water being wash water from a concrete process, e.g., carbonated wash water, or treated wash water, e.g., wash water that has been treated to remove particulate matter, e.g., clarified wash water, as described in more detail elsewhere herein.

[0015] The reactivity of a concrete mixture may be indicative of its compressive strength. Reactivity can be measured using any suitable technique, e.g., calorimetry. See also the Examples. Generally, the energy generated by a cementitious mixture as it sets may be indicative of the compressive strength of the cementitious mixture after it has set and hardened; e.g., a higher rate of energy increase may indicate a higher compressive strength achieved after it has set and hardened. Thus, in certain embodiments, a method of increasing the reactivity of a cementitious mixture, such as a concrete mixture, as measured by calorimetry, is provided, the method comprising carbonating the cementitious mixture and adding one or more admixtures to the cementitious mixture, wherein the increased reactivity is indicated by an increased rate of energy production as measured by calorimetry compared to the same mixture without carbonation, the admixture, or both.

[0016] Other properties such as water absorption, shrinkage, chloride permeability, etc. may also be tested and adjusted in the same manner and at the same rates as for flowability and / or shrinkage.

[0017] The effects of carbonation and admixtures on carbonated cementitious mixtures, such as hydraulic cement mixtures, have been observed to vary significantly from mixture to mixture. In some cases, carbonation improves the properties of the mixture, eliminating the need for admixtures, particularly in dry-cast situations where flowability is not an issue. In other cases, particularly in wet-cast situations where flowability is an issue, one or more admixtures may be needed to restore one or more properties of the mixture. Whether and / or how much admixture to add to a particular batch can be determined by pre-testing the mixture to identify the properties of the carbonated mixture and the effect of a given admixture. In some cases, the addition of admixtures and / or the amount of admixture to add can be predicted based on past testing, the properties of the cement used in the mixture, or theoretical considerations.

[0018] Timing of admixture addition can be important. Typically, at least two timing aspects must be considered. First, the timing of admixture addition relative to the start of mixing of a cement mixture can be important because some admixtures work best when added earlier than the start of mixing, while others work best when added after chemical and other reactions have progressed. Second, the timing of admixture addition relative to the addition of carbon dioxide can be important because the carbonation reaction begins very quickly after the addition of carbon dioxide; for example, calcium carbonate particles form quickly, and the mixture of metastable polymorphs may change over time as the reaction progresses. In some cases, the admixture is used in one or more doses, each dose being added at a different time relative to the start of mixing and the addition of carbon dioxide. In some cases, the carbon dioxide is used in one or more doses, each dose being added at a different time relative to the start of mixing and the addition of the admixture. In some cases, the admixture is used in multiple doses, and the carbon dioxide is used in multiple doses.

[0019] When multiple admixtures are used, all of the admixtures may be added at once, or their addition may be split into two or more additions. In some cases, the admixture may be co-ground or otherwise mixed with the cement mixture, e.g., alkanolamines or certain deaerators, in which case the admixture is present at the start of mixing the cement and water. In other cases, the admixture may be included in the initial mixwater, in which case the admixture is also present at the start of mixing the cement and water. In both of these cases, the admixture is added to the cement mixture before the addition of carbon dioxide, since the carbon dioxide reaction requires the presence of both water and cement. In some cases, for example, when carbonated water is used as the carbon dioxide source, the admixture may be added in water but before contact with the cement. Alternatively, the admixture may be added at any time after the start of cement mixing and before the cement mixture is poured. For example, many admixtures are prepared as standard aqueous mixtures and added as the concrete is mixed until the desired amount of admixture corresponding to the desired amount of admixture is added to the concrete mixture. This can be done before, during, and / or after the addition of carbon dioxide. In some cases, the admixture is added on-site, e.g., after testing the slump of the concrete, additional admixture may be added to adjust the slump.

[0020] Therefore, the present invention includes any of the following configurations: A1 is a first admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A2 is a second admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A3 is a third admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A4 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A5 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A6 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A7 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A8 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A9 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A1 ...2 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A3 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than eight admixtures), A4 is a fourth admixture (or a mixture of two, three, four, five, six, seven, eight, or more than A1, A2, A3, A4 may be similar or different, or any of A1, A2, A3, A4 may be similar or different (e.g., a particular admixture may be present in both A1 and A2, while a second admixture may be present only in A1 or only in A2; it will be understood that the foregoing is merely exemplary and that numerous combinations and permutations are possible).

[0021] 1) A1 is added as part of the mix water or co-ground or added to dry cement prior to adding the cement, contacting the cement with the mix water to initiate mixing of the cement and mix water, optionally adding admixtures A2, A3, and / or A4 to the mixed cement mixture after mixing has begun, and carbon dioxide is added during mixing of the wet cement mixture, which may begin within 10, 20, 30, 40, 50, or 60 seconds of starting mixing the cement mixture, or within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 60, 90, or 120 minutes of starting mixing the cement mixture, and / or within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 60, 90, or 120 minutes before final pouring of the concrete (e.g., in-situ carbon dioxide addition). In some cases, it may be desirable to allow the reaction of the cementitious / admixture to proceed for a minimum amount of time before adding the carbon dioxide, and therefore, in this case, the addition of carbon dioxide may not begin more than 1, 2, 5, 10, 20, 30, 40, 50, or 60 seconds after the start of mixing of the cementitious mixture (including at least A1), or more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 60, 90, or 120 minutes after the start of mixing of the cementitious mixture (including A1), and / or no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 60, 90, or 120 minutes before the final pour of the concrete (e.g., in-situ carbon dioxide addition). In some cases, the addition of carbon dioxide may be split into two or more doses, with each dose being timed differently depending on the start of mixing (and thus contact with the contact product of A1 and the cement mixture). When A2, A3, and / or A4 are added after the start of mixing, the carbon dioxide addition occurs before or after and / or simultaneously with the addition of the additional admixtures, e.g., before and / or during the addition of A2, during and / or after the addition of A2, before and / or during the addition of A3, during and / or after the addition of A3, before and / or during the addition of A4, during and / or after the addition of A4.If carbon dioxide addition is started before the addition of A2, A3, and / or A4, it may start at least 1, 2, 5, 10, 20, 30, 40, 50, or 60 seconds before the addition of A2, A3, and / or A4, or at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes before the addition of A2, A3, or A4. In all of these cases, the carbon dioxide supply may continue during and / or after the addition of the admixture, or the carbon dioxide supply may be stopped before the addition of the admixture. The carbon dioxide addition may start during the addition of A2, A3, and / or A4 and be stopped before the addition of A1, A2, and / or A4 is complete, or be continued after the addition is complete. When carbon dioxide addition is initiated after the addition of A2, A3, and / or A4, the carbon dioxide addition may be initiated at least 1, 2, 5, 10, 20, 30, 40, 50, or 60 seconds after the addition of A2, A3, and / or A4, or at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes after the addition of A2, A3, or A4. In certain cases, the carbon dioxide supply is divided into two or more doses. When A2, A3, and / or A4 are added to the cement mixture, the timing of the supply of A2, A3, and / or A4 relative to each dose of carbon dioxide can be any suitable timing. For example, A2 can be added after two doses of carbon dioxide, followed by A3 after two doses of carbon dioxide. The latter is for illustrative purposes only; any suitable dosing scheme for carbon dioxide, and optionally A2, A3, and / or A4, can be used.Additionally, the timing of addition of A2, A3, and / or A4 relative to the start of mixing (i.e., initial contact of cement with water) can also be important, so addition of any or all of A2, A3, and / or A4 should be at least 1, 2, 5, 10, 20, 30, 40, 50, or 60 seconds after the start of mixing, or at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, or 24 seconds after the start of mixing. The addition of A2, A3, or A4 may be initiated in situ, and / or at not more than 30 minutes, and / or not more than 2, 5, 10, 20, 30, 40, 50, or 60 seconds after mixing has begun, or not more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, or 30 minutes after mixing has begun, and optionally one or more of A2, A3, or A4 may be added in situ, and one or more of A2, A3, or A4 may be added several hours after mixing has begun.

[0022] 2) Initiate mixing of the cement and admixture water by contacting the cement with the admixture water. A1 and optionally additional admixtures A2, A3, and / or A4 are added to the mixed cement mixture after mixing begins, and carbon dioxide is added to the mixed wet cement mixture. The length of time between the start of mixing and the addition of A1 depends on the composition of A1 and the desired effect. For example, the addition of A1 can begin within 1, 2, 5, 10, 20, 30, 40, 50, or 60 seconds of the start of mixing the cement mixture, or within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, or 30 minutes of the start of mixing the cement mixture, and / or within 2, 5, 10, 20, 30, 40, 50, or 60 seconds of the start of mixing the cement mixture, or within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, or 30 minutes of the start of mixing the cement mixture. In some cases, A1 is added more than 10 minutes after the start of mixing the cement mixture. The timing of adding carbon dioxide to the mixture relative to the addition of A1 not only depends on the composition of A1, but also on the interaction of carbonation on the effect of A1, and vice versa. Thus, carbon dioxide can be added before, during, or after the addition of A1, or any combination thereof. Furthermore, the carbon dioxide charge can be split into two or more charges, with each charge added at a different time relative to the addition of A1. For example, a first charge of carbon dioxide can be added before the addition of A1, and a second charge of carbon dioxide can be added after the addition of A1. The same considerations apply to A2, A3, and / or A4, if added to the mixture. The addition of carbon dioxide can begin within 10, 20, 30, 40, 50, or 60 seconds of the start of mixing the cement mixture, or within 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes of the start of mixing the cement mixture. In some cases, the carbon dioxide is added more than 10 minutes after the start of mixing the cement mixture.In some cases, it is desirable to allow the reaction in the cement / admixture to proceed for a minimum time before adding the carbon dioxide, so in this case the addition of carbon dioxide may not be initiated for at least 10, 20, 30, 40, 50, or 60 seconds after the addition of A1 to the cement mixture, or for at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes after the addition of A1 to the cement mixture. In some cases, it is desirable to allow the carbonation reaction in the cement mixture to proceed for a minimum time before adding A1, so in this case the addition of A1 may not be initiated for at least 1, 5, 10, 20, 30, 40, 50, or 60 seconds after the addition of carbon dioxide to the cement mixture, or for at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes after the addition of carbon dioxide to the cement mixture. In some cases, the addition of carbon dioxide overlaps with the addition of A1. Additionally, the carbon dioxide charge can be split into two or more charges, each added at a different time relative to the addition of A1. For example, a first charge of carbon dioxide can be added before the addition of A1, and a second charge of carbon dioxide can be added after the addition of A1. If A2, A3, and / or A4 are added after mixing has begun, the carbon dioxide can be added before, after, and / or simultaneously with the addition of the additional admixtures, e.g., before and / or during the addition of A2, during and / or after the addition of A2, before and / or during the addition of A3, during and / or after the addition of A3, before and / or during the addition of A4, during and / or after the addition of A4. If the carbon dioxide addition is started before the addition of A2, A3, and / or A4, the carbon dioxide addition may be started at least 1, 2, 5, 10, 20, 30, 40, 50, or 60 seconds before the addition of A2, A3, and / or A4, or at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes before the addition of A2, A3, or A4. In all of these cases, the carbon dioxide supply may be continued during and / or after the addition of the admixture, or the carbon dioxide supply may be stopped before the addition of the admixture.The addition of carbon dioxide may begin during the addition of A2, A3, and / or A4, be stopped before the addition of A1, A2, and / or A4 is complete, or be continued after the addition is complete. If the addition of carbon dioxide begins after the addition of A2, A3, and / or A4, the addition of carbon dioxide may begin at least 1, 2, 5, 10, 20, 30, 40, 50, or 60 seconds after the addition of A2, A3, and / or A4, or at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes after the addition of A2, A3, or A4. In certain cases, the carbon dioxide supply is split into two or more doses. When A2, A3, and / or A4 are added to the cement mixture, the timing of the supply of A2, A3, and / or A4 relative to each dose of carbon dioxide may be any suitable timing. For example, adding A2 after two carbon dioxide doses, followed by adding A3 after two carbon dioxide doses, etc. The latter is for illustrative purposes only; any suitable dosing scheme for carbon dioxide, and optionally A2, A3, and / or A4, may be used. In some cases, split doses of A1 are added at different times relative to the start of mixing and relative to the addition of carbon dioxide. In certain cases, split doses of both A1 and carbon dioxide are added. Furthermore, the timing of the addition of A2, A3, and / or A4 relative to the start of mixing (i.e., initial contact of cement with water) may also be important; thus, addition of any or all of A2, A3, and / or A4 may be at least 1, 2, 5, 10, 20, 30, 40, 50, or 60 seconds after the start of mixing, or at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, or 35 seconds after the start of mixing. The addition of A2, A3, or A4 may be initiated in situ, and / or at not more than 30 minutes, and / or not more than 2, 5, 10, 20, 30, 40, 50, or 60 seconds after mixing has begun, or not more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, or 30 minutes after mixing has begun, and optionally one or more of A2, A3, or A4 may be added in situ, and one or more of A2, A3, or A4 may be added several hours after mixing has begun.

[0023] Compositions containing admixtures and / or systems and methods for preparing and / or using compositions containing admixtures In certain embodiments, a composition is provided that includes one or more admixtures. The composition may include any suitable admixture, such as an admixture disclosed herein. The composition may include any suitable number of admixtures disclosed herein. In certain embodiments, the composition includes one or more admixtures and water, e.g., an admixture solution. In certain embodiments, the admixture includes a dispersing admixture, such as a water-reducing agent, e.g., a superplasticizer, e.g., PCE. In certain embodiments, the admixture includes a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic acid ether; a lignin, such as a lignin polymer, lignosulfate, lignosulfonate, triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof. In certain embodiments, the admixture includes a polycarboxylate or a polycarboxylic acid derivative, e.g., a polycarboxylic acid ether. In certain embodiments, the polycarboxylate or polycarboxylic acid derivative is present in an amount of 0.1% to 1% bwc, preferably 0.2% to 1% bwc, and more preferably 0.2% to 0.8% bwc. In certain embodiments, the admixture includes lignin or a lignin derivative, such as a lignosulfate, a lignosulfonate, or a combination thereof. In certain embodiments, the lignin or lignin derivative is present in an amount present at a concentration of 0.2% to 8% bwc, preferably 0.2% to 6% bwc, and more preferably 0.3% to 0.5% bwc. In certain embodiments, the admixture includes a polyacrylate or polyacrylic acid derivative. In certain embodiments, the polyacrylate or polyacrylic acid derivative is present in an amount of 0.02% to 0.3% bwc, preferably 0.04% to 0.2% bwc, and even more preferably 0.06% to 0.2% bwc. Any suitable water source may be used, such as water typically used in the production of concrete. In certain embodiments, the water includes potable water. In certain embodiments, the water includes industrial water. Additionally or alternatively, the water includes concrete reclaim water, such as wash water. The water may include a mixture of potable water and concrete reclaim water, in which case any suitable ratio of potable water to concrete reclaim water may be used.In certain embodiments, concrete reclaimed water, e.g., wash water, contains solids. In certain embodiments, the solids are not removed before combining with one or more admixtures. In certain embodiments, at least a portion of the solids are removed before combining with one or more admixtures, e.g., to produce clarified wash water. In certain embodiments, concrete reclaimed water, e.g., wash water, is carbonated. In certain embodiments, one or more admixtures, e.g., a polymer admixture such as a polycarbonate or polycarbonate derivative admixture, are mixed with wash water obtained from a concrete process, e.g., that has been carbonated and, optionally, filtered or otherwise treated to remove solids, e.g., clarified wash water. In certain embodiments, the composition can be combined with cement and / or aggregate to form a cement product as disclosed herein. Carbonation of wash water is further described in PCT Publication No. WO 2021 / 071980.

[0024] In certain embodiments, provided herein are methods for producing admixtures. In certain embodiments, the methods include adding one or more admixtures to water, for example, to create an admixture solution. The methods may include adding any suitable admixture, such as an admixture disclosed herein, to water. The methods may include adding any suitable number of admixtures disclosed herein to water. In certain embodiments, the methods include adding a dispersing admixture, such as a water-reducing agent, for example, a superplasticizer, e.g., PCE. In certain embodiments, the admixture includes a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic acid ether; a lignin, such as a lignin polymer, lignosulfate, lignosulfonate triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof. In certain embodiments, the admixture includes a polycarboxylate or a polycarboxylic acid derivative, for example, a polycarboxylic acid ether. In certain embodiments, the polycarboxylate or polycarboxylic acid derivative is present in an amount of 0.1% to 1% bwc, preferably 0.2% to 1% bwc, and more preferably 0.2% to 0.8% bwc. In certain embodiments, the admixture includes lignin or a lignin derivative, such as a lignosulfate, a lignosulfonate, or a combination thereof. In certain embodiments, the lignin or lignin derivative is present in an amount present at a concentration of 0.2% to 8% bwc, preferably 0.2% to 6% bwc, and more preferably 0.3% to 0.5% bwc. In certain embodiments, the admixture includes a polyacrylate or polyacrylic acid derivative. In certain embodiments, the polyacrylate or polyacrylic acid derivative is present in an amount of 0.02% to 0.3% bwc, preferably 0.04% to 0.2% bwc, and even more preferably 0.06% to 0.2% bwc. In certain embodiments, the water includes potable water. Additionally or alternatively, the water includes concrete reclaimed water, such as wash water. The water may include a mixture of potable water and concrete reclaimed water. In certain embodiments, the method includes a mixture of potable water and concrete reclaimed water prior to adding the admixture.In this case, any suitable ratio of potable water to concrete reuse water may be used. In certain embodiments, the concrete reuse water includes solids. In certain embodiments, the method further includes removing at least a portion of the solids from the water before adding one or more admixtures to the water, e.g., to produce purified wash water. In certain embodiments, the method further includes carbonating the water. In certain embodiments, the method further includes combining the admixture solution with cement and / or aggregate to form a cement product disclosed herein.

[0025] In certain embodiments, the present disclosure provides an apparatus for preparing an admixture, such as an admixture solution. In certain embodiments, the apparatus is configured to prepare an admixture solution disclosed herein. In certain embodiments, the apparatus includes a water source, one or more admixture sources (disclosed herein), and a container, where the water source and the one or more admixture sources are operably connected to the container. In certain embodiments, the apparatus is configured to combine water from the water source and one or more admixtures from the one or more admixture sources in the container. The apparatus may further include a mixer configured to combine the admixture and water. In certain embodiments, the apparatus further includes a gas source. Any suitable gas, such as liquid nitrogen or carbon dioxide, preferably carbon dioxide, can be used. In certain embodiments, the device further includes a first conduit operably connected to the container at a proximal end, through which the admixture solution flows and exits at a distal end, and a second conduit positioned inside the first conduit, operably connected to a gas source and configured to allow gas to flow into and out of the admixture solution within the first conduit. In certain embodiments, the distal end of the first conduit is operably connected to the container, such that the admixture solution can be circulated through the first conduit into the container at a desired time and / or until the admixture solution reaches a desired level of carbonation. In certain embodiments, the second conduit is perforated. In certain embodiments, the first conduit has a diameter of 0.5 to 5 inches, and the second conduit has a diameter of 0.3 to 3 inches. In certain embodiments, the apparatus further includes a control system that senses a property of the admixture solution and transmits information about the property to a controller that processes the information from the sensors. Any suitable number of sensors may be used, for example, at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 sensors and / or up to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 sensors, for example, 1 to 20 sensors.The sensors can monitor any suitable characteristic of the admixture solution, such as: (1) pH of the admixture solution, (2) rate of carbon dioxide supply to the admixture solution, (3) total volume of the admixture solution in the container, (4) temperature of the admixture solution, (5) specific gravity of the admixture solution, (6) concentration of one or more ions in the admixture solution, (7) age of the admixture solution, (8) circulation rate of the admixture solution, (9) timing of circulation of the admixture solution, (10) appearance of air bubbles on the surface of the admixture solution, (11) carbon dioxide concentration in the air above the admixture solution, (12) electrical conductivity of the admixture solution, (13) optical properties of the admixture solution, and (14) amount of admixture added to the admixture solution. In certain embodiments, the control system further includes an actuator that receives a signal from the controller based at least in part on the processed information from the sensors. In certain embodiments, the actuator includes a valve. In certain embodiments, the controller includes at least two sensors, and the sensors are configured to monitor at least two characteristics. In certain embodiments, the controller includes at least three sensors, and the sensors are configured to monitor at least three characteristics. In certain embodiments, the controller includes at least four sensors, and a second sensor is configured to monitor at least four characteristics. In certain embodiments, the controller includes at least five sensors, and a second sensor is configured to monitor at least five characteristics. The characteristics may be the same or different, for example, the specific gravity and amount of admixture added to the water, and / or temperature. A second example may include specific gravity at one or more locations within the container. In certain embodiments, the water source includes potable water. In certain embodiments, the water source includes concrete reclamation water, such as wash water. In certain embodiments, the water source includes multiple water sources, each different from the others, for example, a first water source including potable water and a second water source including concrete reclamation water, and the device is configured to supply a mixture of potable water and concrete reclamation water to the container. The apparatus can be configured to provide potable water and concrete reclaimed water in any ratio suitable for the intended admixture. In certain embodiments, the water source comprises a reclaimer. In other embodiments, the vessel is a reclaimer.In certain embodiments, the apparatus is further configured to remove at least a portion of the solids from the concrete reclaimed water before or after combination with the one or more admixtures.

[0026] Admixture [Table 1]

[0027] [Table 2]

[0028] In certain embodiments, the present disclosure provides admixtures. Any suitable admixture may be used. In certain embodiments, the admixture comprises a polymer. In certain embodiments, the admixture comprises a linear polymer. In certain embodiments, the admixture comprises a branched polymer, e.g., a comb polymer. In certain embodiments, the admixture comprises a mixture of linear and branched polymers. The ratio of linear to branched polymer in the admixture composition, admixture solution, or cement mixture can be any suitable ratio, for example, at least 1:1, 1:2, 1:5, 1:10, or 1:20, and / or up to 1:2, 1:5, 1:10, 1:20, or 1:40. Any suitable monomer can be used to form the admixture. In certain embodiments, the admixture comprises a polymer backbone comprising acrylic acid, methacrylic acid, maleic acid, vinyl, allyl, Jeffamine, or a combination thereof. In certain embodiments, the polymer comprises one or more side chains, such as polyethylene oxide. Any suitable chemical reaction, e.g., ester-, ether-, and / or amide-based linkages, can be used to attach one or more side chains to the polymer. In certain embodiments, the polymer includes one or more modifications including hydroxyl and / or carboxylic acid groups. In preferred embodiments, the admixture is anionic, e.g., includes a net negative charge. The molecular weight (MW) of the polymer can be any suitable molecular weight, e.g., at least 1, 5, 10, 100, 500, and / or up to 5, 10, 100, 500, or 1,000 kDa, e.g., between 1 and 1,000 kDa. Exemplary polymers include polyacrylates and polyacrylic acid derivatives, and polycarboxylates and polycarboxylic acid derivatives, e.g., polycarboxylate ethers.

[0029] This section summarizes some useful admixtures for use in the methods and compositions herein. For an additional listing, see Report on Chemical Admixtures for Concrete, Reported by ACI Committee 212, American Concrete Institute, ACI 212.3R-16, ISBN 978-1-942727-80-4, which is incorporated herein by reference in its entirety.

[0030] Admixtures useful in the methods and compositions herein include:

[0031] Accelerator: Accelerator accelerates setting and / or early strength development by increasing the rate of hydration. Generally, accelerating admixtures for concrete must meet the requirements of Type C (accelerating admixtures) or Type E (water-reducing and accelerating admixtures) of ASTM C494 / C494M. Examples include inorganic salts such as chlorides, bromides, fluorides, carbonates, thiocyanates, nitrites, nitrates, thiosulfates, silicates, aluminates, and alkali hydroxides. Of particular interest are calcium-containing compounds such as CaO, Ca(NO2)2, Ca(OH)2, calcium stearate, or CaCl2, and magnesium-containing compounds such as magnesium hydroxide, magnesium oxide, magnesium chloride, or magnesium nitrate. Without being bound by theory, it is believed that in carbonated cements, the added calcium or magnesium compounds provide free calcium or magnesium to react with carbon dioxide, providing a reservoir for carbon dioxide absorption without damaging the calcium in the cement mixture, or providing a carbonation site different from the calcium in the cement, or both, thereby preserving early strength development. Furthermore, anions, such as nitrates from calcium-containing admixtures, can affect the particle structure of CSH. Other set accelerators include, but are not limited to, alkali metal, alkaline earth metal, or aluminum nitrates; alkali metal, alkaline earth metal, or aluminum nitrites; alkali metal, alkaline earth metal, or aluminum thiocyanates; alkanolamines; alkali metal, alkaline earth metal, or aluminum thiosulfates; alkali metal, alkaline earth metal, or aluminum hydroxides; alkali metal, alkaline earth metal, or aluminum carboxylates (preferably calcium formate); polyhydroxyalkylamines; and alkali metal or alkaline earth metal halide salts (e.g., chlorides). Stable CSH seeds may also be used as accelerators.

[0032] In certain embodiments, the accelerator may include one or more soluble organic compounds, such as one or more alkanolamines, such as triethylamine (TEA) and / or higher trialkanolamines or calcium formate. As used herein, the term "higher trialkanolamine" includes tertiary amine compounds that are tri(hydroxyalkyl)amines having at least one C3-C5 hydroxyalkyl (preferably C3-C4 hydroxyalkyl) group therein. If present, the remaining hydroxyalkyl groups of the tertiary amine may be selected from C1-C2 hydroxyalkyl groups (preferably C2 hydroxyalkyl). Examples of such compounds include hydroxyethyldi(hydroxypropyl)amine, di(hydroxyethyl)hydroxypropylamine, tri(hydroxypropyl)amine, hydroxyethyldi(hydroxy-n-butyl)amine, tri(2-hydroxybutyl)amine, and hydroxybutyldi(hydroxypropyl)amine. The accelerator may also include calcium salts of carboxylic acids, including acetates, propionates, or butyrates. Other organic compounds that may act as accelerators include urea, oxalic acid, lactic acid, various cyclic compounds, and condensation compounds of amines with formaldehyde.

[0033] In some embodiments, rapid-setting admixtures can be used to produce rapid-setting mortars or concrete suitable for, for example, shotcrete or 3D printing. These include ferric salts, sodium fluoride, aluminum chloride, sodium aluminate, and potassium carbonate.

[0034] Other various accelerator materials include silicates, fine silica gel, water-soluble quaternary ammonium silicates, silica fume, and finely divided magnesium or calcium carbonate. Very fine materials of various compositions may exhibit accelerator properties. In certain embodiments, the admixture may include nucleation seeds based on calcium silicate hydrate (CSH) phases. See, for example, Thomas, JJ, et al. 2009 J. Phys Chem 113:4327-4334 and Ditter et al. 2013 BFT International, Jan, pp. 44-51, which are incorporated herein by reference in their entireties.

[0035] In certain embodiments, the setting accelerator is one, two, or three of triisopropanolamine (TIPA), N,N-bis(2-hydroxyethyl)-N-(2-hydroxypropyl)amine (BHEHPA), and tri(2-hydroxybutyl)amine (T2BA), e.g., a setting accelerator including TIPA. Any suitable dosage may be, for example, 0.0001% to 0.5% bwc, e.g., 0.001% to 0.1% bwc, or 0.005% to 0.03% bwc. See U.S. Patent No. 5,084,103.

[0036] In certain embodiments, carbonation of a cement mixture is combined with the use of an admixture containing an alkanolamine set accelerator (e.g., TIPA), where the alkanolamine set accelerator (e.g., TIPA) is incorporated in an amount of 0.0001% to 0.5% bwc, e.g., 0.001% to 0.1%, or 0.005% to 0.03% bwc. In some of these embodiments, the alkanolamine (e.g., TIPA)-containing admixture is added before and / or during carbonation, e.g., as part of the initial mixwater. In some of these embodiments, the alkanolamine (e.g., TIPA)-containing admixture is added after and / or during carbonation. In some embodiments, the alkanolamine (e.g., TIPA)-containing admixture is added in two or more doses, which may be added at different times depending on the carbonation (e.g., one dose before carbonation and the other dose after carbonation). Additionally or alternatively, carbonation may proceed in more than one dose; for example, one or more alkanolamine (e.g., TIPA)-containing admixtures may be added before, after, or during the administration of carbon dioxide. Other components may also be present in alkanolamine-, e.g., TIPA-containing admixtures, including one or more set / strength modifiers, set balancers, hydration seeds, dispersants, air bubble control agents, rheology modifiers, colorants, or combinations thereof. Suitable commercially available products include BASF Master X-Seed 55 (BASF Corporation, Admixture Systems, Cleveland, OH). In these embodiments, the total dose of carbon dioxide provided to the cementitious mixture may be any suitable dose described herein, e.g., 0.001% to 2% bwc, e.g., 0.001% to 1.0% bwc, or 0.001% to 0.5% bwc.

[0037] Air scavengers: Also known as defoamers or deaerators, these agents reduce air content. Examples include nonionic surfactants such as phosphate esters, including tributyl phosphate and dibutyl phosphate, phthalate esters, including diisodecyl phthalate and dibutyl phthalate, block copolymers, including polyoxypropylene-polyoxyethylene-block copolymers, or mixtures thereof. Air scavengers also include octyl alcohol, water-insoluble esters of carbonic acid and boric acid, and silicones. Further examples of air scavengers include mineral oil, vegetable oil, fatty acids, fatty acid esters, hydroxyl-functional compounds, amides, phosphate esters, metal soaps, polymers containing propylene oxide moieties, hydrocarbons, alkoxylated hydrocarbons, alkoxylated polyalkylene oxides, acetylenic diols, polydimethylsiloxanes, dodecyl alcohol, octyl alcohol, polypropylene glycol, water-soluble esters of carbonic acid and boric acid, and low-sulfonic acid oils.

[0038] Air-entraining admixture: The term air-entraining agent includes any substance that entrains air in a cementitious composition. Some air-entraining agents can also reduce the surface tension of the composition at low concentrations. Air-entraining agents are used to intentionally entrain fine air bubbles into concrete. Air entrainment dramatically improves the durability of concrete exposed to moisture during freeze-thaw cycles. Furthermore, the entrained air greatly improves concrete's resistance to surface scaling caused by chemical de-icers. Air entrainment also increases the workability of fresh concrete while eliminating or reducing material segregation and bleeding. Materials used to achieve these desired effects can be selected from wood resins and their salts, natural resins and their salts, synthetic resins and their salts, sulfonated lignins and their salts, petroleum acids and their salts, protein materials and their salts, fatty acids and their salts, resin acids and their salts, alkylbenzene sulfonates, sulfonated hydrocarbons, vinsol resins, anionic surfactants, cationic surfactants, nonionic surfactants, natural rosin, synthetic rosin, inorganic air entraining agents, synthetic detergents, and their corresponding salts, and mixtures thereof. Solid materials such as hollow plastic spheres, crushed brick, expanded clay or shale, or suitable diatomaceous earth spheres can also be used. The air entraining agent is added in an amount to provide the desired level of air in the cementitious composition. Examples of air entraining agents that can be used in the admixture system include, but are not limited to, MB AE 90, MB VR, and MICRO AIR.RTM., all available from BASF Admixtures Inc. of Cleveland, Ohio.

[0039] Alkali-aggregate reaction inhibitors: reduce the spread of alkali-aggregate reactivity. Examples include barium salts, lithium nitrate, lithium carbonate, and lithium hydroxide.

[0040] Non-segregating admixtures: adhesive concrete for underwater placement. Examples include cellulose and acrylic polymers.

[0041] Bonding admixtures: Increase adhesive strength. Examples include polyvinyl chloride, polyvinyl acetate, acrylic resins, and butadiene-styrene copolymers.

[0042] Colorants: Colored concrete. Examples include modified carbon black, iron oxide, phthalocyanine, amber, chromium oxide, titanium oxide, cobalt blue, and organic colorants.

[0043] Rust inhibitors: Reduce steel corrosion activity in chloride-containing environments. Examples include calcium nitrite, sodium nitrite, sodium benzoate, certain phosphates or fluorosilicates, fluoroaluminates, and esteramines.

[0044] Moisture-resistant admixtures: Impede the penetration of moisture into dry concrete. Examples include calcium or ammonium stearate or oleate, butyl stearate, and petroleum soaps.

[0045] Foaming agents: Produce low-density lightweight cellular concrete. Examples include cationic and anionic surfactants, and hydrolyzed proteins.

[0046] Moldcides, bactericides, and insecticides: inhibit or suppress the growth of bacteria and fungi. Examples include polyhalogenated phenols, dieldrin emulsions, and copper compounds.

[0047] Foaming Agents: Foaming agents, or gas-generating agents, are sometimes added to concrete and grout in very small amounts to cause a slight expansion before hardening. The amount of expansion depends on the amount of gas-generating material used and the temperature of the fresh mix. Aluminum powder, resin soaps and vegetable or animal glues, saponins, or hydrolyzed proteins can be used as foaming agents.

[0048] Hydration control agents: stabilizers and activators are used to interrupt and reactivate cement hydration. Examples include carboxylic acids and phosphorus-containing organic acid salts.

[0049] Permeability reducers: Reduces permeability. Examples include latex and calcium stearate.

[0050] Pumping aids: improve pumpability. Examples include organic and synthetic polymers, organic flocculants, organic emulsions of paraffin, coal tar, asphalt, acrylic resins, ventolite and pyrogenic silica, and hydrated lime.

[0051] Retarders: may include water-reducing retarders (see water-reducing admixtures), which delay setting time, reducing the water requirement of the concrete mix for a given slump and increasing the time to set, or those that increase the setting time of concrete without affecting water requirement. Generally, set retarders can be divided into four categories: 1) lignosulfonic acids and their salts and their modifications and derivatives; 2) hydroxylated carboxylic acids and their salts and their modifications and derivatives; 3) carbohydrate-based compounds such as sugars, sugar acids, and polysaccharides; and 4) inorganic salts such as borates and phosphates, any of which may be used in embodiments herein. Thus, set retarders include carbohydrates, i.e., sugars such as fructose, glucose, and sucrose, as well as sugar acids / bases and their salts, such as sodium gluconate and sodium glucoheptonate; phosphonates, such as nitrilotri(methylphosphonic acid), 2-phosphonobutane-1,2,4-tricarboxylic acid; and chelating agents, such as EDTA, citric acid, and nitrilotriacetic acid. Other sugars and sugar-containing admixes include molasses and corn syrup. In certain embodiments, the admixing agent is sodium gluconate. Other exemplary admixtures that can be used as set retarders include sodium sulfate, citric acid, BASF Pozzolith XR, femtosilica, colloidal silica, hydroxyethyl cellulose, hydroxypropyl cellulose, fly ash (as defined in ASTM C618), mineral oil (such as light naphthenic), hectorite clay, polyoxyalkylene, natural rubber, or mixtures thereof, polycarboxylic acid superplasticizers, naphthalene HRWR (high performance water reducer). Additional set retarders that can be used include, but are not limited to, oxy-boron compounds, lignin, polyphosphonic acids, carboxylic acids, hydroxycarboxylic acids, polycarboxylic acids, hydroxylated carboxylic acids such as fumaric acid, itaconic acid, malonic acid, borax, gluconic acid, and tartaric acid, lignin sulfonic acid, ascorbic acid, isoascorbic acid, sulfonic acid-acrylic acid copolymers and their corresponding salts, polyhydroxysilanes, and polyacrylamides.Further retarders include nitrilotri(methylphosphonic acid) and 2-phosphonobutane-1,2,4-tricarboxylic acid. For illustrative examples of retarders, see U.S. Patent Nos. 5,427,617 and 5,203,919, which are incorporated herein by reference.

[0052] Shrinkage control agents: reduce drying shrinkage. Examples include polyoxyalkylene alkyl ethers and propylene glycol.

[0053] Water-reducing admixtures: Water-reducing admixtures (also called dispersants, especially HRWRs) are used to reduce the amount of admixture water required to produce concrete of a given slump, lower the water-cement ratio, reduce the cement content, or increase the slump. Typical water-reducing admixtures reduce the water content by approximately 5% to 10%; high-performance water-reducing admixtures (HRWRs) reduce the water content even further. Mixes with higher slumps can be produced by adding water-reducing admixtures to concrete without reducing the water content. For example, in certain cases, using a high dose of carbon dioxide to carbonate the cement mixture can reduce the slump, and water-reducing admixtures may be used to restore full slump / workability.

[0054] The water-reducing admixtures used in the compositions and methods herein may conform to one of the seven types of water-reducing admixtures in ASTM C494 / C494M, which are defined as follows: 1) Type A - water-reducing admixtures; 2) Type B - retarders (as described above); 3) Type C - accelerators (also described above); 4) Type D - water-reducing and retarding admixtures; 5) Type E - water-reducing and accelerators; 6) Type F - superplasticizers; or 7) Type G - superplasticizers and retarding admixtures. Materials commonly usable as water reducers typically fall into one of seven general categories, and formulations useful herein include compounds from several of the following categories, but are not limited to: 1) lignosulfonic acids and their salts and their modifications and derivatives; 2) hydroxylated carboxylic acids and their salts and their modifications and derivatives; 3) carbohydrate-based compounds such as sugars, sugar acids, and polysaccharides; 4) salts of sulfonated melamine polycondensation products; 5) salts of sulfonated naphthalene polycondensation products; 6) polycarboxylates; 7) nonionic surfactants; amines and their derivatives; organic phosphonates, including zinc salts, borates, phosphates; and other materials that may be used to modify the formulation, including certain polymeric compounds, including cellulose ethers, silicones, and sulfonated hydrocarbon acrylate derivatives.

[0055] Generally, the use of water-reducing admixtures improves strength by decreasing the water-cement ratio. For concrete with equal cement content, air content, and slump, the 28-day strength of water-reducing concrete containing water-reducing admixtures is 10% to 25% higher than that of concrete without admixtures. Type A water-reducing admixtures have little effect on setting, while Type D admixtures provide water reduction with retardation (generally with the addition of a retarder), and Type E admixtures provide water reduction with set acceleration (generally with the addition of an accelerator). Type D water-reducing admixtures typically delay the setting time of concrete by 1 to 3 hours. Some water-reducing admixtures may also entrain some air into the concrete.

[0056] High-range water reducers (HRWRs, also called superplasticizers or superplasticizers), Types F (water reducing) and G (water reducing and retarding), reduce the water content by at least 12%.

[0057] Examples of water reducers include lignosulfonates, casein, hydroxylated carboxylic acids, and carbohydrates. Additional examples, including HRWRs (high flow agents or superplasticizers), include polycarboxylic acid ethers, polycarboxylates, polynaphthalene sulfonates (sulfonated naphthalene formaldehyde condensates (e.g., LOMAR D™ dispersant (Cognis Inc., Cincinnati, Ohio)), polymelamine sulfonates (sulfonated melamine formaldehyde condensates), polyoxyethylene phosphonates (phosphonate-terminated PEG brushes), and vinyl copolymers. Further examples include beta-naphthalene sulfonates, polyaspartates, or oligomeric dispersants.

[0058] Polycarboxylic acid dispersants (water reducers also called polycarboxylic acid ethers, polycarboxylic acid esters) can be used, which means dispersants having a carbon skeleton with pendant side chains, at least some of which are attached to the main chain via carboxyl or ether groups. Examples of polycarboxylate dispersants are described in U.S. Patent Publication No. 2002 / 0019459A1, U.S. Patent Nos. 6,267,814, 6,290,770, 6,310,143, 6,187,841, 5,158,996, 6,008,275, 6,136,950, 6,284,867, 5,609,681, 5,494,516, 5,674,929, 5,660,626, 5,668,195, 5,661,20 5,633,298, 5,583,183, and 5,393,343. Polycarboxylic acid dispersants of interest include, but are not limited to, dispersants or water reducers sold under the following trademarks: GLENIUM® 3030NS, GLENIUM® 3200 HES, GLENIUM 3000NS® (BASF Admixtures Inc., Cleveland, Ohio), ADVA® (WR Grace Inc., Cambridge, Mass.), VISCOCRETE® (Sika, Zurich, Switzerland), and SUPERFLUX® (Axim Concrete Technologies Inc., Middlebranch, Ohio).

[0059] Viscosity and Rheology Modifiers Viscosity modifiers (VMAs) are typically water-soluble polymers used in concrete to adjust its rheological properties. VMAs affect the rheology of concrete by increasing its plastic viscosity, and the effect of yield stress varies greatly depending on the type of VMA, ranging from no increase to a significant increase. Plastic viscosity is defined as the property of a material to resist changes in the shape or arrangement of its elements during flow, and yield stress is defined as the critical shear stress value below which a viscoplastic material will not flow and, once exceeded, will flow like a viscous liquid. Rheology modifiers can be used to adjust, for example, increase, the viscosity of cementitious compositions. Suitable examples of rheology modifiers include fumed silica, colloidal silica, cellulose ethers (e.g., hydroxyethyl cellulose, hydroxypropyl methylcellulose), fly ash (as specified in ASTM C618), mineral oil (such as light naphthenic), hectorite clay, polyoxyalkylenes, polysaccharides, polyethylene oxide, polyacrylamide or polyvinyl alcohol, natural and synthetic rubbers, alginates (derived from seaweed), or mixtures thereof. Other materials include fine solids such as starch, clay, lime, and polymer emulsions. Rheology modifiers (RMAs) are admixtures that affect the flow properties of concrete by reducing the yield stress or force required to initiate flow without necessarily changing the plastic viscosity. The addition of RMAs to concrete does not change its slump but improves its workability and flow properties. RMAs have been used in low-slump concrete applications, for example, when concrete is placed using slip-form pavers to place concrete pavers, curbs, and barriers, and potentially in 3D printing. They can also be used in self-compacting concrete (SCC) or high-flow concrete. Rheology modifiers include those reported by Bury and Bury, 2008, Concrete International, 30:42-45, which is incorporated herein by reference in its entirety.

[0060] Shrinkage reducing and compensating agents Shrinkage compensators that can be used in cementitious compositions include RO(AO)1- 10 H, where R is C 1-5 Alkyl or C 5- 6 cycloalkyl radical and A is C 2-3 Alkylene radicals, alkali metal sulfates, alkaline earth metal sulfates, alkaline earth oxides, preferably sodium sulfate and calcium oxide. TETRAGUARD® is an example of a shrinkage reducing agent and is available from BASF Admixtures, Inc. (Cleveland, Ohio). Exemplary shrinkage reducing agents (SRAs) include polyoxyalkylene alkyl ethers or similar compositions. Exemplary shrinkage compensating agents (SCAs) include calcium sulfoaluminate and calcium aluminate, calcium hydroxide, magnesium oxide, hard-burned and dead-burned magnesium oxide.

[0061] Long-term setting control agent Long-term set control agents (ESCA) or hydration control agents (HCA) are used to stop or significantly slow the cement hydration process in unhardened concrete. They may be used to shut down the ongoing hydration of cementitious products in returned / waste concrete or in wash water processed in trucks or concrete reclaimer systems, allowing these products to be recycled back into concrete production, thereby eliminating the need for disposal, or to stabilize newly batched concrete, providing moderate to very long-term set retardation, allowing the concrete to remain plastic during very long transports or long-distance pumping situations that require a longer slump life in a more predictable manner than conventional retarders. These differ from traditional set control agents because they stop the hydration process of both the silicate and aluminate phases in Portland cement. Conventional set control admixtures only affect the silicate phase. Examples include carboxylic and phosphorus-containing organic acids and salts.

[0062] Workability retention agent Helps maintain the workability of concrete. Examples include hydration control and retarders meeting the requirements of ASTM C494 / C494M Type B or D, or neutral set workability retainers meeting the requirements of ASTM C494 / C494M Type S. See Daczko, 2010, Proceedings for the 6th International Symposium on Self-compacting Concrete and the 4th North American Conference on the Design and Use of Self-Consolidating Concrete, Sept.

[0063] Corrosion inhibitors Reduces corrosion of steel in concrete, e.g., rebar. Examples include chromates, phosphates, hydrophosphates, alkalis, nitrites, and fluorides; amine carboxylates, amine ester organic emulsions, and calcium nitrite.

[0064] Permeability Reducer Permeability reducing additives (PRAs) have been developed to improve the durability of concrete by controlling water and moisture movement and reducing chloride ion ingress and permeability. Typical examples include: 1) hydrophobic waterproofing agents, e.g., materials based on soaps and long-chain fatty acid derivatives, vegetable oils such as tallow, soy-based materials, and grease, and petroleum oils such as mineral oil and paraffin wax, e.g., calcium, ammonium, and butyl stearates; 2) polymeric products, e.g., organic hydrocarbons supplied either in emulsion (latex) or liquid form, e.g., coal tar pitch, bitumen, or other resinous polymers, or prepolymer materials; 3) finely divided solids, e.g., inert and chemically active fillers, e.g., talc, bentonite, siliceous powders, clay, lime, silicates, and colloidal silica, supplementary cementitious materials (SCMs) such as fly ash, raw or calcined natural pozzolans, silica fume, or slag cement, which are not technically chemical admixtures but may contribute to reducing the permeability of concrete as a complementary element; 4) hydrophobic pore blockers; and 5) crystalline products, which may be the sole active chemical provided in a cement and sand carrier.

[0065] The binding admixture comprises an organic polymer (latex) dispersed in water.

[0066] Colorants include natural or synthetic materials in liquid or dry form. Pigments include black iron oxide, carbon black, phthalocyanine blue, cobalt blue, red iron oxide, brown iron oxide, raw burnt umber, chromium oxide, phthalocyanine green, yellow iron oxide, titanium dioxide, and the like.

[0067] Flocculants include synthetic polyelectrolytes, such as vinyl acetate-maleic anhydride copolymers.

[0068] Fungicides, bactericides and insecticides include polyhalogenated phenols, dieldrin emulsions, and copper compounds.

[0069] Lithium admixtures to reduce harmful expansion from alkali-silica reactions Harmful expansion from alkali-silica reaction (ASR) can occur in concrete when susceptible siliceous minerals are present in the aggregate. Exemplary admixtures that prevent these harmful expansion reactions include solid forms (lithium hydroxide monohydrate and lithium carbonate) and liquid forms (30 wt. % aqueous lithium nitrate solution). A further example includes lithium nitrite.

[0070] Inflating / gas generating agents include metallic aluminum, zinc, or magnesium, hydrogen peroxide, nitrogen and ammonium compounds, and certain forms of activated carbon or fluid coke.

[0071] Admixtures for aerated concrete / flowable fill include those based on proteins or synthetic surfactants.

[0072] Shotcrete admixture Shotcrete is defined as "mortar or concrete sprayed onto a surface at high speed." Materials useful as shotcrete admixtures include alkali-based accelerators, such as aqueous silicate or aluminate solutions, or alkali-free accelerators, such as those based on aluminum sulfate and aluminum hydroxysulfate; superplasticizers, such as those known in the art specially formulated for shotcrete mixtures; and long-set control admixtures.

[0073] Admixture for manufactured concrete products These may be used to add production efficiencies, improve or modify surface texture, enhance and maintain visual appeal, or provide value-added performance benefits. These include flow agents such as soaps, surfactants, lubricants, and cement dispersants; accelerators, both calcium chloride and non-chloride; and waterproofing / efflorescence control agents such as calcium / aluminum stearate, fatty acids, silicone emulsions, and wax emulsions.

[0074] Admixture for fluidizing concrete Flowing concrete is defined as "concrete characterized by a slump of greater than 7.5 inches (190 mm) while maintaining resistance to segregation." As described herein, a variety of admixtures may be used, including medium and high performance water reducers, viscosity modifiers, set retarders, set accelerators, and workability retainers.

[0075] Admixtures for Self-Compacting Concrete (SCC) Exemplary admixtures included in SCC include superplasticizers, e.g., polycarboxylic acid-based HRWRAs, such as blends of different polycarboxylic acid polymers with different absorption rates on powder substrates; and viscosity modifiers.

[0076] Admixture for ultra-cold weather concrete They allow concrete to be poured at temperatures below freezing and include water reducers, accelerators, retarders, corrosion inhibitors, and shrinkage reducers (due to their freezing point depressing effect).

[0077] Admixture for ultra-high early strength concrete VHESC is designed to achieve very high early strength within the first few hours after pouring. The admixture system may include a superplasticizer, a set accelerator, and optionally an air entrainer. It may also include a workability-retaining admixture.

[0078] Admixture for permeable concrete Pervious concrete is a low-slump, open-graded material consisting of Portland cement, uniformly sized aggregate, little or no fine aggregate, chemical admixtures, and water, which, when combined, produces hardened concrete with interconnected pores or voids that allow water to pass easily through the concrete. Exemplary admixtures include air entrainers, long-term set controllers, water reducers, internal curing agents, viscosity modifiers, and latex admixtures.

[0079] Admixture for 3D printing concrete It includes admixtures that allow the printed concrete to stand without any other admixtures and in a form suited to the requirements of 3D printing.

[0080] In certain embodiments, the admixture may include a commercially available admixture. In certain embodiments, the admixture may include one or more components of a commercially available admixture. See Table 2 for a non-exhaustive list of commercially available admixtures and their formulations. It should be understood that any suitable admixture or admixture component may be used. In certain embodiments, the admixture solution includes one of the components included in a commercially available admixture, but at a different concentration compared to one or more other components within the same commercially available admixture. In certain embodiments, the admixture solution includes a commercially available admixture component and one or more additional admixture components. In these embodiments, the admixture exhibits improved performance when used with carbonated cement.

[0081] Modification or Influence of Calcium Carbonate In certain embodiments, admixtures are used that modify the formation of calcium carbonate, e.g., modify the formation of amorphous calcium carbonate, e.g., aragonite or calcite, so that, for example, one or more polymorphic forms are favored compared to a mixture without the admixture. Exemplary admixtures of this type include organic polymers, e.g., polyacrylates and polycarboxylic acid ethers, phosphate esters, e.g., hydroxyaminophosphate esters, phosphonates and phosphonic acids, e.g., nitrilotri(methylphosphonic acid), 2-phosphonobutane-1,2,4-tricarboxylic acid, chelating agents, e.g., sodium gluconate, ethylenediaminetetraacetic acid (EDTA), and citric acid, or surfactants, e.g., calcium stearate.

[0082] Additional admixtures of interest include those that affect calcium carbonate formation, reactions, and other aspects of calcium carbonate. For example, magnesium can be a strong inhibitor of calcite growth, and the Mg / Ca ratio can affect the shelf life of amorphous calcium carbonate, e.g., a high ratio increases shelf life, and can affect the type of crystalline polymorph that forms as an initial and long-term product. 2- / Ca 2+ Similar to physical mixing, the chemical and physical properties of the mixture may also affect these, and either or both may be manipulated. See, e.g., Blue, C.R., Giuffre, A., Mergelsberg, S., Han, N., De Yoreo, J.J., Dove, P.M., 2017. Chemical and physical controls on the transformation of amorphous calcium carbonate into crystalline CaCO3 polymorphs. Geochimica et Cosmochimica Acta 196, 179-196. https: / / doi.org / 10.1016 / j.gca.2016.09.004, the entire contents of which are incorporated herein by reference.

[0083] In certain embodiments, the admixture may include one or more 2D substrates with terminal functional groups, which may also affect the crystal phase, size, shape, and / or orientation. Exemplary strategies for preparing functionalized substrates include Langmuir monolayers, surface carbonylation, and alkanethiol self-assembled monolayers (SAMs). For example, stearic acid monolayers have been used to direct CaCO3 crystallization. Various functional groups can be micropatterned on the substrate to induce CaCO3 crystallization. Thus, in certain embodiments, 2D substrates with -COOH, -NH2, -OH, SO3H, -CH3, -SH, and / or PO4H2 can be used to control the mineralization of CaCO3. The physical and / or chemical properties of the substrate may be manipulated to suit the desired results. These include the chemical nature, hydrophilicity, charge (or coordination number) and geometry (or spatial structure) of the terminal functional groups, the substrate metal, and the length of the alkanethiol molecules. Additionally or alternatively, temperature and / or Ca ++ Environmental factors, such as the initial concentration of ACC, may be manipulated. ACC formation and conversion may be favored on strongly hydrophilic surfaces, e.g., -OH or -SH terminated SAMs. Without being bound by theory, it is believed that CaCO3 nucleates via the same mechanism as -OH, NH2, and -CH3 terminated SAMs. Poly(ethylene glycol) (PEG)-based double hydrophilic block copolymers, carboxylated polyaniline (c-PANI), can be used to mediate CaCO3 crystallization and provide control over crystal size, shape, and modification, for example, facilitating the production of purely crystalline calcite and / or vaterite. The addition of -OH and -COOH compatible functional polymers may stabilize the ACC precursor phase, which may gradually convert to calcite if desired. Additionally or alternatively, charged functional groups can be added to CaCO3. 2+ions to promote CaCO crystallization. See, e.g., Deng, H., Shen, X.-C., Wang, X.-M., Du, C., 2013. Calcium carbonate crystallization controlled by functional groups: A mini-review. Frontiers of Materials Science 7, 62-68. https: / / doi.org / 10.1007 / s11706-013-0191-y, which is incorporated herein by reference in its entirety, and in particular Table 1 for the potential effect of various admixtures on morphology.

[0084] In certain embodiments, the admixture may include one or more complexing agents, such as ethylenediaminetetraacetic acid (EDTA) and / or 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP). For example, without being bound by theory, EDTA has been reported to retard the crystal growth of calcite and aragonite. Aquasoft 330, a commercial grade of HEDP, has been reported to control the morphology of CaCO3 and calcium oxalate. See, e.g., Gopi, SP, Subramanian, VK, Palanisamy, K., 2015. Synergistic Effect of EDTA and HEDP on the Crystal Growth, Polymorphism, and Morphology of CaCO3. Industrial & Engineering Chemistry Research 54, 3618-3625. https: / / doi.org / 10.1021 / ie5034039, the entire contents of which are incorporated herein by reference.

[0085] In certain embodiments, admixtures can include low-molecular-weight and polymeric additives, such as block copolymers, poly(ethylene glycol) (PEG), polyelectrolytes, polyacrylamides, and cellulose, which can significantly affect the crystallization of CaCO3. See, for example, Xie et al., 2006; Xu et al., 2008; Xu et al., 2011; Sadowski et al., 2010; Su et al., 2010, all of which are incorporated herein by reference in their entireties. Among various templates, PEG is particularly interesting because its molecules contain hydrophilic groups, which can act as donors for metal ions to form metal complexes with diverse conformations. CaCO3 mineralized without PEG polymer formed rhombohedral calcite crystals with average sizes of 12.5 and 21.5 μm after 5 minutes and 24 hours of incubation, respectively. In contrast, CaCO3 precipitates obtained in the presence of PEG but recovered after 24 hours of incubation exhibited particles with diameters ranging from 13.4 to 15.9 μm. The slight increase in particle size observed at higher polymer concentrations may be caused by aggregation effects. Therefore, without being bound by theory, it is believed that the presence of poly(ethylene glycol) inhibits the growth of CaCO3 particles in the system. It is known that low- and high-molecular-weight additives can stabilize non-equilibrium morphologies by altering the relative growth rates of different crystallographic planes through specific molecular interactions with certain surfaces that alter the surface energy or growth mechanism, or both. Furthermore, without being bound by theory, in aqueous solutions, Ca 2+ and CO3 2-It is believed that ACC first forms, which rapidly transforms into vaterite and calcite within minutes, but at the same time, polymer molecules adsorb onto the particle surface, which may inhibit crystal growth during the process and cause the formation of small particles. See, e.g., Polowczyk, I., Bastrzyk, A., Kozlecki, T., Sadowski, Z., 2013. Calcium carbonate mineralization. Part 1: The effect of poly(ethyleneglycol) concentration on the formation of precipitate. Faculty of Geoengineering, Mining and Geology, Wroclaw University of Technology, Wroclaw. https: / / doi.org / 10.5277 / ppmp130222, the entire contents of which are incorporated herein by reference.

[0086] In certain embodiments, the admixture may include a water-soluble polymer as a soluble additive, which may affect, for example, the crystallization of CaCO3; such additives may be present with an insoluble matrix. Exemplary soluble additives include poly(acrylic acid) (PAA); PAAm: poly(allylamine); PGA: poly(glutamic acid) sodium salt; and DNA: deoxyribonucleic acid (DNA), such as the sodium salt from salmon sperm (DNA). These admixtures may be used with one or more substrates, such as glass, poly(ethylene-co-acrylic acid) (PEAA) (20% acrylic acid by weight), or chitosan. PEAA and chitosan contain carboxylic acid and amino groups, respectively. These polymers can be spin-coated onto glass substrates. In the absence of a soluble additive, rhombohedral calcite crystals can grow on all three substrates. Different substrate / polymer combinations may have different effects. For example, in the case of glass, there is no crystallization with PAA or PAAm, whereas spherical crystals can be obtained with PGA additives (vaterite and calcite) or DNA (calcite). The same effect is observed with additives on PEAA. Chitosan, PAA, and PGA can give thin films of CaCO3. Without being bound by theory, the carboxylic acid groups of PAA and PGA and the amino groups of chitosan may interact, resulting in the formation of thin film crystals. Spherical particles grow sporadically on the surface in the presence of DNA. For a further discussion of these potential admixtures, see, e.g., Kato, T., Suzuki, T., Amamiya, T., Irie, T., Komiyama, M., Yui, H., 1998. Effects of macromolecules on the crystallization of CaCO3 the Formation of Organic / Inorganic Composites. Supramolecular Science 5, 411-415. https: / / doi.org / 10.1016 / S0968-5677(98)00041-8, which is incorporated herein by reference in its entirety.

[0087] The (or each) admixture may be added in any suitable final proportion (bwc) of cement, for example in the range of 0.01% to 0.5%, or 0.01% to 0.3%, or 0.01% to 0.2%, or 0.01% to 0.1%, or 0.01% to 1.0%, or 0.01% to 0.05%, or 0.05% to 5%, or 0.05% to 1%, or 0.05% to 0.5%, or 0.1% to 1%, or 0.1% to 0.8%, or 0.1% to 0.7%. The admixture (or each admixture in an admixture combination) may not exceed 0.0001%, 0.0002%, 0.0005%, 0.001%, 0.002%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1.0% bwc in final proportions greater than may be added, and in certain cases may be added in final percentages of less than 10%, 5%, 4%, 3%, 2%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.005%, 0.002%, 0.001%, 0.0005%, or 0.002% bwc. Other ranges and amounts are as described herein.

[0088] In certain embodiments, carbonation and the use of an admixture as described herein improves strength, such as compressive strength as measured by a standard test, at one or more time points, e.g., 1 day, 7 days, or 28 days. In certain embodiments, carbonation and the use of an admixture containing an accelerant improves strength at at least two time points, e.g., 1 day, 7 days, or 28 days, and in certain embodiments, carbonation and the use of an admixture containing an accelerant improves strength at all time points, e.g., 1 day, 7 days, or 28 days. At any point, strength may be increased by at least 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 17%, 20%, 22%, 25%, 27%, 30%, 32%, 35%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% compared to the same cementitious mixture without carbonation and the accelerator-containing admixture.

[0089] Other advantages compared to the same mix without carbonation and admixtures include a wider strength safety factor and / or performance range, reduced cost of in-situ concrete, the ability to allow higher replacement rates of supplementary cementitious materials (SCMs), the possibility of early removal and reuse of formwork, and a reduction in the carbon dioxide emissions associated with concrete due to reduced absorbed carbon dioxide and the amount of cement required to achieve a given strength. Further benefits include reduced water content at the same workability level or improved workability at the same water content when compared to untreated reference concrete, normal setting characteristics, high early strength, excellent slump retention, high ultimate strength, optimum setting time, consistent air entrainment, dosage flexibility, reduced drying shrinkage (e.g., up to 80% at 28 days and up to 50% after one year), reduced stress due to one-dimensional surface drying in concrete slabs and floors, reduced carbonation (atmospheric) after pouring, excellent pumpability and / or finishability, improved flexural strength at one or more ages, retarded set (e.g., controllable set retardation depending on dosage), occurrence of dead load deflections before the concrete hardens during long pours such as bridge decks, cantilevers, and structural elements without formwork, minimal bleeding water, cohesive and non-segregating properties, extended plastic range, extended slump retention, and optimum dispersion of cement and pigments.Benefits include: faster concrete placement, high performance water reducing for high slump applications, rapid strength development for energy savings and early formwork removal (for precast / prestressed concrete applications), early structural utilization of concrete, consistency of pouring operations, optimized mix costs, reduced repair costs, achieving the difficult combination of high early strength and high long-term compressive strength, increased productivity, improved operational efficiency, reduced quality control (QC) support, reduced rejected loads, early formwork repurposing, preservation of workability without delay, aesthetics due to reduced drying shrinkage cracking and microcracking, improved waterproofing and durability, reduced prestress loss, reduced warping, improved resistance to damage from freeze-thaw cycles, improved resistance to scaling from deicing salts, and improved permeability. These benefits include improved waterproofing due to reduced water retention, reduced segregation and bleeding, longer service life, superior finishing characteristics for flat and cast surfaces, flexibility in scheduling pouring and finishing operations, offsetting the effects of premature curing due to long delays between mixing and pouring, prevention of cold joints, reduced peak temperatures and / or temperature rise rates in mass concrete to reduce thermal cracking, higher modulus of elasticity, improved bond strength to rebar, improved visual aesthetics, potential for reduced cement and colorant usage, extended life of formwork and other machine components (e.g., in the production of blocks, pavers, dry-cast products, etc.), greater tolerance for variations in water content in the mix and therefore improved uniform mix characteristics at high water-to-crack ratios (w / c). Additionally, structures using carbonated admixtures have increased durability and reduced / delayed maintenance and replacement costs, resulting in a longer service life and further reduced carbon footprint.

[0090] In certain embodiments, methods and compositions include a cement mixture, e.g., a concrete mixture, to which carbon dioxide and at least one accelerator are added. The carbon dioxide can be added in any suitable dosage, e.g., dosages described herein, e.g., dosages ranging from 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5%. The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The accelerator may be added with the cement, for example, in a co-ground form, with the cement, with the admixture water, or after mixing has begun, in a single charge or in two, three, four, five, or more than five separate charges. When a charge of accelerator is added to the admixture water, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide, as described herein, may be added at any suitable time after the accelerator is added (i.e., after mixing has begun). Additional accelerators may be added during or after the carbon dioxide addition. As will be understood, the amounts and timing described herein may be used in any suitable combination. Suitable accelerators include those described herein. In certain embodiments, accelerators comprising one or more alkanolamines, such as triethylamine (TEA) and / or higher trialkanolamines, are used. As used herein, the term "higher trialkanolamine" includes tertiary amine compounds that are tri(hydroxyalkyl)amines having at least one C3-C5 hydroxyalkyl (preferably C3-C4 hydroxyalkyl) group therein. If present, any remaining hydroxyalkyl groups of the tertiary amine of interest may be selected from C1-C2 hydroxyalkyl groups (preferably C2 hydroxyalkyl).Examples of such compounds include hydroxyethyldi(hydroxypropyl)amine, di(hydroxyethyl)hydroxypropylamine, tri(hydroxypropyl)amine, hydroxyethyldi(hydroxy-n-butyl)amine, tri(2-hydroxybutyl)amine, and hydroxybutyldi(hydroxypropyl)amine. In certain embodiments, the setting accelerator is one, two, or three of triisopropanolamine (TIPA), N,N-bis(2-hydroxyethyl)-N-(2-hydroxypropyl)amine (BHEHPA), and tri(2-hydroxybutyl)amine (T2BA), e.g., a setting accelerator including TIPA. Any suitable dosage can be, for example, 0.0001% to 0.5% bwc, e.g., 0.001% to 0.1%, or 0.005% to 0.03% bwc. See U.S. Patent No. 5,084,103. Additional admixtures may include one or more of a set balancer, a hydration seed, a dispersant, a foam control agent, a rheology modifier, and / or a colorant. One suitable combination of an accelerator and other admixtures includes Master X-Seed 55™ (BASF Corporation, Cleveland, OH). In certain embodiments, one or more set retarders may be used in the mixture. Suitable set retarders include those described herein. Also included are compositions provided by these methods.

[0091] In certain embodiments, methods and compositions include a cementitious mixture, e.g., a concrete mixture, to which carbon dioxide is added and at least one admixture, e.g., a set retarder, that counteracts the accelerating effect of CO2 is added. The carbon dioxide can be added in any suitable dosage, e.g., dosages described herein, e.g., dosages ranging from 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5%. The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The admixture (e.g., retarder) capable of counteracting the accelerating effect of CO may be added with the cement, e.g., co-ground, with the cement, with the mixwater, after mixing has begun, or any combination thereof, in a single charge or in two, three, four, five, or more separate charges. When the admixture (e.g., retarder) capable of counteracting the accelerating effect of CO is added to the mixwater, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide, as described herein, may be added at any suitable time after the admixture (e.g., retarder) capable of counteracting the accelerating effect of CO has been added (i.e., after mixing has begun). Additional admixture (e.g., retarder) capable of counteracting the accelerating effect of CO may be added during or after the addition of carbon dioxide. As will be appreciated, the dosage amounts and timing described herein may be used in any suitable combination. Suitable admixtures (e.g., retarders) capable of counteracting the accelerating effect of CO include those described herein.

[0092] In certain embodiments, the methods and compositions include a cement mixture, e.g., a concrete mixture, to which carbon dioxide has been added, and further comprising adding Ca in solution.2+ At least one admixture capable of generating or stabilizing carbon dioxide is added to the mixture. Carbon dioxide can be added in any suitable dosage, such as dosages described herein, for example, dosages ranging from 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5%. Carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. Carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide containing a mixture of gaseous and solid carbon dioxide produced from liquid carbon dioxide. Ca in solution 2+ The forming or stabilizing admixture may be added with the cement, for example, in co-ground form, with the cement, with the mixing water, or after mixing has begun, or any combination thereof, in one charge or in two, three, four, five, or more than five separate charges. 2+ If a generating or stabilizing charge of admixture is added to the admixture water, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide, as described herein, will act to dissolve the Ca in solution. 2+ It can be added at any suitable time after the forming or stabilizing admixtures have been added (i.e., after mixing has begun). 2+ Additional shaping or stabilizing admixtures may be added during or after the addition of carbon dioxide. It will be appreciated that the dosages and timings described herein may be used in any suitable combination.

[0093] In certain embodiments, methods and compositions include adding carbon dioxide to a cementitious mixture, e.g., a concrete mixture, and further adding at least one admixture that prevents coarsening or agglomeration of carbonate reaction products to the mixture. The carbon dioxide can be added in any suitable dosage, such as dosages described herein, e.g., dosages ranging from 0.001% to 10.0%, e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5% by weight of cement (bwc). The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The admixture that acts to prevent the coarsening or agglomeration of the carbonate reaction product may be added with the cement, e.g., co-ground, with the cement, with the admixture water, or after mixing has begun, or any combination thereof, in one charge or in two, three, four, five, or more than five separate charges. If a charge of the admixture that acts to prevent the coarsening or agglomeration of the carbonate reaction product is added to the admixture water, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide may be added at any suitable time after the addition of the admixture that acts to prevent the coarsening or agglomeration of the carbonate reaction product (i.e., after mixing has begun), as described herein. Additional admixture that acts to prevent the coarsening or agglomeration of the carbonate reaction product may be added during or after the addition of carbon dioxide. As will be appreciated, the charge amounts and timing described herein may be used in any suitable combination.

[0094] In certain embodiments, methods and compositions include adding carbon dioxide to a cementitious mixture, e.g., a concrete mixture, and further adding at least one admixture that functions to modify the size or shape of carbonate reaction products. The carbon dioxide can be added in any suitable dosage, e.g., dosages described herein, e.g., 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5% bwc. The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The admixture acting to modify the size or shape of the carbonate reaction product may be added with the cement, e.g., co-ground, with the cement, with the admixture water, or after mixing has begun, or any combination thereof, in a single charge or in two, three, four, five, or more separate charges. When a charge of an admixture acting to modify the size or shape of the carbonate reaction product is added to the admixture water, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide may be added at any suitable time after the addition of the admixture acting to modify the size or shape of the carbonate reaction product (i.e., after mixing has begun), as described herein. Additional admixtures acting to modify the size or shape of the carbonate reaction product may be added during or after the addition of carbon dioxide. As will be understood, the dosage amounts and timing described herein may be used in any suitable combination. Suitable admixtures acting to modify the size or shape of the carbonate reaction product include those described herein.

[0095] In certain embodiments, methods and compositions include a cementitious mixture, e.g., a concrete mixture, to which carbon dioxide is added, and further to which at least one admixture capable of promoting homogeneous nucleation of CaCO3 is added. The carbon dioxide may be added in any suitable dosage, e.g., dosages described herein, e.g., 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5% bwc. The carbon dioxide may be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide may be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The admixture capable of promoting homogeneous nucleation of CaC0 may be added with the cement, e.g., co-ground with the cement, with the admixture water, or after mixing has begun, or any combination thereof, in one charge or in two, three, four, five, or more separate charges. When a charge of an admixture capable of promoting homogeneous nucleation of CaC0 is added to the admixture water, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide may be added at any suitable time after the admixture capable of promoting homogeneous nucleation of CaC0 has been added (i.e., after mixing has begun), as described herein. Additional admixtures capable of promoting homogeneous nucleation of CaC0 may be added during or after the addition of carbon dioxide. As will be appreciated, the amounts and timings described herein may be used in any suitable combination.

[0096] In certain embodiments, methods and compositions include a cementitious mixture, e.g., a concrete mixture, to which carbon dioxide is added and at least one admixture that influences, e.g., inhibits or promotes, the interaction of CO with sulfates, ferrites, aluminates, and / or magnesium salts. The carbon dioxide can be added in any suitable dosage, e.g., dosages described herein, e.g., 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5% bwc. The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The admixture that influences, e.g., inhibits or promotes, the interaction of CO with sulfate, ferrite, aluminate, and / or magnesiumate may be added with the cement, e.g., co-ground, with the cement, with the mixwater, or after mixing has begun, or any combination thereof, in one charge or in two, three, four, five, or more than five separate charges. When a charge of an admixture that influences, e.g., inhibits or promotes, the interaction of CO with sulfate, ferrite, aluminate, and / or magnesiumate is added to the mixwater, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide may be added at any suitable time after the addition of the admixture that influences, e.g., inhibits or promotes, the interaction of CO with sulfate, ferrite, aluminate, and / or magnesiumate (i.e., after mixing has begun), as described herein. Additional admixtures that affect, e.g., inhibit or promote, the interaction of CO2 with sulfates, ferrites, aluminates, and / or magnesiumates may be added during or after the addition of carbon dioxide.As will be appreciated, the dosages and timings described herein may be used in any suitable combination.

[0097] In certain embodiments, methods and compositions include a cementitious mixture, e.g., a concrete mixture, to which carbon dioxide is added and at least one admixture that affects, e.g., inhibits or promotes, the activity of sulfates, ferrites, aluminates, and / or magnesium salts. The carbon dioxide can be added in any suitable dosage, e.g., dosages described herein, e.g., 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5% bwc. The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The admixture that influences, e.g., inhibits or promotes, the action of sulfate, ferrite, aluminate, and / or magnesiumate may be added with the cement, e.g., co-ground, with the cement, with the mixwater, or after mixing has begun, or any combination thereof, in a single charge or in two, three, four, five, or more than five separate charges. When a charge of an admixture that influences, e.g., inhibits or promotes, the action of sulfate, ferrite, and / or aluminate is added to the mixwater, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide may be added at any suitable time after the addition of the admixture that influences, e.g., inhibits or promotes, the action of sulfate, ferrite, aluminate, and / or magnesiumate (i.e., after mixing has begun), as described herein. Additional admixtures that influence, e.g., inhibits or promotes, the action of sulfate, ferrite, aluminate, and / or magnesiumate may be added during or after the addition of carbon dioxide. As will be appreciated, the dosages and timings described herein may be used in any suitable combination.

[0098] In certain embodiments, methods and compositions include adding carbon dioxide to a cementitious mixture, e.g., a concrete mixture, and further adding at least one admixture to the mixture that acts to offset workability losses associated with carbonation. The carbon dioxide can be added in any suitable dosage, such as dosages described herein, e.g., 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5% bwc. The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The admixture that offsets workability loss due to carbonation may be added with the cement, e.g., co-ground, with the cement, with the mixwater, or after mixing has begun, or any combination thereof, in one charge or in two, three, four, five, or more separate charges. If a charge of the admixture that offsets workability loss due to carbonation is added to the mixwater, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide may be added at any suitable time after the admixture that offsets workability loss due to carbonation has been added (i.e., after mixing has begun), as described herein. Additional admixture that offsets workability loss due to carbonation may be added during or after the addition of carbon dioxide. As will be appreciated, the amounts and timing described herein may be used in any suitable combination. Suitable admixtures that act to offset the workability loss associated with carbonation include those described herein, such as plasticizers and set retarders.

[0099] In certain embodiments, methods and compositions include adding carbon dioxide to a cementitious mixture, e.g., a concrete mixture, and further adding at least one admixture to the mixture that controls, modifies, or otherwise influences the properties (e.g., size, chemical composition, and / or crystallinity) of the carbonate reaction product formed. The carbon dioxide can be added in any suitable dosage, e.g., dosages described herein, e.g., 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5% bwc. The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. The admixture that functions to control, modify, or otherwise influence the properties (e.g., size, chemical composition, and / or crystallinity) of the formed carbonate reaction product may be added with the cement, e.g., co-ground, with the cement, with the mixwater, or after mixing has begun, or any combination thereof, in one charge or in two, three, four, five, or more than five separate charges. If a charge of the admixture that functions to control, modify, or otherwise influence the properties (e.g., size, chemical composition, and / or crystallinity) of the formed carbonate reaction product is added to the mixwater, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide may be added at any suitable time after the admixture that functions to control, modify, or otherwise influence the properties (e.g., size, chemical composition, and / or crystallinity) of the formed carbonate reaction product has been added (i.e., after mixing has begun), as described herein.Additional admixtures may be added during or after the addition of carbon dioxide to control, modify, or otherwise influence the properties (e.g., size, chemical composition, and / or crystallinity) of the carbonate reaction product formed. As will be appreciated, the dosage amounts and timing described herein may be used in any suitable combination.

[0100] In certain embodiments, methods and compositions include adding carbon dioxide to a cementitious mixture, e.g., a concrete mixture, and further adding at least one admixture that controls, modifies, or otherwise influences the development of hydration products in carbonate products. The carbon dioxide can be added in any suitable dosage, e.g., dosages described herein, e.g., 0.001% to 10.0% by weight of cement (bwc), e.g., 0.001% to 5.0%, or 0.001% to 2.0%, or 0.001% to 1.0%, or 0.005% to 1.0%, or 0.005% to 0.5% bwc. The carbon dioxide can be added in a single dosage, or in two, three, four, five, or more than five dosages. The carbon dioxide can be added in any suitable form, such as solid carbon dioxide, e.g., carbon dioxide produced from liquid carbon dioxide, including a mixture of gaseous and solid carbon dioxide. Admixtures that control, modify, or otherwise influence the development of hydration products in the carbonate product may be added with the cement, e.g., co-ground, with the cement, with the mixwater, or after mixing has begun, or any combination thereof, in a single charge or in two, three, four, five, or more than five separate charges. When a charge of an admixture that controls, modifies, or otherwise influences the development of hydration products in the carbonate product is added to the mixwater, it will generally be present before the addition of carbon dioxide. In this case, carbon dioxide may be added at any suitable time after the addition of the admixture that controls, modifies, or otherwise influences the development of hydration products in the carbonate product (i.e., after mixing has begun), as described herein. Additional admixtures that control, modify, or otherwise influence the development of hydration products in the carbonate product may be added during or after the addition of carbon dioxide. As will be appreciated, the doses and timings described herein may be used in any suitable combination.Suitable admixtures include anionic surfactants, such as sodium dodecyl sulfate (SDS), and cationic surfactants, such as cetyltrimethylammonium bromide (CTAB), cetylpyridinium bromide (CPB), and tetra(decyl)ammonium bromide (TDAB). The presence of certain anions can also control the formation of hydration products in carbonate products. Thus, in certain embodiments, admixtures can include nitrates, chlorides, or hydroxides, such as nitrates. See, for example, Moghaddam et al., J. Materials Chem. A, DOI 10 1039 / c6ta09389b, 2016.

[0101] In certain embodiments, there is provided a method for producing a cement mixture, the method comprising mixing a hydraulic cement such as Portland cement, e.g., OPC, with carbon dioxide and an admixture. In certain embodiments, the admixture comprises a dispersant, a water-reducing admixture, an air-entraining agent, or a combination thereof. In certain embodiments, the admixture comprises a polyacrylate such as sodium polyacrylate; a polycarboxylate such as a polycarboxylic acid ether; a lignin such as a lignin polymer, a lignosulfate, a lignosulfonate, triethanolamine; triethanolamine (TEA); a nitrate such as sodium nitrate; a thiocyanate such as sodium thiocyanate; or a combination thereof. Carbon dioxide may be present in any suitable amount, for example, at least 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.07%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1.0%, by weight of cement (bwc), and / or 0.02%, 0.03%, 0.04%, 0.05%, 0.07%, In certain embodiments, the admixture is present in an amount of 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 2.0%, or greater than 5%, and in certain embodiments, at least 0.1%, e.g., 0.1% to 0.5%, preferably 0.1% to 0.4%, and in certain embodiments, at least 0.2%, e.g., 0.2% to 0.5%, preferably 0.3% to 0.5%. In certain embodiments, the admixture comprises a polycarboxylate or polycarboxylic acid derivative, e.g., a polycarboxylic acid ether, and the polycarboxylate or polycarboxylic acid derivative can be present in any suitable amount, e.g., 0.1% to 1% by weight, preferably 0.2% to 1% by weight, and even more preferably 0.2% to 0.8% by weight. In certain embodiments, the admixture comprises lignin or a lignin derivative, such as a lignosulfate, a lignosulfonate, or a combination thereof, and the lignin or lignin derivative is present in any suitable amount, such as from 0.2% to 8% bwc, preferably from 0.2% to 6% bwc, and even more preferably from 0.3% to 0.5% bwc.In certain embodiments, the admixture comprises a polyacrylate or polyacrylic acid derivative. The polyacrylate or polyacrylic acid derivative can be present in any suitable amount, e.g., 0.02% to 0.3% bwc, preferably 0.04% to 0.2% bwc, and even more preferably 0.06% to 0.2% bwc. In certain embodiments, when hydraulic cement is used in combination with carbon dioxide alone and / or an admixture alone, the compressive strength is lower at one or more time points than without carbon dioxide or without the admixture. The presence of carbon dioxide in the amounts described above and the presence of admixtures of the types and amounts described above can provide a cement mixture that, at one or more time points, has a compressive strength at least equal to, and often higher than, the compressive strength without the carbon dioxide and admixture. In these embodiments, the carbon dioxide and admixture exhibit a synergistic effect.

[0102] Further provided is a composition resulting from the method of the preceding paragraph, the composition comprising, for example, (i) a hydraulic cement such as Portland cement, e.g., OPC; (ii) water; (iii) carbon dioxide and / or a reaction product of carbon dioxide with the hydraulic cement, e.g., 0.01% to 2% by weight; and (iv) an admixture in an amount of 0.01% to 2% by weight. In certain embodiments, the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic acid ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate, or triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof. In certain embodiments, the admixture includes a polycarboxylate or polycarboxylic acid derivative, such as a polycarboxylic acid ether, in any suitable amount, for example, 0.1% to 1% by weight, preferably 0.2% to 1% by weight, and more preferably 0.2% to 0.8% by weight. In certain embodiments, the admixture includes a lignin or lignin derivative, such as a lignosulfate or lignosulfonate, in any suitable amount, for example, 0.2% to 8% by weight, preferably 0.2% to 6% by weight, and more preferably 0.3% to 0.5% by weight. In certain embodiments, the admixture includes a polyacrylate or polyacrylic acid derivative in any suitable amount, for example, 0.02% to 0.3% by weight, preferably 0.04% to 0.2% by weight, and more preferably 0.06% to 0.2% by weight.

[0103] Embodiment In embodiment 1, provided herein is a method for producing a cement mixture comprising mixing water, cement, carbon dioxide, an admixture, and optionally an aggregate, wherein the carbon dioxide and the admixture are combined to result in a concrete mixture that, at one or more times, has a higher compressive strength than an identical concrete mixture containing only the admixture and / or an identical concrete mixture containing only the carbon dioxide.

[0104] In embodiment 2, the present disclosure provides a composition comprising at least 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.07%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1.0% by weight of cement (bwc), and / or 0.02%, 0.03%, 0.04%, 0.05%, 0.07%, 0.1%, 0.15%, 0.2%, 0.25%, or 1.0% by weight of cement (bwc). %, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 2.0%, or 5% bwc or less, and in certain embodiments at least 0.1% bwc, e.g., 0.1% to 0.5% bwc, preferably 0.1% to 0.4% bwc, and in certain embodiments at least 0.2% bwc, e.g., 0.2% to 0.5% bwc, preferably 0.3% to 0.5% bwc.

[0105] In embodiment 3, the present specification provides a method according to embodiment 1 or example 2, wherein the admixture comprises a dispersant, a water-reducing agent, an air-entraining agent, or a combination thereof.

[0106] In embodiment 4, the present disclosure provides a method according to any one of embodiments 1-3, wherein the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic acid ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate, or triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof.

[0107] In embodiment 5, the admixture herein may comprise at least 0.02%, 0.04%, 0.06%, 0.08%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, or 2.0% bwc, and / or 0.04%, 0.06%, 0.08%, 0.1%, 5. The method of any one of embodiments 1-4, wherein the soluble solids are present in an amount of 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 3.0%, 4.0%, or 5% bwc or less, and in certain embodiments, 0.05% to 1% bwc, e.g., 0.1% to 0.8% bwc.

[0108] In embodiment 6, the present disclosure provides a method according to any one of embodiments 1 to 5, wherein the admixture comprises a polycarboxylate or a polycarboxylic acid derivative.

[0109] In embodiment 7, the present disclosure provides a method according to embodiment 6, wherein the admixture comprises a polycarboxylic acid ether.

[0110] In embodiment 8, the present disclosure provides a method according to embodiment 7, wherein the polycarboxylate or polycarboxylic acid derivative is present in an amount of 0.1% to 1% bwc, preferably 0.2% to 1% bwc, and more preferably 0.2% to 0.8% bwc.

[0111] In embodiment 9, the present specification provides a method according to any one of embodiments 1 to 5, wherein the admixture comprises lignin or a lignin derivative.

[0112] In embodiment 10, the present disclosure provides a method according to embodiment 9, wherein the admixture comprises a lignosulfate, a lignosulfonate, or a combination thereof.

[0113] In embodiment 11, the present disclosure provides a method according to embodiment 9 or embodiment 10, wherein the admixture is present in an amount of 0.2% to 8% bwc, preferably 0.2% to 6% bwc, and more preferably 0.3% to 0.5% bwc.

[0114] In embodiment 12, the present disclosure provides a method according to any one of embodiments 1 to 5, wherein the admixture comprises a polyacrylate or a polyacrylic acid derivative.

[0115] In embodiment 13, the present disclosure provides a method according to embodiment 12, wherein the admixture is present in an amount of 0.02% to 0.3% bwc, preferably 0.04% to 0.2% bwc, and more preferably 0.06% to 0.2% bwc.

[0116] In embodiment 14, the present disclosure provides a method according to any one of the preceding embodiments, wherein combining carbon dioxide with an admixture results in a concrete mixture with an acceptable setting time, while an identical concrete mixture containing only the admixture and / or an identical concrete mixture containing only carbon dioxide results in a concrete mixture with an unacceptable setting time.

[0117] In embodiment 15, provided herein is a composition comprising: (i) hydraulic cement; (ii) water; (iii) carbon dioxide and / or a reaction product of carbon dioxide with the hydraulic cement in an amount between 0.01% and 5% bwc; and (iv) a mineral admixture in an amount between 0.01% and 2% bwc.

[0118] In embodiment 16, the present disclosure provides a composition according to embodiment 15, wherein the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic acid ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate, or triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof.

[0119] In embodiment 17, provided herein is the composition of embodiment 16, wherein the admixture comprises a polycarboxylate or polycarboxylic acid derivative.

[0120] In embodiment 18, provided herein is the composition of embodiment 17, wherein the admixture comprises a polycarboxylic ether.

[0121] In embodiment 19, we provide herein the composition of embodiment 18, wherein the polycarboxylate or polycarboxylic acid derivative is present in an amount of 0.1% to 1% bwc, preferably 0.2% to 1% bwc, and more preferably 0.2% to 0.8% bwc.

[0122] In embodiment 20, the present disclosure provides a composition according to embodiment 16, wherein the admixture comprises lignin or a lignin derivative.

[0123] In embodiment 21, provided herein is the composition of embodiment 20, wherein the admixture comprises a lignosulfate, a lignosulfonate, or a combination thereof.

[0124] In embodiment 22, the present disclosure provides a composition according to embodiment 20 or embodiment 21, wherein the admixture is present in an amount between 0.2% and 8% bwc, preferably between 0.2% and 6% bwc, and more preferably between 0.3% and 0.5% bwc.

[0125] In embodiment 23, provided herein is the composition of embodiment 16, wherein the admixture comprises a polyacrylate or a polyacrylic acid derivative.

[0126] In embodiment 24, the present disclosure provides a composition according to embodiment 23, wherein the admixture is present in an amount between 0.02% and 0.3% bwc, preferably between 0.04% and 0.2% bwc, and more preferably between 0.06% and 0.2% bwc.

[0127] In embodiment 25, provided herein is a method comprising adding one or more admixtures to water to form an admixture solution.

[0128] In embodiment 26, the present disclosure provides a method according to embodiment 25, wherein the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic acid ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate, triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof.

[0129] In embodiment 27, the present disclosure provides a method according to embodiment 26, wherein the admixture comprises a polycarboxylate or a polycarboxylic acid derivative.

[0130] In embodiment 28, the present specification provides a method according to embodiment 27, wherein the admixture comprises a polycarboxylic acid ether.

[0131] In embodiment 29, the present disclosure provides a method according to embodiment 28, wherein the polycarboxylate or polycarboxylic acid derivative is present in an amount of 10% to 80%, preferably 20% to 80%, and more preferably 20% to 60%.

[0132] In embodiment 30, the present disclosure provides a method according to embodiment 26, wherein the admixture comprises lignin or a lignin derivative.

[0133] In embodiment 31, the present disclosure provides a method according to embodiment 30, wherein the admixture comprises a lignosulfate, a lignosulfonate, or a combination thereof.

[0134] In embodiment 32, the present specification provides a method according to embodiment 30 or embodiment 31, wherein the admixture is present in an amount from 20% to 80%, preferably from 20% to 60%, and more preferably from 30% to 50%.

[0135] In embodiment 33, the present disclosure provides a method according to embodiment 26, wherein the admixture comprises a polyacrylate or a polyacrylic acid derivative.

[0136] In embodiment 34, the present disclosure provides a method according to embodiment 33, wherein the admixture is present in an amount of 2% to 30%, preferably 4% to 20%, and more preferably 6% to 20%.

[0137] In embodiment 35, the present specification provides a method according to any one of embodiments 25 to 34, wherein the water comprises potable water.

[0138] In embodiment 36, the present specification provides a method according to any one of embodiments 25 to 34, wherein the water comprises process water.

[0139] In embodiment 37, the present specification provides a method according to embodiment 36, wherein the water comprises process water, including wash water.

[0140] In embodiment 38, the present disclosure provides a method according to any one of embodiments 36-37, wherein the water comprises solids.

[0141] In embodiment 39, the present disclosure provides the method of embodiment 38, further comprising removing at least a portion of the solids before adding the one or more admixtures.

[0142] In embodiment 40, the present disclosure provides a method according to any one of embodiments 25 to 39, further comprising carbonating the water.

[0143] In embodiment 41, provided herein is a method according to embodiment 40, wherein the water is carbonated before adding one or more admixtures.

[0144] In embodiment 42, the present disclosure provides a method according to embodiment 40, wherein the water is carbonated after adding one or more admixtures.

[0145] In embodiment 43, the present disclosure provides a method according to any one of embodiments 25 to 42, further comprising adding the admixture solution to a composition comprising water, cement, carbon dioxide, and optionally aggregate and / or one or more additional admixtures.

[0146] In embodiment 44, provided herein is a method according to embodiment 43, wherein the carbon dioxide is combined with an admixture to obtain a concrete mixture having a higher compressive strength than an identical concrete mixture containing only the admixture and / or an identical concrete mixture containing only carbon dioxide at one or more times.

[0147] In embodiment 45, provided herein is a composition comprising one or more admixtures and water.

[0148] In embodiment 46, provided herein is a composition of embodiment 45, wherein the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic acid ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate, triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof.

[0149] In embodiment 47, provided herein is the composition of embodiment 46, wherein the admixture comprises a polycarboxylate or polycarboxylic acid derivative.

[0150] In embodiment 48, provided herein is the composition of embodiment 47, wherein the admixture comprises a polycarboxylic ether.

[0151] In embodiment 49, the present disclosure provides a composition according to embodiment 48, wherein the polycarboxylate or polycarboxylic acid derivative is present in an amount of 10% to 80%, preferably 20% to 80%, and more preferably 20% to 60%.

[0152] In embodiment 50, provided herein is the composition of embodiment 46, wherein the admixture comprises lignin or a lignin derivative.

[0153] In embodiment 51, provided herein is the composition of embodiment 50, wherein the admixture comprises a lignosulfate, a lignosulfonate, or a combination thereof.

[0154] In embodiment 52, the present specification provides a composition according to embodiment 50 or embodiment 51, wherein the admixture is present in an amount ranging from 20% to 80%, preferably from 20% to 60%, and more preferably from 30% to 50%.

[0155] In embodiment 53, provided herein is the composition of embodiment 46, wherein the admixture comprises a polyacrylate or a polyacrylic acid derivative.

[0156] In embodiment 54, the present disclosure provides a composition according to embodiment 53, wherein the admixture is present in an amount between 2% and 30%, preferably between 4% and 20%, and more preferably between 6% and 20%.

[0157] In embodiment 55, the present disclosure provides a composition according to any one of embodiments 45 to 54, wherein the water comprises potable water.

[0158] In embodiment 56, the present disclosure provides the composition of any one of embodiments 45-54, wherein the water comprises concrete recycled water.

[0159] In embodiment 57, the present disclosure provides the composition of embodiment 56, wherein the water comprises concrete reclamation water, including wash water.

[0160] In embodiment 58, the present disclosure provides a composition according to any one of embodiments 56-57, wherein the water comprises solids.

[0161] In embodiment 59, provided herein is the composition of embodiment 58, wherein at least a portion of the solids are removed prior to adding the one or more admixtures.

[0162] In embodiment 60, provided herein is a composition according to any one of embodiments 25 to 59, wherein the water is carbonated.

[0163] In embodiment 61, provided herein is a composition according to any one of embodiments 25 to 60, further comprising water, cement, carbon dioxide, and optionally aggregate and / or one or more additional admixtures.

[0164] In embodiment 62, provided herein is a composition according to embodiment 61, which is combined with carbon dioxide and an admixture to obtain a concrete mixture that, at one or more times, has a higher compressive strength than an identical concrete mixture containing only the admixture and / or an identical concrete mixture containing only carbon dioxide.

[0165] In embodiment 63, provided herein is an apparatus comprising: (A) a water source; (B) one or more admixture sources; and (C) a vessel to which the water source and the one or more admixture sources are operably connected.

[0166] In embodiment 64, the present specification provides an apparatus according to embodiment 63, wherein the apparatus is configured to combine water from the water source and one or more admixtures from the one or more admixture sources in the container.

[0167] In embodiment 65, the present specification provides an apparatus according to embodiment 63 or 64, further comprising (D) a gas source, and / or (E) a mixer configured to mix the water and the one or more admixture sources in the vessel.

[0168] In embodiment 66, the present specification provides the device described in embodiment 65, wherein the device further comprises: (i) a first conduit operably connected to the container at a proximal end, the first conduit through which the admixture solution flows from the proximal end through the first conduit and out at a distal end; and (ii) a second conduit located inside the first conduit, the second conduit operably connected to the gas source and configured to allow gas to flow in and out into the admixture solution in the first conduit.

[0169] In embodiment 67, provided herein is the device of embodiment 65 or 66, wherein the gas comprises carbon dioxide.

[0170] In embodiment 68, the present disclosure provides a device according to embodiment 66 or 67, wherein the diameter of the first conduit is 0.5 to 5 inches and the diameter of the second conduit is 0.3 to 3 inches.

[0171] In embodiment 69, the present specification provides an apparatus described in any one of embodiments 66 to 68, further comprising a control system including: (a) a sensor that senses a property of the admixture solution and transmits information regarding the property to a control unit; (b) the control unit that processes the information from the sensor; and (c) an actuator that receives a signal from the control unit based at least in part on the processed information from the sensor.

[0172] In Example 70, the present specification provides the apparatus of Example 69, wherein the characteristics include one or more of: (1) a pH of the admixture solution; (2) a rate at which carbon dioxide is supplied to the admixture solution; (3) a total volume of the admixture solution in the container; (4) a temperature of the admixture solution; (5) a specific gravity of the admixture solution; (6) a concentration of one or more ions in the admixture solution; (7) an age of the admixture solution; (8) a circulation rate of the admixture solution; (9) a timing of circulation of the admixture solution; (10) an appearance of bubbles on the surface of the admixture solution; (11) a carbon dioxide concentration in the air above the admixture solution; (12) an electrical conductivity of the admixture solution; (13) an optical property of the admixture solution; and (14) an amount of admixture added to the admixture solution.

[0173] In embodiment 71, the present specification provides an apparatus described in embodiment 69 or 70, wherein the control unit includes at least two sensors, and the sensors are configured to monitor at least two characteristics.

[0174] In embodiment 72, the present specification provides an apparatus described in embodiment 69 or 70, wherein the control unit includes at least three sensors, and the sensors are configured to monitor at least three characteristics.

[0175] In embodiment 73, the present specification provides an apparatus described in embodiment 69 or 70, wherein the control unit includes at least four sensors, and the sensors are configured to monitor at least four characteristics.

[0176] In embodiment 74, the present specification provides an apparatus described in embodiment 69 or 70, wherein the control unit includes at least five sensors, and the sensors are configured to monitor at least five characteristics.

[0177] In embodiment 75, the present disclosure provides an apparatus according to any one of embodiments 63 to 74, wherein the water source comprises potable water.

[0178] In embodiment 76, the present disclosure provides an apparatus according to any one of embodiments 63-74, wherein the water source comprises concrete reclaimed water.

[0179] In embodiment 77, the present specification provides an apparatus according to embodiment 76, wherein the concrete reclaimed water comprises wash water.

[0180] In embodiment 78, provided herein is an apparatus according to embodiment 76 or 77, wherein the container comprises a reclaimer.

[0181] In embodiment 79, the present specification provides an apparatus according to embodiment 76 or 77, wherein the container is operably connected to a reclaimer.

[0182] In embodiment 80, the present specification provides an apparatus according to any one of embodiments 76 to 79, wherein the apparatus is configured to remove at least a portion of solids from the concrete reclaimed water. [Example]

[0183] Example 1 Unless otherwise stated, the following protocols are used in the examples.

[0184] Weighed out 150g of cement and 150g of water. Divided the admixture into syringes as needed. Divided solid CO2 into desired dosages as needed.

[0185] Water was poured into a container (e.g., a 1 liter bottle) followed by the cement. Where appropriate, the admixture was added to the SodaStream bottle using a syringe.

[0186] The contents were mixed in a vortex blender for 2 minutes.

[0187] CO2 was added and mixed for an additional 2 minutes.

[0188] Approximately 100 g of the mixture was poured into a calorimeter cup and secured with a lid. The sample was placed in an isothermal calorimeter and the energy release was recorded for a minimum of 20 hours.

[0189] The CO2 dosages used were 0.05%, 0.1%, 0.2%, 0.3%, and 0.4% CO2 by mass of cement. The 0.1% dosage was 0.15 g of solid CO2 flakes.

[0190] Calculations of reactivity were performed for the remaining test series using controls containing the same admixtures, when available.

[0191] The compositions and properties of the cements used in the examples are shown in the table below.

[0192] [Table 3]

[0193] Example 2 This was an example of a cement response calculation. Figures 1-3 each show a power law curve, an energy curve highlighting the energy at 16 hours, and a plot of energy at 15 hours versus CO2 input. The slope through each point can be interpreted as the reactivity of the cement + CO2 system. A higher slope indicated a more reactive cement.

[0194] Example 3 In this example, Exshaw GUL cement was used with various CO2 inputs and without admixtures.

[0195] Figures 4-6 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using the 20 hour data = 0

[0196] This example confirms that this type of cement is relatively unreactive with carbon dioxide alone, at least at low dosages.

[0197] Example 4 In this example, the same cement as in Example 3 was used with various CO2 inputs, and an admixture (PAANa, sodium polyacrylate), 0.08% dispersant.

[0198] 7-9 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using the 20 hour data = 7.

[0199] This example shows that the combination of carbon dioxide and admixtures when using a sodium polyacrylate dispersion results in higher energy release (e.g., assumed to be proportional to the compressive strength achieved) at all carbon dioxide dosages, and confirms that a plateau is reached at carbon dioxide dosages of 0.2% and above.

[0200] Example 5 In this example, the same cement as in Example 3 was used with various CO2 inputs, as well as an admixture (PAANa, sodium polyacrylate), and 0.16% dispersant.

[0201] 10-12 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 176

[0202] This example shows that the combination of carbon dioxide and admixture when using a higher dosage of sodium polyacrylate dispersion than in the previous examples results in a higher energy release (e.g., assumed to be proportional to the compressive strength achieved) compared to the control at all carbon dioxide inputs, with a peak at 0.3% carbon dioxide that is over 100% higher than the control.

[0203] Example 6 In this example, the same cement as in Example 3 was used with various CO2 inputs and an admixture, GCP Zyla 610, 0.2% polycarboxylic ether (PCE) water reducer.

[0204] 13-15 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 52

[0205] This example shows that a higher amount of carbon dioxide, 0.3% or 0.4%, is required to achieve a higher energy release when using a PCE-based water reducer in combination with admixtures compared to the control.

[0206] Example 7 In this example, the same cement as in Example 3 was used with various CO2 inputs and an admixture, GCP Zyla 610, a 0.8% polycarboxylic acid ether (PCE) water reducer.

[0207] 16-18 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 76

[0208] This example confirms that the combination of carbon dioxide and admixture when using higher dosages of PCE-based water reducer than in the previous examples shows similar energy release to the control at low dosages (0.05% and 0.1%) and greater energy release at higher dosages (0.2%, 0.3%, and 0.4%).

[0209] Example 8 In this example, National Lebec Type IL cement was used with various CO2 inputs and without admixtures.

[0210] 19-21 show the power curve, the energy curve, and the plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using the 20 hour data = -10

[0211] This example shows cement types that either do not react with carbon dioxide alone or show slightly lower energy release than the control at all dosages.

[0212] Example 9 In this example, the same cement as in Example 8 was used with various CO2 inputs and an admixture, 0.385% Euclid Plastol 6400, a polycarboxylic ether (PCE) based superplasticizer.

[0213] 22-24 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 25

[0214] This example confirms that the combination of carbon dioxide and admixture when using a PCE-based superplasticizer shows similar energy release to the control at low dosages (0.05%) and greater energy release at higher dosages (0.1%, 0.2%, 0.3%, and 0.4%).

[0215] Example 10 In this example, the same cement as in Example 8 was used with various CO2 inputs and an admixture, 0.385% Euclid Plastol 6400, a polycarboxylic ether (PCE) based superplasticizer.

[0216] 25-27 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 34

[0217] This example, as with the previous examples, confirms that the combination of carbon dioxide and admixture when using a PCE-based superplasticizer shows similar energy release to the control at low doses (0.05% and 1%), and greater energy release at higher doses (0.2%, 0.3%, and 0.4%). Example 10A

[0218] In this example, Monarch cement was used with various CO inputs and without admixtures. The reactivity of Monarch cement without admixtures was estimated to be 58 (data not shown).

[0219] Example 11 In this example, the same cement as in Example 8 was used with various CO2 inputs and admixtures, including 0.37% Sika Plastocrete 161, a lignin polymer-based water reducer.

[0220] 28-30 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 34

[0221] This example confirms that the combination of carbon dioxide and admixture with a lignin polymer-based water reducer still shows lower energy release than the control at low doses (0.05% and 1%), but shows greater energy release at higher doses (0.2%, 0.3%, and 0.4%).

[0222] Example 12 In this example, the same cement as in Example 8 was used with various CO2 inputs and admixtures, including 0.59% MasterPolyheed 997, a lignosulfonate triethanolamine-based medium-performance water reducer.

[0223] 31-33 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 182

[0224] This example confirms that, while the use of admixture alone results in less than two-thirds of the energy release of the control, the combination of carbon dioxide and admixture with a lignosulfonate triethanolamine-based medium-performance water reducer results in energy release close to that of the control at low dosages (0.05% and 1%) and greater at higher dosages (0.2%, 0.3%, and 0.4%). This example demonstrates the synergistic effect of admixture and carbon dioxide; carbon dioxide alone does not result in an increase in energy release (see Example 8), and the use of admixture alone significantly reduces energy release, but the combination of admixture and carbon dioxide significantly increases energy release as the amount of carbon dioxide added increases.

[0225] Example 13 In this example, the effects on setting time of using only the admixture and of using a combination of the admixture and carbon dioxide were examined.

[0226] The results are shown in Figure 34 (thermal index of setting time), which is defined in ASTM C1679 "Standard Practice for Measuring Hydration Kinetics of Hydraulic Cementitious Mixtures Using Isothermal Calorimetry" as the hydration time to reach 50% of the heat output of the maximum of the main hydration peak. The use of a water reducer caused a delay. Addition of CO2 brought the setting time back within the requirements (no more than 30 minutes faster and no more than 60 minutes slower than the standard value).

[0227] This example shows that adding carbon dioxide to an admixture that causes undesirable slow setting times can bring the setting time back within an acceptable range.

[0228] Example 14 In this example, the same cement as in Example 8 was used with various CO2 inputs and admixtures, including 0.39% Euclid Eucon WR, a lignosulfate-based water reducer.

[0229] Figures 34-37 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 158

[0230] This example confirms that when admixture is used alone, energy release is less than half that of the control, but that the combination of carbon dioxide and admixture when a lignosulfate-based water reducer is used achieves greater energy release, but does not reach that of the control even when the maximum amount of carbon dioxide is used. This example demonstrates the synergistic effect of admixture and carbon dioxide, confirming that carbon dioxide alone does not result in an increase in energy release (see Example 8), and that while admixture alone significantly reduces energy release, combining admixture and carbon dioxide significantly increases energy release with increasing carbon dioxide input.

[0231] Example 15 In this example, the same cement as in Example 8 was used with various CO2 inputs and admixtures, including 0.29% MasterGlenium 3030, a polycarboxylic acid ether (PCE)-based superplasticizer.

[0232] 38-40 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 77

[0233] In this example, the use of the admixture alone produced better results than without the admixture, but even better results were obtained by combining the admixture with carbon dioxide at dosages of 0.2% or greater.

[0234] Example 16 In this example, the same cement as in Example 8 was used with various CO2 inputs and an admixture, 0.49% Sika Viscocrete 1000, a polycarboxylic acid ether (PCE) based superplasticizer.

[0235] 41-43 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 84

[0236] In this example, it is confirmed that when admixture alone is used, the energy release is lower than the control, but when a polycarboxylic acid ether (PCE)-based superplasticizer is used, the combination of carbon dioxide and admixture achieves a greater energy release, but does not reach the control even when the maximum amount of carbon dioxide is used.

[0237] Example 17 In this example, the effects on setting time of using only the admixture and of using a combination of the admixture and carbon dioxide were examined.

[0238] The results are shown in Figure 44 (thermal index of setting time), which is defined in ASTM C1679 "Standard Practice for Measuring Hydration Kinetics of Hydraulic Cementitious Mixtures Using Isothermal Calorimetry" as the hydration time to reach 50% of the heat output of the maximum of the main hydration peak. The use of a water reducer caused a delay. Addition of CO2 brought the setting time back within the requirements (no more than 30 minutes faster and no more than 60 minutes slower than the standard value).

[0239] This example shows that adding carbon dioxide to an admixture that causes undesirable slow set times can bring the set time back within acceptable limits. In this example, a larger dose of carbon dioxide was required to bring the set time within acceptable limits.

[0240] Example 18 In this example, the same cement as in Example 8 was used with various CO2 inputs and admixtures, including 0.26% GCP Zyla 640, a polycarboxylic acid ether (PCE) water reducer.

[0241] Figures 45-47 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 58

[0242] In this example, when only the admixture is used, the energy release is lower than the control, and it is confirmed that the combination of carbon dioxide and admixture when a polycarboxylic acid ether (PCE)-based water reducer is used can achieve the same or greater energy release, but the effect depends on the dosage.

[0243] Example 19 In this example, the same cement as in Example 8 was used with various CO2 inputs and admixtures, including 0.20% SikaControl Air 160, an air entrainment agent.

[0244] 48-50 show the power curve, energy curve, and plot of energy vs. CO2 input at 20 hours, respectively. Reactivity score using 20 hour data = 65

[0245] This example confirms that when admixture alone is used, energy release is lower than the control, and that the combination of carbon dioxide and admixture when an air entrainment agent is used can achieve similar or greater energy release, but the effect is dose-dependent.

[0246] Example 20 In this example, the effect of the combination of carbon dioxide and an admixture on compressive strength on the 7th and 28th days was examined.

[0247] Case 1 Admixture Mapei KB1200 Day 7 Strength Measurements - Control = 10, CO2 = 10 Input amount CO2-0.2% CO2 results were 1% less than the control on day 7

[0248] Case studies Admixture Polychem 400NC Strength on days 7 and 28 Measurements - Control = 9, CO2 = 8 CO2 input -0.2% CO2 results were 5% greater than the control on day 7 and 6% greater than the control on day 28

[0249] Chemical properties of admixtures Mapei KB 1200 Medium-performance water-reducing agent 0% to 20% sodium nitrate 5% to 10% TEA 1% to 2.5% sodium thiocyanate

[0250] Mapei Polychem 400 NC Water reducing agent 2.5% to 5% TEA

[0251] The results are shown in Figures 51 and 52.

[0252] This example shows that the effect of carbon dioxide and admixtures can be admixture dependent, where a medium-performance water-reducing agent containing sodium nitrate (optional), TEA, and sodium thiocyanate in combination with carbon dioxide exhibits lower compressive strength than the control at least at 7 days, while a water-reducing agent containing only TEA in combination with carbon dioxide exhibits higher compressive strength than the control at both 7 and 28 days.

[0253] Example 21 In this example, the effect of varying water-to-cement ratios (0.6, 0.8, 1.0, and 1.2) and increasing CO2 dosage (0.05%, 0.1%, 0.2%, 0.3%, and 0.4% by weight of cement) on the reactivity of cementitious mixtures was investigated. Samples were run for 20 hours using isothermal calorimetry to measure the change in heat released upon CO2 introduction. The increase in heat correlates with increased hydration, which is believed to result in stronger concrete samples, i.e., increased compressive strength.

[0254] Cement, water, and water reducer were mixed on a vortex mixer for 2 minutes. The desired amount of solid CO2 was added, and the batch was mixed for an additional 2 minutes. CO2 reactivity was measured using isothermal calorimetry. The energy evolution curves for all CO2 inputs were compared at the 16-hour time point (see Figure 51), and the cumulative energy at that time point was calculated. These energy values ​​were then plotted against the CO2 input added to a given sample (see Figure 52), yielding an approximately linear relationship, with the slope of the best fit line passing through these data points being an indication of reactivity. The greater the slope, the more reactive the cement; conversely, if the line is completely horizontal, the cement is considered unreactive.

[0255] This example shows that there is a linear relationship between increasing the water-to-cement ratio and increasing CO2 reactivity (Figure 53). Furthermore, it can be seen that the more space available for the CO2 reaction, the greater the reaction and the higher the compressive strength of the concrete.

[0256] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the invention. It will be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention.

Claims

1. 1. A method for producing a cement mixture comprising mixing water, cement, carbon dioxide, an admixture, and optionally an aggregate, wherein the combination of the carbon dioxide and the admixture results in a concrete mixture that, at one or more times, has a greater compressive strength than an identical concrete mixture containing only the admixture and / or an identical concrete mixture containing only carbon dioxide.

2. The carbon dioxide may be at least 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.07%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1.0% by weight of cement (bwc), and / or 2. The method of claim 1, wherein the cellulose is present in an amount of no more than 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 2.0%, or 5% bwc, and in certain embodiments at least 0.1% bwc, such as from 0.1% to 0.5% bwc, preferably from 0.1% to 0.4% bwc, and in certain embodiments at least 0.2% bwc, such as from 0.2% to 0.5% bwc, preferably from 0.3% to 0.5% bwc.

3. 3. The method of claim 1 or 2, wherein the admixture comprises a dispersant, a water-reducing admixture, an air-entraining agent, or a combination thereof.

4. 4. The method of any one of claims 1 to 3, wherein the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof.

5. The admixture may be at least 0.02%, 0.04%, 0.06%, 0.08%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, or 2.0% bwc, and / or 0.04%, 0.06%, 0.08%, 0.1%, 0.15%, 5. The method of any one of claims 1 to 4, wherein the cellulose is present in an amount of up to 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 3.0%, 4.0%, or 5% bwc, and in certain embodiments, from 0.05% to 1% bwc, for example, from 0.1% to 0.8% bwc.

6. The method of any one of claims 1 to 5, wherein the admixture comprises a polycarboxylate or a polycarboxylic acid derivative.

7. The method of claim 6 , wherein the admixture comprises a polycarboxylic ether.

8. 8. The method of claim 7, wherein the polycarboxylate or polycarboxylic acid derivative is present in an amount of 0.1% to 1% bwc, preferably 0.2% to 1% bwc, more preferably 0.2% to 0.8%.

9. The method of any one of claims 1 to 5, wherein the admixture comprises lignin or a lignin derivative.

10. 10. The method of claim 9, wherein the admixture comprises a lignosulfate, a lignosulfonate, or a combination thereof.

11. 11. A method according to claim 9 or 10, wherein the admixture is present in an amount of from 0.2% to 8% bwc, preferably from 0.2% to 6% bwc, more preferably from 0.3% to 0.5% bwc.

12. The method of any one of claims 1 to 5, wherein the admixture comprises a polyacrylate or a polyacrylic acid derivative.

13. 13. The method of claim 12, wherein the admixture is present in an amount of 0.02% to 0.3% bwc, preferably 0.04% to 0.2% bwc, more preferably 0.06% to 0.2% bwc.

14. 14. The method of any one of claims 1 to 13, wherein combining carbon dioxide with the admixture results in a concrete mix with an acceptable setting time, whereas an identical concrete mix containing only the admixture and / or an identical concrete mix containing only carbon dioxide results in a concrete mix with an unacceptable setting time.

15. (i) a hydraulic cement; (ii) water; and (iii) carbon dioxide and / or reaction products of carbon dioxide with said hydraulic cement in an amount of 0.01% to 5% bwc; (iv) admixtures in an amount of 0.01% to 2% bwc; A composition comprising:

16. 16. The composition of claim 15, wherein the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof.

17. 17. The composition of claim 16, wherein the admixture comprises a polycarboxylate or a polycarboxylic acid derivative.

18. 20. The composition of claim 17, wherein the admixture comprises a polycarboxylic ether.

19. 19. The composition of claim 18, wherein the polycarboxylate or polycarboxylic acid derivative is present in an amount of 0.1% to 1% bwc, preferably 0.2% to 1% bwc, more preferably 0.2% to 0.8% bwc.

20. 17. The composition of claim 16, wherein the admixture comprises lignin or a lignin derivative.

21. 21. The composition of claim 20, wherein the admixture comprises a lignosulfate, a lignosulfonate, or a combination thereof.

22. 22. A composition according to claim 20 or 21, wherein the admixture is present in an amount such that it is present in a concentration of from 0.2% to 8% bwc, preferably from 0.2% to 6% bwc, more preferably from 0.3% to 0.5% bwc.

23. 17. The composition of claim 16, wherein the admixture comprises a polyacrylate or a polyacrylic acid derivative.

24. 24. The composition of claim 23, wherein the admixture is present in an amount of 0.02% to 0.3% bwc, preferably 0.04% to 0.2% bwc, more preferably 0.06% to 0.2% bwc.

25. A method comprising adding one or more admixtures to water to form an admixture solution.

26. 26. The method of claim 25, wherein the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof.

27. 27. The method of claim 26, wherein the admixture comprises a polycarboxylate or a polycarboxylic acid derivative.

28. 28. The method of claim 27, wherein the admixture comprises a polycarboxylic ether.

29. 29. The method of claim 28, wherein the polycarboxylate or polycarboxylic acid derivative is present in an amount of from 10% to 80%, preferably from 20% to 80%, more preferably from 20% to 60%.

30. 27. The method of claim 26, wherein the admixture comprises lignin or a lignin derivative.

31. 31. The method of claim 30, wherein the admixture comprises a lignosulfate, a lignosulfonate, or a combination thereof.

32. 32. The method of claim 30 or 31, wherein the admixture is present in an amount present at a concentration of from 20% to 80%, preferably from 20% to 60%, more preferably from 30% to 50%.

33. 27. The method of claim 26, wherein the admixture comprises a polyacrylate or a polyacrylic acid derivative.

34. 34. The method of claim 33, wherein the admixture is present in an amount of from 2% to 30%, preferably from 4% to 20%, more preferably from 6% to 20%.

35. The method of any one of claims 25 to 34, wherein the water comprises potable water.

36. The method of any one of claims 25 to 34, wherein the water comprises process water.

37. 37. The method of claim 36, wherein the water comprises process water, including wash water.

38. The method of any one of claims 36 to 37, wherein the water contains solids.

39. 39. The method of claim 38, further comprising removing at least a portion of said solids prior to adding said one or more admixtures.

40. 40. The method of any one of claims 25 to 39, further comprising carbonating the water.

41. 41. The method of claim 40, wherein the water is carbonated prior to adding one or more admixtures.

42. 41. The method of claim 40, wherein the water is carbonated after adding one or more admixtures.

43. 43. The method of any one of claims 25 to 42, further comprising adding the admixture solution to a composition comprising water, cement, carbon dioxide, and optionally aggregate and / or one or more additional admixtures.

44. 44. The method of claim 43, wherein the carbon dioxide and the admixture are combined to obtain a concrete mixture that, at one or more times, has a higher compressive strength than an identical concrete mixture containing only the admixture and / or an identical concrete mixture containing only the carbon dioxide.

45. A composition comprising one or more admixtures and water.

46. 46. ​​The composition of claim 45, wherein the admixture comprises a polyacrylate, such as sodium polyacrylate; a polycarboxylate, such as a polycarboxylic ether; a lignin, such as a lignin polymer, a lignosulfate, a lignosulfonate triethanolamine; triethanolamine (TEA); a nitrate, such as sodium nitrate; a thiocyanate, such as sodium thiocyanate; or a combination thereof.

47. 47. The composition of claim 46, wherein the admixture comprises a polycarboxylate or a polycarboxylic acid derivative.

48. 48. The composition of claim 47, wherein the admixture comprises a polycarboxylic ether.

49. 49. The composition of claim 48, wherein the polycarboxylate or polycarboxylic acid derivative is present in an amount of from 10% to 80%, preferably from 20% to 80%, more preferably from 20% to 60%.

50. 47. The composition of claim 46, wherein the admixture comprises lignin or a lignin derivative.

51. 51. The composition of claim 50, wherein the admixture comprises a lignosulfate, a lignosulfonate, or a combination thereof.

52. 52. A composition according to claim 50 or 51, wherein the admixture is present in an amount present at a concentration of from 20% to 80%, preferably from 20% to 60%, more preferably from 30% to 50%.

53. 47. The composition of claim 46, wherein the admixture comprises a polyacrylate or a polyacrylic acid derivative.

54. 54. The composition of claim 53, wherein the admixture is present in an amount of from 2% to 30%, preferably from 4% to 20%, more preferably from 6% to 20%.

55. 55. The composition of any one of claims 45 to 54, wherein the water comprises potable water.

56. The composition of any one of claims 45 to 54, wherein the water comprises concrete reclamation water.

57. 57. The composition of claim 56, wherein the water comprises concrete reclamation water, including wash water.

58. 58. The composition of any one of claims 56 to 57, wherein the water contains solids.

59. 60. The composition of claim 58, wherein at least a portion of the solids are removed prior to adding the one or more admixtures.

60. 60. The composition of any one of claims 25 to 59, wherein the water is carbonated.

61. 61. The composition of any one of claims 25 to 60, further comprising water, cement, carbon dioxide, and optionally aggregate and / or one or more additional admixtures.

62. 62. The composition of claim 61, wherein the carbon dioxide and the admixture are combined to obtain a concrete mixture that, at one or more times, has a higher compressive strength than an identical concrete mixture containing only the admixture and / or an identical concrete mixture containing only carbon dioxide.

63. (A) a water source; (B) one or more admixture sources; (C) a container; wherein the water source and the one or more admixture sources are operably connected to the vessel.

64. 64. The apparatus of claim 63, wherein the apparatus is configured to combine water from the water source and one or more admixtures from the one or more admixture sources in the vessel.

65. (D) a gas source, and / or (E) a mixer configured to mix the water and the one or more admixture sources in the vessel.

65. The apparatus of claim 63 or 64, further comprising:

66. The device comprises: (i) a first conduit operably connected to the container at a proximal end, the admixture solution flowing from the proximal end through the first conduit and exiting at a distal end; (ii) a second conduit located inside the first conduit, the second conduit operably connected to the gas source and configured to allow gas to flow in and out of the admixture solution within the first conduit; 66. The apparatus of claim 65, further comprising:

67. 67. The apparatus of claim 65 or 66, wherein the gas comprises carbon dioxide.

68. 68. The apparatus of claim 66 or 67, wherein the first conduit has a diameter of 0.5 to 5 inches and the second conduit has a diameter of 0.3 to 3 inches.

69. (a) a sensor that senses a property of the admixture solution and transmits information about the property to a control unit; (b) the control unit, which processes the information from the sensor; (c) an actuator that receives a signal from the controller based at least in part on the processed information from the sensor; 69. The apparatus of any one of claims 66 to 68, further comprising a control system comprising:

70. The characteristics are: (1) the pH of the admixture solution; (2) the rate at which carbon dioxide is supplied to the admixture solution; (3) the total volume of the admixture solution in the container; (4) the temperature of the admixture solution; (5) the specific gravity of the admixture solution; (6) the concentration of one or more ions in the admixture solution; (7) the age of the admixture solution; (8) the circulation speed of the admixture solution; (9) the timing of circulation of the admixture solution; (10) the appearance of bubbles on the surface of the admixture solution; (11) the carbon dioxide concentration in the air above the admixture solution; (12) the electrical conductivity of the admixture solution; (13) the optical properties of the admixture solution; and (14) Amount of admixture to be added to the admixture solution 70. The apparatus of claim 69, comprising one or more of:

71. 71. The apparatus of claim 69 or 70, wherein the control unit includes at least two sensors, the sensors configured to monitor at least two properties.

72. 71. The apparatus of claim 69 or 70, wherein the control unit includes at least three sensors, the sensors configured to monitor at least three properties.

73. 71. The apparatus of claim 69 or 70, wherein the control unit includes at least four sensors, the sensors configured to monitor at least four properties.

74. 71. The apparatus of claim 69 or 70, wherein the control unit includes at least five sensors, the sensors configured to monitor at least five properties.

75. 75. Apparatus according to any one of claims 63 to 74, wherein the water source comprises potable water.

76. 75. The apparatus of any one of claims 63 to 74, wherein the water source comprises concrete reclaimed water.

77. 77. The apparatus of claim 76, wherein the concrete reclaiming water comprises wash water.

78. 78. The apparatus of claim 76 or 77, wherein the container comprises a reclaimer.

79. 78. The apparatus of claim 76 or 77, wherein the container is operably connected to a reclaimer.

80. 80. The apparatus of any one of claims 76 to 79, wherein the apparatus is configured to remove at least a portion of solids from the concrete reclaimed water.

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