Dry mix and cement containing cellulose ether as a lubricating additive for roller-compressed concrete applications, and methods for using them.

Abstract

The present invention relates to low viscosity cellulose ethers (1 wt. % solids, 20C and 514s measured using a strain controlled rotational rheometer (e.g., ARES-G2™, TA Instruments). -1 The present invention provides a granular wet cement composition having a shear rate of 50-750 mPa·s), classified aggregate, and hydraulic cement, or an admixture therefor comprising cement, classified aggregate, and cellulose ether. The wet granular hydraulic cement composition behaves like an asphalt composition, has zero or near zero slump, high lubricity, and has 5% to less than 13% by weight water, or preferably greater than 5% to 10.5% by weight water, based on the total weight of the granular wet cement composition. The low viscosity cellulose ether allows for lubrication without impairing compaction and without causing air entrainment.

Description

[Technical Field]

[0001] The present invention relates to a dry mix composition for use in roller-compacted concrete (RCC), and a low-slump or zero-slump wet cement composition prepared therefrom, and a method for paving with the wet cement composition. More specifically, the present invention relates to a dry mix composition comprising hydraulic cement, aggregate such as sand, pulverized granular material such as limestone, and one or more cellulose ethers in an amount of 0.05 to 1.3% by weight, or preferably 0.08 to 1.1% by weight, based on the total weight of the dry mix composition, and a wet cement composition prepared from up to 13% by weight or up to 10.5% by weight of water based on the total weight of the dry mix composition and the granular wet cement composition exhibits a slump of less than 6 mm, or preferably less than 4.5 mm, using a stainless steel cone with a height of 80 mm, a top diameter of 40 mm, and a bottom diameter of 90 mm, and a steel rod stirrer with a diameter of 9.5 mm and a length of 266.7 mm, as determined according to ASTM C143 (2010).

[0002] Roller-compressed concrete (RCC) is a durable, low-cost paving technology that has been used for secondary roads. Unlike conventional concrete paving, RCC can be paved with asphalt paving equipment without the use of formwork, molds, or reinforcements. Reopening of RCC roads can be as fast as one day after paving, whereas conventional concrete paving may require several weeks of hardening before the road can be opened and used. RCC is a desirable option due to its easier paving process and rapid reopening, provided it can maintain a smooth appearance and the high durability characteristic of concrete paving. However, RCC has a higher volume of aggregate compared to conventional concrete, and the exposed surface of known RCC pavings has a high area fraction of exposed aggregate, making it rough and susceptible to rapid deterioration due to insufficient compression and strength loss after paving, limiting its use in parking lots, industrial roads, basements, and shoulders.

[0003] In known versions of RCC, compressibility and workability issues have been managed by the addition of chemical admixtures and optimization of the formulation. The term "compression" is defined as the act or result of densifying a material by removing air bubbles while maintaining its water content. However, when paving materials, applying pressure to compress the pavement can create an alternative pathway of "consolidation," in which case the material is densified by the removal of either voids or water. The removal of water can have detrimental effects on the pavement material, ultimately leading to breakage and loss of strength. Creating a water composition gradient by compressing only from the top surface can also be detrimental, as the reduced water level at the top negatively affects cement hardening, while excess water at the bottom can result in a layer that hardens in a swollen state. However, admixtures are designed to exist in the fluid or paste phase of the cement, which is itself limited to the RCC composition. Very high levels of admixtures are required to confirm the desired effects on compressibility and workability, making them prohibitively expensive and / or negatively affecting strength or workability. It is desirable to create an RCC-forming dry mix that allows for good compression without a high proportion of admixture components.

[0004] Bury et al., U.S. Patent No. 8,377,196(B2), discloses a dry-cast cementum composition of rheology-modifying additives comprising at least one shear-thickening additive A, such as cellulose ethers containing hydroxyalkylcellulose, carboxyalkylcellulose salts, carboxyalkylhydroxyalkylcellulose, hydroxyalkylhydroxyalkylcellulose, and mixtures thereof, and one non-shear-thickening additive B. The composition can enable improvements in cycle time, ease of finishing, compressive strength, and compression ratio. However, Bury et al.'s composition does not require a mold and does not exhibit sufficient viscosity to provide a composition that exhibits little to no slump when mixed, thus excluding its use in any compressed concrete pavement solution.

[0005] According to the present invention, the inventors have solved the problem of providing a dry mix that provides a wet cement composition that exhibits good compression, shows little to no slump, and is suitable for use in, for example, roller compression or paving methods. [Overview of the project]

[0006] According to the present invention, the dry mix composition is as follows: A dry mix composition comprising 10 to 23% by weight, preferably 12 to 20% by weight, of hydraulic cement, such as ordinary Portland cement, alumina cement, fly ash, pozzolanic acid, and mixtures thereof, and a dry mix composition comprising 70 to 89.95% by weight, preferably 75 to 89.65% by weight, of classified aggregate, wherein the classified aggregate is i) One or more coarse aggregates having a sieve size of 500 microns to 20 mm, or preferably 1 to 18 mm, for example, sand, limestone, gravel, granite, or clay, or preferably sand or gravel, or preferably a combination of a first coarse aggregate and a second coarse aggregate, wherein the first coarse aggregate has a sieve size of 200 microns to 3000 microns, the second coarse aggregate has a sieve size of 2000 microns to 20 mm, and the ratio of the sieve size of the second coarse aggregate to the sieve size of the first coarse aggregate is in the range of 15:1 to 1.5:1, or preferably 10:1 to 2:1, and ii) Classified aggregate comprising one or more fine aggregates having a sieve particle size of 40 to less than 3000 microns, or preferably 70 to 3000 microns, preferably limestone or sand, A cellulose ether composition comprising 0.05 to 1.3% by weight, preferably 0.08 to 1.1% by weight, or more preferably 0.08% to 0.35% by weight, of one cellulose ether or a mixture of two or more cellulose ethers, based on the total weight of the dry mix composition, wherein the cellulose ether or mixture of two or more cellulose ethers has a cellulose ether solids content of 1% by weight, as determined by using a strain-controlled rotational rheometer (preferably ARES-G2®, TA Instruments, New Castle, DE) equipped with a DIN (Deutsches Institut fur Normung eVin German meaning German Institute for Standardization) sample holder with a Peltier temperature controller, TRIOS® data acquisition software (TA Instruments), and a concentric cylinder, and using a strain rate sweep of 0.03 to 300 / s at 10 points / decade, and reporting the average of two tests for each cellulose ether composition, at 20°C, 514s. -1 Shear rate of 50-750 mPa * s, or preferably 80-500 MPa * The aqueous solution has a viscosity in the range of s, and the aqueous solution comprises a cellulose ether composition prepared by drying cellulose ether powder overnight in a vacuum oven at 70°C, dispersing it in hot water at 70°C, dissolving it while cooling to room temperature with stirring, and refrigerating it at 4°C overnight. The weight ratio of total coarse aggregate to total fine aggregate in the classified aggregate is in the range of 4:1 to 0.9:1, or preferably 3:1 to 1:1. Furthermore, the sum of all weight percentages equals 100%. The dry mix composition according to the present invention may further contain one or more superplasticizers selected from polycarboxylate ether-containing superplasticizers, naphthalene sulfonate-containing superplasticizers, lignosulfonate-containing superplasticizers, or mixtures thereof, preferably a polycarboxylate ether-containing superplasticizer.

[0007] In the dry mix composition according to the present invention, the hydraulic cement may be ordinary Portland cement, aluminate cement, pozzolann, or a mixture thereof, or preferably selected from ordinary Portland cement, aluminate cement, or a mixture thereof.

[0008] Preferably, in the classified aggregate of the dry mix composition according to the present invention, the ratio of the sieve size of the total coarse aggregate to the sieve size of the fine aggregate is in the range of 10:1 to 2:1, or preferably 8:1 to 2:1.

[0009] More preferably, the dry mix composition according to the present invention comprises a mixture of a first coarse aggregate, such as sand or gravel having a sieve size of 300 microns to 2000 microns, and a second coarse aggregate, such as gravel or stone having a sieve size of 2000 microns to 18 mm, as the coarse aggregate in the classified aggregate, wherein the ratio of the sieve size of the second coarse aggregate to the sieve size of the first aggregate is in the range of 15:1 to 1.5:1, or preferably 10:1 to 2:1.

[0010] In the dry mix composition according to the present invention, at least one of the one or more cellulose ethers has a side chain selected from hydroxyethyl, hydroxypropyl, methyl, and combinations thereof, or preferably a side chain selected from hydroxyethyl and methyl. More specifically, at least one of the one or more cellulose ethers is a hydroxyethylmethylcellulose ether having a hydroxyethyl content (MS) in the range of 0 to 0.4 and a methoxyl content (DS) of 1.2 to 1.8, or a hydroxyethylcellulose having a hydroxyethyl content (MS) of 1.4 to 2.4, or preferably 1.8 to 2.2.

[0011] In the dry mix composition according to the present invention, the superplasticizer, if present, may be used in the form of 0.1 to 0.5% by weight of polycarboxylate ether, 0.2 to 5.0% by weight or 0.3 to 1.0% by weight of naphthalene sulfonate or lignosulfonate-containing material, preferably in the form of 0.1 to 0.5% by weight of polycarboxylate ether.

[0012] Preferably, the dry mix composition according to the present invention contains less than 2% by weight of cellulose ether + superplasticizer, based on the total weight of the dry mix composition.

[0013] The present invention provides a granular wet cement composition according to a second aspect of the present invention, in which the dry mix composition is mixed with a separate component of water in an amount of 5.0 to 13.0% by weight, or preferably more than 5.0 to 10.5% by weight, based on the total weight of the composition obtained, the composition is mixed in a plastic bag, the powder is added to the indicated amount of water in a Hobart mixing bowl, the mixture is mixed twice at speed 1 for 15 seconds, stopping after each mix and rubbing the sides of the bowl, the mixture is allowed to stand for 10 minutes, and the mixture is placed in three equal layers through a water-moistened stainless steel cone (height 80m) via a sponge. Pouring into a cone (with a top diameter of 40 mm and a bottom diameter of 90 mm), placing it on a non-absorbent surface, filling each layer, mixing by moving a stainless steel rod (preferably 266.7 mm in length and 9.5 mm in diameter) in a circular motion, positioning the rod parallel to the side of the cone, moving it to a vertical position and finishing in the center, finishing the surface of the wet cement composition to be coplanar with the top of the cone, lifting the cone away from the wet cement composition, measuring the total height of the cone, and reporting a slump of less than 30 seconds by recording the difference between the measured height and 80 mm as less than 6 mm, or preferably less than 4.5 mm, thereby having a slump as determined in accordance with ASTM C143 (2010).

[0014] The dry mix composition according to the present invention may contain one component of a two-component composition, wherein the first component contains the dry mix composition, the second component contains water, and either the first or second component contains one or more cellulose ethers and, if used, one or more superplasticizers.

[0015] In a second aspect of the present invention, the dry mix composition and the granular wet cement composition from water are Based on the total weight of the dry mix composition, 10 to 23% by weight, or preferably 12 to 20% by weight, of hydraulic cement, such as pozzolann, ordinary Portland cement, aluminate cement, fly ash, and mixtures thereof, Based on the total weight of the dry mix composition, the classified aggregate is in an amount of 70-89.95% by weight, or preferably 75-89.65% by weight, wherein the classified aggregate is i) One or more coarse aggregates having a sieve size of 200 microns to 20 mm, for example, sand, limestone, gravel, granite, or clay, or preferably sand, or more preferably a combination of a first coarse aggregate and a second coarse aggregate, wherein the first coarse aggregate has a sieve size of 200 microns to 3000 microns, the second coarse aggregate has a sieve size of 2000 microns to 20 mm, and the ratio of the sieve size of the second coarse aggregate to the sieve size of the first coarse aggregate is in the range of 15:1 to 1.5:1, or preferably 10:1 to 2:1, and ii) Classified aggregate comprising one or more fine aggregates, preferably limestone, having a sieve particle size of 40 microns to 3000 microns, or preferably 70 microns to 3000 microns, An amount of cellulose ether or a mixture of two or more cellulose ethers of 0.05 to 1.3% by weight, or preferably 0.08 to 1.1% by weight, or more preferably 0.08% to 0.35% by weight, wherein the cellulose ether or the mixture of two or more cellulose ethers is determined using a strain-controlled rotational rheometer (preferably, an ARES-G2 (trademark), TA Instruments, New Castle, DE equipped with a Peltier temperature controller, TRIOS (trademark) data collection software (TA Instruments) and a DIN (Deutsches Institut fur Normung e.V. in German meaning German Institute for Standardization) sample fixture with concentric cylinders) with a strain rate sweep of 0.03 to 300 / s at 10 points / decade, and is represented as the average of two tests for each cellulose ether, at 1% by weight cellulose ether solids content, 20 °C, 514 s -1 Has an aqueous solution viscosity in the range of 50 to 650 mPa·s, or preferably 80 to 500 mPa·s, at a shear rate, and the aqueous solution is prepared by drying the powder of the cellulose ether in a vacuum oven at 70 °C overnight, dispersing it in hot water at 70 °C, dissolving it while cooling to room temperature with stirring, and refrigerating it at 4 °C overnight, and contains, based on the total weight of the cellulose ether or the mixture of two or more cellulose ethers and the granular wet cement composition, an amount of water of 5.0 to 13.0% by weight, or preferably more than 5.0% to 10.5% by weight The wet cement composition has a water saturation level of less than 58%, or preferably 56.5% or less, as defined by the percentage of voids filled with wet cement or cement + water, as represented by the following formula Water saturation = (V w + V c ) / V V , wherein V w is the volume of water in the wet cement composition, V c is the volume of cement, and V c = m c / ρc And in the formula, m c ρ is the mass of cement in the wet cement composition, c V is the material density of cement. V The particle density ρ of each material other than cement and water is shown. i Measure the total mass of each material other than cement and water m i Measure the total volume V of all materials other than cement and water, mix them thoroughly, pour them all into a container, and measure the void volume V v =V-Σ(m i / ρ i This is the total void volume in the total mixture, which is determined by calculating the total void volume in the total mixture. Furthermore, the weight ratio of total coarse aggregate to total fine aggregate in the classified aggregate is in the range of 4:1 to 0.9:1, or preferably 3:1 to 1:1. Furthermore, the total weight percentages of all components in the dry mix composition add up to 100%.

[0016] According to the granular wet cement composition of the present invention, the ratio of the sieve size of the total coarse aggregate to the sieve size of the fine aggregate may be in the range of 20:1 to 1.5:1, or preferably 10:1 to 2:1.

[0017] More preferably, the granular wet cement composition according to the second aspect of the present invention comprises a mixture of a first coarse aggregate, such as sand or gravel having a sieve size of 300 to 3000 microns, and a second coarse aggregate, such as gravel or stone having a sieve size of 2000 microns to 18 mm, as the coarse aggregate in the classified aggregate, wherein the ratio of the sieve size of the second coarse aggregate to the sieve size of the first coarse aggregate is in the range of 15:1 to 1.5:1, or preferably 10:1 to 2:1.

[0018] According to a granular wet cement composition of a second aspect of the present invention, the wet cement composition may comprise a mixture of two components, the first component comprising a dry mix composition and the second component comprising water, and either the first or second component comprising one or more cellulose ethers in the amount described for the dry mix composition and, if used, one or more superplasticizers in the amount described for the dry mix composition.

[0019] A granular wet cement composition according to a second aspect of the present invention may further contain one or more superplasticizers selected from polycarboxylate ether-containing superplasticizers, naphthalene sulfonate-containing superplasticizers, lignosulfonate-containing superplasticizers, or mixtures thereof.

[0020] In a granular wet cement composition according to a second aspect of the present invention, the superplasticizer may be used in an amount of 0.1 to 0.5% by weight of a polycarboxylate ether-containing material, 0.2 to 5.0% by weight or 0.3 to 1.0% by weight of a naphthalene sulfonate-containing material or a lignosulfonate-containing material, preferably 0.1 to 0.5% by weight of a polycarboxylate ether-containing material, all amounts being based on the total weight of the dry mix composition.

[0021] A granular wet cement composition according to a second aspect of the present invention further comprises, as part of a first component as a dry mix composition, one or more superplasticizers selected from polycarboxylate ether-containing superplasticizers, naphthalene sulfonate-containing superplasticizers, lignosulfonate-containing superplasticizers, or mixtures thereof.

[0022] A granular wet cement composition according to a second aspect of the present invention may further contain, as part of a dry mix composition to be mixed with water, one or more superplasticizers selected from polycarboxylate ether-containing superplasticizers, naphthalene sulfonate-containing superplasticizers, lignosulfonate-containing superplasticizers, or mixtures thereof.

[0023] Preferably, the granular wet cement composition according to the second aspect of the present invention is prepared using a stainless steel cone with a height of 80 mm, a top diameter of 40 mm, and a bottom diameter of 90 mm, preferably using a steel rod stirrer with a diameter of 9.5 mm and a length of 266.7 mm, by mixing the dry mix in a plastic bag, adding the powder to the indicated amount of water in a Hobart mixing bowl, mixing twice at speed 1 for 15 seconds, stopping after each mix and scraping the sides of the bowl, allowing the mixture to slosh for 10 minutes, pouring the mixture in three equal layers into a water-moistened stainless steel cone via a sponge, placing it on a non-absorbent surface, filling each layer, mixing by moving a stainless steel rod in a circular motion, positioning the rod parallel to the sides of the cone, moving it to a vertical position and finishing in the center, finishing the surface of the wet cement composition to be flush with the top of the cone, lifting the cone away from the wet cement composition, measuring the total height of the cone, and reporting a slump of 30 seconds or less by recording the difference between the measured height and 80 mm as 6 mm or less, or more preferably 4.5 mm or less. It has a slump as determined according to C143(2010).

[0024] More preferably, the wet cement composition according to the second aspect of the present invention has a lubricity of 22° to 36.8° or less, or preferably 26° to 36°, or 36.0° or less, which is determined as the angle of slope of the yield curve of the normal stress at which the composition yields in a shear test plotted against the normal stress (on a horizontal coordinate) measured at a point interval of 5 points / decade of the percentage of the pre-shear normal stress, in accordance with ASTM D6773-16 (2016), preferably using an automated shear testing machine controlled by the software RSTCONTROL95 for MS Windows (Dietmar Schulze, Wolfenbuttel, DE), with 50,000 Pa as the pre-shear normal stress, and then decreasing the normal stress over a normal stress range of 12,500 Pa to at least 40,000 Pa, with measurements taken at a point interval of 5 points / decade of the percentage of the pre-shear normal stress.

[0025] In a third aspect of the present invention, a method for producing and using a granular wet cement composition according to a second aspect of the present invention includes: mixing water, hydraulic cement, and classified aggregate to form a wet cement composition; adding a cellulose ether composition and an optional superplasticizer as dry powders thereto and mixing them in a pump or Pugmill mixer to form a granular wet cement composition; applying the granular wet cement composition to a substrate without molds or formwork; and then paving or rolling the wet cement composition to form a concrete or cement layer such as a road or pavement. Paving or rolling can preferably be carried out without heat, without steam, using a steam roller, or using a conventional asphalt paving apparatus.

[0026] In a third aspect of the present invention, the granular wet cement composition comprises water and a dry mix composition, wherein the dry mix composition is Based on the total weight of the dry mix composition, 10 to 23% by weight, or preferably 12 to 20% by weight, of hydraulic cement, such as pozzolann, ordinary Portland cement, aluminate cement, fly ash, and mixtures thereof, Based on the total weight of the dry mix composition, the classified aggregate is in an amount of 70-89.95% by weight, or preferably 75-89.65% by weight, wherein the classified aggregate is i) One or more coarse aggregates having a sieve size of 200 microns to 20 mm, for example, sand, limestone, gravel, granite, or clay, or preferably sand, or more preferably a combination of a first coarse aggregate and a second coarse aggregate, wherein the first coarse aggregate has a sieve size of 200 microns to 3000 microns, the second coarse aggregate has a sieve size of 2000 microns to 20 mm, and the ratio of the sieve size of the second coarse aggregate to the sieve size of the first coarse aggregate is in the range of 15:1 to 1.5:1, or preferably 10:1 to 2:1, and ii) Classified aggregate comprising one or more fine aggregates, preferably limestone, having a sieve particle size of 40 microns to less than 3000 microns, or preferably 70 microns to 3000 microns, Based on the total weight of the dry mix composition, the amount of cellulose ether or a mixture of two or more cellulose ethers is 0.05 to 1.3% by weight, preferably 0.08 to 1.1% by weight, or more preferably 0.08% to 0.35% by weight, expressed as the average of two tests for each cellulose ether, with a cellulose ether or mixture of two or more cellulose ethers having a 1% by weight cellulose ether solids content, expressed as the average of two tests at 20°C, 514s, determined using a strain-controlled rotational rheometer (ARES-G2®, TA Instruments, New Castle, DE) equipped with a Peltier temperature controller, TRIOS® data acquisition software (TA Instruments), and a DIN sample holder with a concentric cylinder, using a strain rate sweep of 0.03 to 300 / s at 10 points / decade. -1 The aqueous solution has a viscosity in the range of 50 to 650 m·Pas, or preferably 80 to 500 mPa·s, and the aqueous solution is a dry mix composition of cellulose ether or a mixture of two or more cellulose ethers, which is prepared by drying cellulose ether powder overnight in a vacuum oven at 70°C, dispersing it in hot water at 70°C, dissolving it while cooling to room temperature with stirring, and refrigerating it overnight at 4°C. Water is present in an amount of 5.0 to 13% by weight, or preferably more than 5 to 10.5% by weight, based on the total weight of the granular wet cement composition. Furthermore, the wet cement composition has a water saturation level of less than 58%, defined by the percentage of voids filled with wet cement, which is cement + water, as represented by the following formula: Water saturation = (V w +V c ) / V V , In the formula, V w V is the volume of water in the wet cement composition, c V is the volume of cement, c =mc / ρc, where mc is the mass of cement in the wet cement composition and ρc is the material density of cement, V V The particle density ρ of each material other than cement and water is shown.i Measure the total mass of each material other than cement and water m i Measure the total volume V of all materials other than cement and water, mix them thoroughly, pour them all into a container, and measure the void volume V v =V-Σ(m i / ρ i This is the total void volume in the total mixture, which is determined by calculating the total void volume in the total mixture. Furthermore, the weight ratio of the total coarse aggregate to the total fine aggregate in the classified aggregate is in the range of 4:1 to 0.9:1, or preferably 3:1 to 1:1. Furthermore, the total weight percentages of all components in the dry mix composition add up to 100%. Preferably, according to a method of applying the wet cement composition of the third aspect of the present invention, the composition includes a mixture of low-sieve-grade material having a sieve size of 200 microns to 3000 microns as coarse aggregate in the classified aggregate, and high-sieve-grade aggregate such as sand or gravel having a sieve size of 500 microns to 20 mm, or preferably 1.5 to 18 mm.

[0027] The ratio of the sieve size of the total coarse aggregate to the sieve size of the fine aggregate in the wet cement composition may be in the range of 20:1 to 1.5:1, or preferably 10:1 to 2:1.

[0028] According to a method of applying a wet cement composition according to a third aspect of the present invention, the wet cement composition comprises a mixture of two components, the first component comprising a dry mix composition containing or not containing one or more cellulose ethers, and, if used, one or more superplasticizers, the second component comprising water, and either the first or second component comprising the same amount of one or more cellulose ethers as described for the dry mix composition, and, if used, one or more superplasticizers as described for the dry mix composition. According to a method of applying a wet cement composition according to a third aspect of the present invention, the wet cement composition further comprises, as part of the first component, a dry mix composition to be mixed with water as the second component, or as a separate second component to be mixed with the dry mix composition as the first component as a solution or dispersion in water, one or more superplasticizers selected from polycarboxylate ether-containing superplasticizers, naphthalene sulfonate-containing superplasticizers, lignosulfonate-containing superplasticizers, or mixtures thereof.

[0029] In a method of applying a wet cement composition according to a third aspect of the present invention, the superplasticizer used in the wet cement composition is in the amount of 0.1 to 0.5% by weight of a polycarboxylate ether-containing material, 0.2 to 5.0% by weight or 0.3 to 1.0% by weight of a naphthalene sulfonate-containing material or lignosulfonate-containing material, or preferably 0.1 to 0.5% by weight of a polycarboxylate ether-containing material, all amounts being based on the total weight of the dry mix composition.

[0030] Preferably, according to the method of applying the wet cement composition of the third aspect of the present invention, the wet cement composition is prepared by mixing the dry mix in a plastic bag, adding the powder to the indicated amount of water in a Hobart mixing bowl, mixing twice at speed 1 for 15 seconds each time, stopping after each mixing to scrape the sides of the bowl, allowing the mixture to slosh for 10 minutes, pouring the mixture in three equal layers into a water-moistened stainless steel cone via a sponge, placing it on a non-absorbent surface, filling each layer, mixing by moving a stainless steel rod in a circular motion, positioning the rod parallel to the sides of the cone, moving it to a vertical position to finish in the center, finishing the surface of the wet cement composition to be coplanar with the top of the cone, lifting the cone away from the wet cement composition, measuring the total height of the cone, and reporting a slump of less than 30 seconds by recording the difference between the measured height and 80 mm as less than 6 mm, or preferably less than 4.5 mm, using a stainless steel cone with a height of 80 mm, a top diameter of 40 mm, and a bottom diameter of 90 mm, preferably a steel rod stirrer with a diameter of 9.5 mm and a length of 266.7 mm. It has a slump as determined according to C143(2010).

[0031] More preferably, according to a method of applying the wet cement composition of the third aspect of the present invention, the wet cement composition has a lubricity of 22° to 36.8° or less, or preferably 26° to 36°, or 36.0° or less, determined as the angle of slope of the yield curve taken as the level of normal stress at which the composition yields in a shear test plotted against the normal stress (on a horizontal coordinate system), measured at point intervals of 5 points / decade of the percentage of the preliminary shear normal stress, with 50,000 Pa as the preliminary shear normal stress, and then decreasing the normal stress over a normal stress range of 12,500 Pa to at least 40,000 Pa, with measurements taken at point intervals of 5 points / decade of the percentage of the preliminary shear normal stress.

[0032] The singular terms "a," "an," and "the" include plural referents unless the context makes it clear otherwise. Unless otherwise specified, terms used herein have the same meaning as those generally understood by those skilled in the art.

[0033] Unless otherwise specified, terms containing parentheses refer, alternatively, to the entire term as if the parentheses were absent, the same term without parentheses, and any combination of each alternative. Thus, the term "(meth)acrylate" alternatively includes methacrylate, acrylate, or mixtures thereof.

[0034] Endpoints in all ranges covering the same component or characteristic include the endpoint and can be combined independently. Therefore, for example, the disclosed range of 1.5:1 to 4.5:1, or preferably 2:1 to 4:1, or more preferably 2.5:1 to 3.7:1 means any or all of the ranges of 1.5:1 to 4.5:1, or 1.5:1 to 2:1, or 1.5:1 to 2.5:1, or 1.5:1 to 3.7:1, or 1.5:1 to 4:1, or 2:1 to 4.5:1, or preferably 2:1 to 2.5:1, or preferably 2:1 to 3.7:1, or preferably 2:1 to 4:1, or preferably 2.5:1 to 4:1, or more preferably 2.5:1 to 3.7:1.

[0035] Unless otherwise specified, the temperature and pressure conditions are room temperature (23°C) and standard pressure (101.3 kPa), also known as "ambient conditions." In addition, unless otherwise specified, all conditions include 50% relative humidity (RH).

[0036] All cited ranges are comprehensive and combinable. For example, the disclosure of 0.25–0.5% by weight, or preferably 0.35–0.45% by weight, includes all of the following: 0.25–0.5% by weight, or preferably 0.35–0.45% by weight, or 0.25–0.35% by weight, or 0.25–0.45% by weight, or 0.35–0.5% by weight, or 0.45–0.5% by weight.

[0037] As used herein, the terms "acrylic or vinyl" refer to addition polymerizable monomers or addition polymers of α,β-ethylenically unsaturated monomers, such as alkyl and hydroxyalkyl (meth)acrylates, vinyl ethers, ethylenically unsaturated carboxylic acids, alkyl (meth)acrylamides, or monomers containing oxyalkylene chain groups, such as methoxy poly(ethylene glycol)(meth)acrylate (mPEG(M)A) or poly(ethylene glycol)(meth)acrylate (PEG(M)A) and allyl poly(ethylene glycol) (APEG).

[0038] As used herein, the term “aqueous” means that the continuous phase or medium is water and a water-miscible compound in an amount of 0 to 10% by weight based on the weight of the medium. Preferably, “aqueous” means water.

[0039] As used herein, the term "ASTM" refers to the publications of ASTM International, West Conshohocken, PA.

[0040] As used herein, the term "hydraulic cement" includes substances that solidify and harden in the presence of water, such as Portland cement, silicate-containing cement, aluminate-based or alumina cement, pozzolanic cement, and composite cement.

[0041] As used herein, the terms “dry mixture” or “dry powder” mean a storage-stable powder containing cement, cellulose ether, any other polymer additives, and any fillers and dry additives. The dry mixture is free of water; therefore, it is storage-stable.

[0042] As used herein, the term "DS" refers to the average number of alkyl-substituted OH groups per anhydrous glucose unit in cellulose ether, as determined by the Zeisel method, and the term "MS" refers to the average number of hydroxyalkyl-substituted OH groups per anhydrous glucose unit. The term "Zeisel method" refers to the Zeisel cleavage procedure for determining MS and DS; see G. Bartelmus and R. Ketterer, Fresenius Zeitschrift fuer Analytische Chemie, Vol. 286 (1977, Springer, Berlin, DE), pages 161 to 190.

[0043] As used herein, the term “lubricity” refers to the slope of the yield curve, expressed as the angle of a linearized yield trajectory plot, measured by a shear test using an automated shear tester controlled by the software RSTCONTROL95 for MS Windows (Dietmar Schulze, Wolfenbuttel, DE), in accordance with ASTM D6773-16 (Standard Test Method for Bulk Solids Using Schulze Ring Shear Tester, 2016), with a given preliminary shear stress of 50,000 Pa. Lubricity measures the ability of particles to move relative to one another under shear, with lower relative normal forces and lower slopes indicating better lubricity. In other words, since internal friction is the ratio of the maximum internal shear force resisting the motion between particles of a material to the normal force (compression) between particles, or the resistance of particles moving relative to one another under compression and shear, a lower “internal friction” angle signifies higher lubricity.

[0044] As used herein, the term “overnight” means a period of 10 to 14 hours.

[0045] As used herein, the term “paste” refers to a mixture consisting of hydraulic cement and water, excluding aggregates.

[0046] As used herein, unless otherwise indicated, the term “polymer” includes both homopolymers and copolymers derived from two or more different monomers, as well as segmented copolymers and block copolymers.

[0047] As used herein, the term “sieve particle size” of a material refers to the particle size determined by successively sieving the material through progressively smaller mesh sieves until at least 10% by weight of the material is held on a given sieve, and recording the size of a sieve one sieve size larger than the first sieve that holds at least 10% by weight of the material.

[0048] As used herein, the term “total coarse aggregate sieve size” for a mixture of coarse aggregates means the weighted average of the sieve sizes of all coarse aggregates in the mixture. For example, the sieve size of a 50:50 w / w mixture of 1 mm sieve size coarse aggregate and 10 mm sieve size coarse aggregate is (1 mm × 0.5) + (10 mm × 0.5) or 5.5 mm.

[0049] As used herein, the term "slump" refers to the lateral or downward flow of a standing sample of a wet cement composition over a given period of time, which can be measured in several ways.

[0050] As used herein, the term “storage stability” means that, for a given powder additive composition, when left on a shelf at room temperature and standard pressure, the powder does not block after 5 days, or preferably after 10 days, and for a given aqueous composition, the liquid composition does not become cloudy, separate, or precipitate.

[0051] As used herein, the terms “total solids,” “solid,” or “as a solid” refer to the total amount of any or all of the nonvolatile components or materials present in a given composition, including synthetic polymers, monomers, natural polymers, acids, defoamers, hydraulic cements, fillers, inorganic materials, and additives such as other nonvolatile materials and initiators. Water, ammonia, and volatile solvents are not considered solids.

[0052] As used herein, the term "water saturation" is defined by the formula: Water saturation = (V w +V c ) / V V This refers to the result given by, in the formula, V w V is the volume of water in the wet cement composition, c V is the volume of cement, c =mc / ρc, where mc is the mass of cement in the wet cement composition and ρc is the material density of cement, V V The particle density ρ of each material other than cement and water is shown. i Measure the total mass of each material other than cement and water m i Measure the total volume V of all materials other than cement and water, mix them thoroughly, pour them all into a container, and measure the void volume V v =V-Σ(m i / ρ i The total void volume in the total mixture is determined by calculating the porosity or interparticle porosity ε = [V - Σ(m i / ρ i Also referred to as ) / V, it is the reciprocal of the "filling fraction" given by 1-ε. When used herein, unless otherwise indicated, the term "weight %" means weight percent based on the denominator shown.

[0053] According to the present invention, the inventors have discovered a granular hydraulic cement composition that behaves like an asphalt composition by using a low-viscosity cellulose ether in the cement admixture. The granular wet cement composition according to the present invention is slightly unsaturated in water and does not solidify or settle by its own weight, so it looks and behaves like mud. Similarly, wet cement compositions formed by mixing the dry mix composition according to the present invention with water and an admixture containing cellulose ether, do not solidify or settle by their own weight. The compositions of the present invention enable paving to achieve maximum strength via "compression" or volumetric compression without loss of wet cement material. The compositions provide viscosity that slows consolidation or loss of water and cement from the mass compared to compression. In addition, the compositions enable improved lubricity in the formulation, which facilitates the movement of aggregate particles necessary to compress, densify, and remove air bubbles to achieve optimal strength in the pavement. In particular, the inventors have discovered a lower viscosity cellulose ether or mixture thereof (1 wt% cellulose ether solids, 20°C, and 514s) in roller-compressed concrete (RCC). -1 Regarding the shear rate, using an ARES-G2™ strain-controlled rotational rheometer (TA Instruments, New Castle, DE) with a strain rate sweep of 0.03 to 300 mPa·s at 10 points / decade, it was surprisingly found that using 10.5% by weight or less of water, based on the weight of the granular wet cement composition to which water is added, particularly for the production of RCC, improved the compressive strength and thus the concrete strength. In the wet cement composition according to the present invention, at 20°C and 514s -1 The viscosity of the interstitial aqueous phase, as measured, achieves optimal strength and compressibility. Furthermore, when the aqueous phase is within this low viscosity range, variations in the useful amount of cellulose ether can be increased to facilitate formulation.

[0054] Admixtures are added in-situ by volume measurement for RCC mixtures and it is crucial that they have a mixing tolerance for excess and under-addition of admixtures for the RCC, rather than by mass. RCC mixtures were too sensitive to high viscosity cellulose ether grades, where a 1 percent fractional change could reduce the strength of the RCC mixture, making them impractical for field use. The inventors found that lower viscosity grade cellulose ethers enable the necessary mixing tolerances required to reliably produce a compressible or paving-ready RCC mixture.

[0055] According to the present invention, the improved lubricity achieved by the water-soluble cellulose ether is not affected by the particle size, sphericity, and roughness of the aggregate material. This is remarkable because, compared to conventional concrete, RCC has a higher volume of aggregate, as well as lower levels of cement and water. Such differences in formulation result in pavements with zero or near-zero slump, while the high aggregate and low water content in the formulation also make RCC highly resistant to compression, resulting in a rougher product compared to conventional concrete pavements. Today, known viscosity modifiers developed for concrete and used in RCC (such as VMAs like polyvinyl alcohol) reduce yield strength (the force required to yield or compress a mixture) and fail to improve lubricity. Rather, using known commercial VMAs to achieve optimized viscosity to avoid consolidation requires unrealistically high levels of VMAs in the RCC wet cement composition.

[0056] Furthermore, the lubricity and strength of products made from roller-compressed cementitious compositions can be further improved by combining cellulose ether with a superplasticizer. The addition of superplasticizers, including polycarboxylate ether-containing plasticizers, lignosulfonate-containing plasticizers, and naphthalene sulfonate-containing plasticizers, can further improve the yield strength and viscosity of RCC concrete and the wet cement compositions used to produce them. Too much superplasticizer can adversely affect the yield strength when combined with cellulose ether, while too little does not change the strength or lubricity of concrete made from wet cement compositions containing them. Therefore, according to the present invention, generally, a combination of less than 1% by weight of superplasticizer based on the total weight of the wet cement composition and 2.5% by weight or less, or preferably 2% by weight or less of cellulose ether, can yield the best results in terms of compression and strength of RCC pavement.

[0057] According to the present invention, the dry mix composition and the wet cementitious compound comprise cellulose ether, granular material, hydraulic binder or cement, and optionally other chemical admixtures. The wet cementitious compound comprises the dry mix composition mixed with water in an amount of 5.0 to 13.0% by weight, or preferably more than 5.0% to 10.5% by weight, based on the total weight of the granular wet cementitious compound, and optionally admixture-auxiliary cementitious material (SCM). As the particle size of the classified aggregate, particularly the coarse aggregate, increases, the water requirement decreases. Therefore, for example, when the coarse aggregate has a sieve particle size of 5 mm or more, or 6 mm or more, the suitable amount of water is in the range of 5 to 6.5% by weight, based on the total weight of the granular wet cementitious compound.

[0058] The one or more cellulose ethers according to the present invention include low-viscosity cellulose ethers. The one or more cellulose ethers may constitute part of a dry mix composition, or they may constitute part of a solution or dispersion in water as the second component of a two-component composition in which the first component constitutes a dry mix composition (without cellulose ethers). At least one of the one or more cellulose ethers has a side chain selected from hydroxyethyl, hydroxypropyl, methyl, and combinations thereof, or preferably hydroxyethyl and methyl. Therefore, the most preferred low-viscosity cellulose ether includes hydroxyethylmethylcellulose.

[0059] In the low molecular weight cellulose ethers of the present invention, alkyl substitutions are described in cellulose ether chemistry by the term "DS". DS is the average number of substituted OH groups per anhydrous glucose unit. Methyl substitutions may be reported, for example, as DS(methyl) or DS(M). Hydroxyalkyl substitutions are described by the term "MS". MS is the average number of moles of etherifying agent bound as ether per mole of anhydrous glucose unit. Etherification with the etherifying agent ethylene oxide is reported, for example, as MS(hydroxyethyl) or MS(HE). Etherification with the etherifying agent propylene oxide is reported correspondingly as MS(hydroxypropyl) or MS(HP). Side groups are determined using the Zeisel method (see: G. Bartelmus and R. Ketterer, Fresenius Zeitschrift fuer Analytische Chemie 286(1977), 161-190).

[0060] According to the present invention, one or more cements refer to any hydraulic cements that solidify and harden in the presence of water. Suitable non-limiting examples of hydraulic cements include Portland cement, hydraulic slaked lime, aluminate cements, such as calcium aluminate cement, calcium sulfoaluminate cement, and calcium sulfate hemihydrate cement; materials having cementitious properties in a pulverized form in the presence of water, which chemically react with calcium hydroxide released by the hydration of Portland cement, such as diatomaceous earth, opalescent chert, clay, shale, fly ash, silica fume, volcanic tuff, and pumice, such as porzolan, which is a siliceous or aluminosilicate material having slaked lime, such as volcanic ash mixed with slaked lime; refractory cements such as crushed blast furnace granulated slag; and magnesia cements such as magnesium phosphate cement, potassium magnesium phosphate cement, and mixtures thereof. Portland cement, as used in the industry, refers to hydraulic cement produced by grinding and calcining a clinker composed of hydraulic calcium silicate, calcium aluminate, and calcium iron aluminate together with one or more forms of calcium sulfate in the inter-grinding additives. Portland cement is classified into types I, II, III, IV, or V according to ASTM C150.

[0061] Examples of granular materials include, but are not limited to, sand, limestone, gravel, granite, and clay, and include classified aggregates of at least one coarse aggregate and at least one fine aggregate. Smaller fine aggregate particles mixed with larger coarse aggregate particles, such as in compositions having two or more particle size distributions, reduce void volume, thereby reducing cement requirements, improving filling, and thus enabling higher strength by adding less water at a given water-to-cement ratio. Preferred fine aggregates are materials with a sieve size of less than 3000 microns, such as limestone, fine silica, talc, fillers, or pigments. Preferred coarse aggregates have a sieve size of 2000 microns or more. Examples include natural or synthetic sands of silica, quartz, crushed round marble, glass spheres, granite, coarse limestone, calcite, feldspar, alluvial sand, or any other durable aggregate, and mixtures thereof.

[0062] Examples of admixtures include, but are not limited to, plasticizers, superplasticizers, retarders, accelerators, defoamers, and viscosity-modifying additives. Admixtures include additives. The compositions of the present invention may also contain, for example, conventional additives in wetting or drying forms such as cement hardening accelerators and retarders, air entrainers or defoamers, shrinkage agents and wetting agents, surfactants, particularly nonionic surfactants, mineral oil dust inhibitors, biocides, plasticizers, organosilanes, poly(dimethylpolysiloxanes) (PDMS) and emulsified PDMS, silicone oils and ethoxylated nonionic substances as defoamers; and coupling agents such as epoxysilanes, vinylsilanes and hydrophobic silanes. [Examples]

[0063] The present invention is illustrated by the following examples. Unless otherwise indicated, all parts and percentages are by weight, all temperatures are in °C, and all preparation and test procedures are carried out under ambient conditions of room temperature of 23 °C and pressure (1 atm). In the following examples and in Tables 1, 2 and 3, the following abbreviations are used: CE: cellulose ether, MPEG: methoxypoly(ethylene glycol), MAA: methacrylic acid, AA: acrylic acid, MMA: methyl methacrylate, PEO: poly(ethylene oxide).

[0064] The following materials were used in the following examples (all components were used as received). Silica sand: 300 micron sieve particle size (Fairmount Minerals 730, Fairmount Minerals LLC, Oklahoma City, OK); Crushed limestone: CaCO3, sieve particle size 44 microns (MICRO-WHITE (trademark) 100, Nagase Specialty Materials NA LLC, Itasca, IL); Artificial sand: 6mm sieve particle size; Portland cement: Type 1 Portland cement; Water (deionized); Cellulose ether 1: Hydroxyethyl methylcellulose (HEMC), WALOCEL (trademark) MW 15000 PFV cellulose ether, The Dow Chemical Co., Midland, MI (Dow), MS=0.17, DS=1.40); Cellulose ether 2:HEMC (WALOCEL (trademark) M-20678 cellulose ether, Dow, MS=0.32, DS=1.73); Cellulose ether 3: Hydroxyethylcellulose, CELLOSIZE® QP 15000H cellulose ether, Dow, MS=2.0, DS=0; Cellulose ether 4:HEMC, WALOCEL (trademark) MT 30000 cellulose ether, Dow, MS=0.40, DS=1.85); Cellulose ether 5: Hydroxypropyl methylcellulose, METHOCEL® 240S cellulose ether, DuPont, Wilmington, DE, MS=0.15, DS=1.81; Cellulose ether 6: HEMC, WALOCEL (trademark) MT 10000 cellulose ether, Dow, MS=0.40, DS=1.85; Cellulose ether 7: HEMC, WALOCEL (trademark) MKW 15000 cellulose ether, MS=0.22, DS=1.64; Cellulose ether 8: HEMC, WALOCEL (trademark) MKX 15000 Cellulose ether MS=0.258, DS=1.60; Viscosity modifier A: Diutan gum, a natural high molecular weight gum produced by aerobic fermentation; KELCOCRETE® DG-F gum, Cp Kelco Co., Atlanta, GA; Viscosity modifier B: Aqueous solution of vinyl alcohol / vinyl acetate copolymer V-MAR(trademark) F100 polymer, WR Grace GCP Applied Technologies, Chicago, IL (Grace); Viscosity modifier C: A blend of sodium gluconate water-reducing agent and polyacrylate carboxylate viscosity modifier, V-MAR(trademark) VSC500, Grace Superplasticizer 1: Polyaromatic (quinoline) sulfonate water-reducing agent VISCTROL™, Euclid Chemical Co., Easton, PA (Euclid); Superplasticizer 2: MELFLUX (trademark) 2651F polycarboxylate ether, BASF, Ludwigshafen, DE; Superplasticizer 3: Sodium lignosulfonate or calcium water-reducing agent, Eucon LR, Euclid; The aqueous poly(AA / MPEG) comb-type polymer esterification product was obtained by combining 4:200g of superplasticizer 2000 MW MPEG (MPEG 2000) with 44.2g of aqueous poly(acrylic acid) containing 50% by weight of sodium hypophosphite, with a pH of 3 and a viscosity of 500 mPa.s measured using a Brookfield viscometer with a #2 spindle at 30 rpm and 25°C. Superplasticizer 5: Sodium naphthalene sulfonate or calcium water-reducing agent (TAMOL® SN, Dow).

[0065] PEO: CarboWax (trademark) polyethylene glycol 400 (380-420 g / mol), Dow. [Table 1] *-Comparative examples are shown.

[0066] To measure the viscosity of the cellulose ether powders in Table A above, the cellulose ether powders were dried overnight in a vacuum oven at 70°C before use. Otherwise, all viscosity modifiers were received in deionized water with a solid content of 1 wt% and used as is. Cellulose ether solutions were prepared for testing with a solid content of 1 wt% by drying the powder, dispersing it in hot water at 70°C, then dissolving it by stirring while cooling to room temperature, and refrigerating overnight (4°C). Viscosity was measured using a strain-controlled rotational rheometer (ARES-G2®, TA Instruments, New Castle, DE) equipped with a Peltier temperature controller, TRIOS® data acquisition software (TA Instruments), and a DIN sample holder with a concentric cylinder, except that for viscosity modifiers B and C, the DIN sample holder was replaced with a double-walled concentric cylinder sample holder. Two tests were performed for each sample, and the average of the two tests was reported.

[0067] In the following examples, the following formulation method was used.

[0068] Preparation of dry mixes and wet cements: The sand, limestone, cement, cellulose ether, and superplasticizer shown in Tables 1A, 1B, 1C, 1D, 1E, and 1F were dry-mixed in a plastic bag for 2 minutes, and then added to water in a mixing bowl (Hobart N50 Mixer, Hobart Corp., Troy, OH). Each mixture was mixed at a low rotation speed (136 RPM) for 15 seconds, scraped from the sides of the mixing bowl, and returned to the bottom of the bowl. The mixture was then mixed again at the same rotation speed. In all tests, the wet cement compositions were tested within 10 minutes of preparation. All compositions totaled 800 g of powder solid, where 800 g is 100% of the total dry powder. The weight percentage of water is based on the weight of the total mixture (granular wet cement) including powder solid and water. [Table 2] [Table 3] [Table 4] [Table 5] [Table 6] [Table 7] 1 In Table 1F, the composition of the present invention contains cellulose ether, while the comparative product does not. [Table 8] [Table 9]

[0069] Test method: The following test method was used in the following examples: Water saturation is defined as the percentage of void volume filled with cement paste. Cement paste includes both volume fractions of cement and water, but excludes classified aggregates. Water saturation is given by the following formula: Water saturation = (V w +V c ) / V V , In the formula, V w V is the volume of water in the wet cement composition, c V is the volume of cement c =m c / ρ c And in the formula, m c ρ is the mass of cement in the wet cement composition, c V is the material density of cement. V The particle density ρ of each material other than cement and water is shown. i This is the total void volume in the entire mixture, determined by measuring the mass of each material other than cement and water. i The density of each material other than cement and water was measured. i The volume of each material was determined by pouring it into a graduated container and measuring its volume. Volume of water V w The mass of water was measured by pouring it into a graduated container. W The density and mass of the cement, ρ were recorded. Similarly, the density and mass of the cement, ρ i and m i We measured the "void volume" V. v =V-Σ(m i / ρ i The void volume was calculated as the porosity or interparticle porosity ε = [V - Σ(m i / ρ i Also called ) / V, it is the reciprocal of the "filling fraction" given by 1-ε. To measure water saturation, the volume V of the given amount of water is used. w Volume V of dry cement c The mass and density of the cement were also measured. The volume of cement was V c =m c / ρ c Record it as such, and in the formula, m cρ is the mass of cement in the sample. c This is the material density of cement. Water saturation = (V w +V c ) / V V To measure the water saturation in the wet cement composition, dry mixtures of cement and water-free sand and aggregate were prepared, and the dry volume V of each mixture was measured by pouring them into graduated containers. The resulting wet cement composition was then formed, and its void volume was determined.

[0070] Ring Shear Test: The shear test was performed according to ASTM D6773-16 (Standard Test Method for Bulk Solids Using Schulze Ring Shear Tester, 2016). Parameters were measured at a given preliminary shear stress of 50,000 Pa using an automated shear ring testing machine controlled by the software RSTCONTROL 95 for MS Windows (Dietmar Schulze, Wolfenbuttel, DE). The indicated wet cement composition samples were filled into ring test cells after being allowed to settle for 10 minutes. The weight of each sample was recorded. The test cells were then placed in the ring shear testing machine and the ring shear test program was started. Three parameters were measured to quantify the properties of the wet cement composition: unconfined yield strength, cohesive force, and internal friction angle. Uniaxial yield strength or yield strength quantifies the strength of a bulk solid under compression or consolidation levels in an unconstrained state (without constrained sidewalls) and is determined as the stress level (perpendicular) at which an unconstrained (unsupported) wet cement composition yields in response to shear. Internal friction angle (lubricity), or the ability of particles in the composition to move relative to each other under shear, is determined as the slope of the yield curve measured by shear tests. Internal friction is equal to the resistance of particles moving relative to each other under compression and shear, and is the ratio of the maximum internal shear force resisting particle movement to the perpendicular force between particles. Lubricity is determined as the slope of the yield curve measured by a ring shear tester, where the curve plots the maximum internal shear at which particles resist movement against the perpendicular stress at which the composition is subjected to perpendicular compression. Lower internal friction indicates higher lubricity. Cohesive force determines the strength of a wet cement composition when no external force is applied and quantifies the attractive force between particles.

[0071] Extrusion of wet cement compositions: A strain-controlled capillary rheometer was set up to characterize the extrusion performance under end-use conditions. The rheometer consisted of a vertically mounted test frame (INSTRON model 5985 Instron, Norwood, MA) equipped with BLUEHILL3 data acquisition software (INSTRON), a 250-kN load cell mounted below the crosshead, a clevis pin (rated 100kN) connecting the load cell to a cylindrical metal piston (44.45mm diameter), a fixed metal cylindrical barrel (200mm length, 44.45mm diameter) fixed to a lower test frame table designed to guide the downward movement of the piston (44.45mm diameter), and a conical transition section from the barrel to a lower mounted metal capillary (12.7mm diameter, 50.8mm length). The setup was placed in a room with constant temperature / humidity (23°C (73°F), 50% humidity). A 300-gram sample of the newly prepared wet cement composition was manually filled into a cylindrical metal barrel. The composition was then pushed down from the barrel into a capillary by a piston, and finally discharged from the capillary as a paste extruded material. A slow piston speed (20 mm / min) was applied until a force F of 0.2 kN was reached, and then the speed was increased to 500 mm / min during the remainder of the extrusion. The load cell force F was measured as a function of piston displacement D. The piston displacement sometimes stopped before the maximum displacement (160 mm) when the load cell approached its upper limit of force (90 kN). The steady-state flow was identified when the extrusion force F measured by the load cell was no longer affected by the piston displacement D. The average force at a displacement of 100 mm (F at D=100 mm) was defined as the steady-state force F. SS This was recorded as follows. Extrusion at 500 mm / min was completed in 9-20 seconds. The extrusion stress or σ was reported as the force F obtained by dividing it by the capillary cross-sectional area A, and was calculated as follows: σ (MPa) = (F[N] / {π·(D die [m] / 2) 2})·(10 -6 MPa / Pa), here D die[m]=0.50 inches / 39.3700787 inches / M = 0.0127M. The extrusion shear strain rate dγ / dt ((dγ / dt) = 32Q / [π·(D die ) 3 = 514 / s) is based on the pace volume velocity Q (Q = v piston ·π·(D die [m] / 2) 2 ), the capillary diameter D die [m], and the piston velocity (v piston ). The shear rate η (Pa·s) at the capillary wall is defined as the ratio of the extrusion stress σ at the capillary wall to the shear extrusion rate dγ / dt (514 s -1 ).

[0072] Rheology of the wet cement composition: Rheology data were measured at 20.0 °C using a stress-controlled rotational rheometer (AR-G2, TA Instruments, New Castle, DE) equipped with a Peltier temperature controller and RHEOLOGY ADVANTAGE (trademark) data collection software (TA Instruments, v5.5.24). The material was sheared via the rotation of a four-blade stainless steel rotor within a stainless steel cup having an inner radius of 15.00 mm. The blades had an outer radius of 14.00 mm. The cup was filled to an immersion height of 42.00 mm. The approximate sample volume was 28.72 mL. The equation used to convert transducer data to rheology is associated with a DIN concentric cylinder apparatus, and thus the rheology data were labeled as apparent rheology. The wet cement composition was tested immediately after being prepared with a Hobart mixer. First, the recovery of the composition from the flow in the Hobart mixer was monitored for 15 minutes using time-resolved small amplitude oscillatory shear flow (angular oscillation frequency of 1 rad / s, stress amplitude in the linear viscoelastic regime). The yield stress (σ Y ) of the recovered unconstrained paste was determined by stress amplitude sweep (1 - 5000 Pa, 25 points / decade). The yield stress is the magnitude of the complex shear modulus |G *The stress amplitude associated with the inflection point of the dependence of | on stress amplitude σ0 was identified. The inflection point was quantitatively determined using a nonlinear fit of data on a semi-logarithmic axis with a sigmoid function. Three iterations were performed, with aliquots of fresh wet cement composition used for each iteration, and the results were averaged.

[0073] Slump of wet cement composition: Slump was determined by mixing the dry components in a plastic bag, adding the powder to the indicated amount of water in a Hobart mixing bowl, mixing twice at speed 1 for 15 seconds, stopping after each mix and scraping the sides of the bowl, allowing the mixture to slosh for 10 minutes, pouring the mixture in three equal layers into a stainless steel cone (height 80 mm, top diameter 40 mm and bottom diameter 90 mm) moistened with water by a spray bottle, placing it on a non-absorbent surface, filling each layer, mixing by moving a steel rod in a circular motion, positioning the rod parallel to the side of the cone, moving it to a vertical position and finishing in the center, finishing the surface of the wet cement composition to be flush with the top of the cone, lifting the cone away from the wet cement composition, measuring the total height of the cone, and recording the slump by reporting the difference between the measured height and the initial height of 80 mm. [Table 10] *A comparative example is shown; 1. Using a stress-controlled rotational rheometer (AR-G2, TA Instruments) at 20.0°C.

[0074] As shown in Table 2 above, only Examples 1-2 to 1-15 of the present invention exhibited an acceptable yield strength of 45 kPa or more at an acceptable low lubrication angle of less than 37 degrees. Therefore, the compositions of the present invention are easily compressible without consolidation and provide sufficient yield strength to resist shape changes in the absence of compressive force. [Table 11] *-Comparative examples are shown.

[0075] As shown in Table 3 above, the wet cement compositions of the present invention in Examples 2-2, 2-3, 2-4 and 2-5, which contain low-viscosity cellulose ether, were all compressed without consolidation until the force no longer displaced. [Table 12] *- Shows comparative examples

[0076] As shown in Table 4 above, with the exception of Example 3-4, which had a large amount of water at a water saturation of 56% and was difficult to compress, all of the wet cement compositions 3-1 to 3-7 of the present invention provided acceptable lubrication angles and yield strengths. [Table 13] *-Comparative examples are shown.

[0077] As shown in Table 5 above, the slump, which is directly correlated with the yield strength of the mixture, is a highly sensitive function of water saturation. At 54% water saturation, all of Examples 5-4, 5-5, and 5-6 have yield strengths exceeding the critical limit for self-consolidation. Despite the low viscosity of cellulose ether 1, at 56% water saturation, the composition of the present invention in Example 5-2 allows for a limited or controlled slump compared to the cellulose ether-free composition in Comparative Example 5-1. On the other hand, superplasticizers increase the slump within reasonable limits. This application also relates to the following aspects. (1) Dry mix composition and granular wet cement composition from water, Based on the total weight of the dry mix composition, 10 to 23% by weight of hydraulic cement is added, A classified aggregate in an amount of 70 to 89.95% by weight based on the weight of the dry mix composition, wherein the classified aggregate comprises i) one or more coarse aggregates having a sieve size of 200 microns to 20 mm, and ii) one or more fine aggregates having a sieve size of 70 microns to less than 3000 microns, and the weight ratio of i) total coarse aggregate to ii) total fine aggregate in the classified aggregate is 4:1 to 0.9:1. Based on the total weight of the dry mix composition, a mixture of cellulose ether or two or more cellulose ethers in an amount of 0.05 to 1.3 wt% is provided, wherein the mixture of cellulose ether or two or more cellulose ethers has an aqueous solution viscosity in the range of 50 to 750 mPa·s at 20°C and a shear rate of 514 s⁻¹, with a cellulose ether solid content of 1 wt% expressed as the average of two tests for each cellulose ether, determined using a strain-controlled rotational rheometer and a strain rate sweep of 0.03 to 300 / s at 10 points / decade, and the aqueous solution is prepared by drying the cellulose ether powder overnight in a vacuum oven at 70°C, dispersing the powder in hot water at 70°C, dissolving it while stirring and cooling to room temperature, and refrigerating it overnight at 4°C to form the aqueous solution. Based on the total weight of the granular wet cement composition, it contains 5.0 to 13% by weight of water, The granular wet cement composition has a water saturation level of less than 58%, defined by the percentage of voids filled with wet cement, which is cement + water, as represented by the following formula: Water saturation = (V w +V c ) / V V、 In the formula, V w V is the volume of water in the wet cement composition, c The volume of cement is V c =mc / ρc, where mc is the mass of cement in the wet cement composition. ρc is the material density of the cement, and V V The total void volume in the total mixture is determined by measuring the particle density ρi of each material other than cement and water, measuring the total mass mi of each material other than cement and water, measuring the total volume V of all materials other than cement and water, pouring all of them into a container and mixing them thoroughly, and then calculating the void volume Vv = V - Σ(mi / ρi). Furthermore, the granular wet cement composition is mixed in a plastic bag with the dry mix composition, the powder is added to the indicated amount of water in a Hobart mixing bowl, mixed twice at speed 1 for 15 seconds each time, stopping after each mix to scrape the sides of the bowl, the mixture is allowed to stand for 10 minutes, the mixture is poured in three equal layers into a water-moistened stainless steel cone via a sponge, placed on a non-absorbent surface, filling each layer, mixing by moving a stainless steel rod in a circular motion, positioning the rod parallel to the sides of the cone, moving it to a vertical position to finish in the center, finishing the surface of the wet cement composition to be flush with the top of the cone, lifting the cone away from the wet cement composition, measuring the total height of the cone, and recording a slump of 30 seconds or less by reporting that the difference between the measured height and 80 mm is 6 mm or less, using a stainless steel cone with a height of 80 mm, a top diameter of 40 mm, and a bottom diameter of 90 mm, and a steel rod stirrer with a diameter of 9.5 mm and a length of 266.7 mm. Having a slump as determined according to C143(2010), Furthermore, a granular wet cement composition in which the total weight percentages of all components in the dry mix composition add up to 100%. (2) The granular wet cement composition according to (1), wherein the composition contains water in an amount of more than 5.0 to 10.5% by weight, based on the total weight of the granular wet cement composition. (3) The cellulose ether or mixture of two or more cellulose ethers has an aqueous solution viscosity of 80-500 mPa·s at 20°C and a shear rate of 514 s⁻¹, with a 1 wt% cellulose ether solids content, expressed as the average of two tests for each cellulose ether, using a strain-controlled rotational rheometer equipped with a Peltier temperature controller, TRIOS® data acquisition software (TA Instruments), and a DIN sample holder with a concentric cylinder, and is determined using a strain-controlled rotational rheometer equipped with a strain rate sweep of 0.03-300 / s at 10 points / decade. The aqueous solution is obtained by drying the cellulose ether powder overnight in a vacuum oven at 70°C and dispersing it in hot water at 70°C. The granular wet cement composition according to (1), which is prepared by dissolving it while stirring and cooling it to room temperature, and then refrigerating it overnight (4°C) to form the aqueous solution. (4) The granular wet cement composition according to (1), wherein the coarse aggregate in the classified aggregate comprises a mixture of a first coarse aggregate having a sieve particle size of 300 to 2000 microns and a second coarse aggregate having a sieve particle size of 2000 microns to 18 mm, and further, the ratio of the sieve particle size of the second coarse aggregate to the sieve particle size of the first coarse aggregate is in the range of 15:1 to 1.5:1. (5) The granular wet cement composition according to (1), further comprising one or more superplasticizers selected from polycarboxylate ether-containing superplasticizers, naphthalene sulfonate-containing superplasticizers, lignosulfonate-containing superplasticizers, or mixtures thereof. (6) A granular wet cement composition according to (1), having a slump of 4.5 mm or less, as determined in accordance with ASTM C143 (2010), using a stainless steel cone with a height of 80 mm, an upper diameter of 40 mm, and a bottom diameter of 90 mm, and a steel rod stirrer with a diameter of 9.5 mm and a length of 266.7 mm. (7) The granular wet cement composition according to (1), wherein the composition has a lubricity of 22° to 36.8° or less, determined as the angle of slope of the yield curve taken as the level of the normal stress at which the composition yields in a shear test plotted against the normal stress being tested, and the normal stress is varied from 25% to 80% of the pre-shear normal stress, measured at a point interval of 5 points / decade of the percentage of the pre-shear normal stress over a normal stress range of 12,500 Pa to at least 40,000 Pa, using 50,000 Pa as the pre-shear normal stress according to ASTM D6773-16 (2016), and then decreasing the normal stress. (8) The granular wet cement composition described in (7) above, having a lubricity of 36.0° or less. (9) The granular wet cement composition according to (1), wherein at least one of the one or more cellulose ethers has a side chain selected from hydroxyethyl, hydroxypropyl, methyl, and combinations thereof. (10) The granular wet cement composition according to (9), wherein at least one of the one or more cellulose ethers is a hydroxyethyl methylcellulose ether having a hydroxyethyl content (MS) in the range of 0 to 0.4 and a methoxyl content (DS) of 1.2 to 1.8, or a hydroxyethyl cellulose having a hydroxyethyl content (MS) of 1.4 to 2.4. (11) It is a method, The granular wet cement composition described in (1) above is formed by mixing water, hydraulic cement, and classified aggregate to form a wet cement composition. The cellulose ether composition and any superplasticizer are added to it as dry powders and mixed in a pump or Pugmill mixer. The granular wet cement composition is applied to the substrate without a mold or formwork, and then A method comprising paving or rolling the wet cement composition to form concrete or a cement layer.

Claims

1. Dry mix composition and granular wet cement composition from water, Based on the total weight of the dry mix composition, 10 to 23% by weight of hydraulic cement is added. A classified aggregate in an amount of 70 to 89.95% by weight based on the weight of the dry mix composition, wherein the classified aggregate comprises i) one or more coarse aggregates having a sieve size of 200 microns to 20 mm, and ii) one or more fine aggregates having a sieve size of 70 microns to less than 3000 microns, and the weight ratio of i) total coarse aggregate to ii) total fine aggregate in the classified aggregate is 4:1 to 0.9:

1. Based on the total weight of the dry mix composition, an amount of 0.05 to 1.3% by weight of cellulose ether or a mixture of two or more cellulose ethers, The cellulose ether or mixture of two or more cellulose ethers is determined using a strain-controlled rotational rheometer, with strain rate sweeps of 0.03 to 300 / s at 10 points / decade, and expressed as the average of two tests for each cellulose ether, with a cellulose ether solids content of 1 wt% at 20°C and 514s. －１ It has an aqueous solution viscosity in the range of 50 to 750 mPa·s at a shear rate of , The aqueous solution is prepared by drying the cellulose ether powder overnight in a vacuum oven at 70°C, dispersing the powder in hot water at 70°C, dissolving it while stirring and cooling to room temperature, and refrigerating it overnight at 4°C to form the aqueous solution, and is a mixture of two or more cellulose ethers. Based on the total weight of the granular wet cement composition, it contains 5.0 to 13% by weight of water, The granular wet cement composition has a water saturation of less than 58%, defined by the percentage of voids filled with wet cement, which is cement + water, represented by the following formula: Water saturation = (V ｗ +V ｃ ) / V Ｖ , where V ｗ is the volume of water in the wet cement composition, and V ｃ is the volume of cement V ｃ = mc / ρc, where mc is the mass of cement in the wet cement composition and ρc is the material density of the cement, and V Ｖ is the particle density ρ of each material other than cement and water ｉ is measured, the total mass m of each material other than cement and water ｉ is measured, the total volume V of all materials other than cement and water is measured, all of them are poured into a container and mixed well, and then the void volume V ｖ = V - Σ(m ｉ / ρ ｉ ) is calculated, which is the total void volume in the total mixture, Furthermore, the granular wet cement composition is mixed with the dry mix composition in a plastic bag, the powder is added to the indicated amount of water in a Hobart mixing bowl, mixed twice at speed 1 for 15 seconds each time, stopping after each mix and scraping the sides of the bowl, the mixture is allowed to stand for 10 minutes, the mixture is poured in three equal layers into a water-moistened stainless steel cone via a sponge, placed on a non-absorbent surface, filling each layer, mixing with a stainless steel rod in a circular motion, positioning the rod parallel to the sides of the cone, moving it to a vertical position and finishing in the center, finishing the surface of the wet cement composition to be flush with the top of the cone, lifting the cone away from the wet cement composition, measuring the total height of the cone, and recording a slump of 30 seconds or less by reporting that the difference between the measured height and 80 mm is 6 mm or less, using a stainless steel cone with a height of 80 mm, a top diameter of 40 mm, and a bottom diameter of 90 mm, and a steel rod stirrer with a diameter of 9.5 mm and a length of 266.7 mm. Having a slump determined according to C143 (2010), Furthermore, a granular wet cement composition in which the total weight percentages of all components in the dry mix composition add up to 100%.

2. The granular wet cement composition according to claim 1, wherein the composition contains water in an amount of more than 5.0 to 10.5% by weight, based on the total weight of the granular wet cement composition.

3. The cellulose ether or mixture of two or more cellulose ethers is determined using a strain-controlled rotational rheometer equipped with a Peltier temperature controller, TRIOS® data acquisition software (TA Instruments), and a DIN sample holder with a concentric cylinder, using strain rate sweeps of 0.03 to 300 / s at 10 points / decade, with a cellulose ether solids content of 1 wt%, expressed as the average of two tests for each cellulose ether, at 20°C and 514s. －１ The granular wet cement composition according to claim 1, having an aqueous solution viscosity of 80 to 500 mPa·s at a shear rate, wherein the aqueous solution is prepared by drying the cellulose ether powder overnight in a vacuum oven at 70°C, dispersing it in hot water at 70°C, dissolving it while stirring and cooling it to room temperature, and refrigerating it overnight (4°C) to form the aqueous solution.

4. The granular wet cement composition according to claim 1, wherein the coarse aggregate in the classified aggregate comprises a mixture of a first coarse aggregate having a sieve particle size of 300 to 2000 microns and a second coarse aggregate having a sieve particle size of 2000 microns to 18 mm, and further, the ratio of the sieve particle size of the second coarse aggregate to the sieve particle size of the first coarse aggregate is in the range of 15:1 to 1.5:

1.

5. The granular wet cement composition according to claim 1, further comprising one or more superplasticizers selected from polycarboxylate ether-containing superplasticizers, naphthalene sulfonate-containing superplasticizers, lignosulfonate-containing superplasticizers, or mixtures thereof.

6. A granular wet cement composition according to claim 1, having a slump of 4.5 mm or less, determined according to ASTM C143 (2010), using a stainless steel cone with a height of 80 mm, an upper diameter of 40 mm, and a bottom diameter of 90 mm, and a steel rod stirrer with a diameter of 9.5 mm and a length of 266.7 mm.

7. The granular wet cement composition according to claim 1, wherein the composition has a lubricity of 22° to 36.8° or less, determined as the angle of slope of the yield curve taken as the level of the normal stress at which the composition yields in a shear test plotted against the normal stress being tested, and the normal stress is 25% to 80% of the pre-shear normal stress, measured at a point interval of 5 points / decade of the percentage of the pre-shear normal stress over a normal stress range of 12,500 Pa to at least 40,000 Pa, using 50,000 Pa as the pre-shear normal stress according to ASTM D6773-16 (2016), and then decreasing the normal stress.

8. The granular wet cement composition according to claim 7, having a lubricity of 36.0° or less.

9. The granular wet cement composition according to claim 1, wherein at least one of the one or more cellulose ethers has a side chain selected from hydroxyethyl, hydroxypropyl, methyl, and combinations thereof.

10. The granular wet cement composition according to claim 9, wherein at least one of the one or more cellulose ethers is a hydroxyethyl methylcellulose ether having a hydroxyethyl content (MS) in the range of 0 to 0.4 and a methoxyl content (DS) of 1.2 to 1.8, or a hydroxyethyl cellulose having a hydroxyethyl content (MS) of 1.4 to 2.

4.

11. It is a method, The granular wet cement composition described in claim 1 is formed by mixing water, hydraulic cement, and classified aggregate to form a wet cement composition. The cellulose ether composition and any superplasticizer are added to it as dry powders and mixed in a pump or Pugmill mixer. The granular wet cement composition is applied to the substrate without a mold or formwork, and then A method comprising paving or rolling the wet cement composition to form concrete or a cement layer.

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