Hydraulic binder with low carbon footprint and high early strength

Abstract

The present invention relates to a new hydraulic binder with a low CO2 footprint, which has a low ground cement clinker content and exhibits higher early strengths than existing LC3 type or other SCM containing binders.

Description

Technical Field

[0001] This invention relates to the field of building construction, and in particular to the field of cement. Background Technology

[0002] In concrete and mortar, cement is used as a hydraulic binder. Portland cement (PC) refers to a hydraulic binder obtained by mixing Portland cement clinker, various admixtures, and a suitable amount of gypsum. PC is the most widely used and common type of cement.

[0003] Portland clinker is produced by calcining and sintering limestone and aluminosilicate materials such as clay together in a cement kiln. Clinker is a crucial component of cement, and its production accounts for a significant portion of the CO2 emissions from cement production. These CO2 emissions come from fuel combustion required to reach the calcination temperature (approximately 1500°C) and the decarbonization of limestone. As of 2018, cement production generated approximately 8% of all carbon emissions worldwide, contributing significantly to global warming. Therefore, reducing the carbon footprint of cement is of paramount importance.

[0004] A conventional approach to reducing the CO2 footprint of cement is to replace part of the ground clinker with a secondary binder material (SCM) that has a lower CO2 footprint, thereby reducing the cement's clinker ratio. Of particular interest in this invention are materials with potential hydraulic properties (requiring external alkali for hydration) or with pozzolanic activity (i.e., requiring some calcium addition for reaction), which serve as binders.

[0005] Among commonly available pozzolanic materials, calcined clay (such as that described in U.S. Patent No. 5,626,665) is a good candidate to partially replace PC clinker. It has relatively high reactivity, and clay is an abundant material. Producing calcined clay requires significantly less energy than Portland clinker because it is calcined at temperatures close to 800°C, lower than the temperatures required for clinker (>1500°C). Furthermore, clay releases only water during calcination, unlike clinker which releases CO2 due to the decomposition of carbonates.

[0006] In the presence of water and calcium (typically from Portland cement), calcined clay reacts via the well-known pozzolanic reaction. The hydrates formed by calcined clay are very similar to those formed by Portland cement, but the reaction kinetics are much slower. This reaction is well described in the scientific literature (Skibsted et al., Cement and Concrete Research 124, 2019). Calcined clay has been used in combination with Portland cement for decades in various countries where high-quality clay is available.

[0007] Recently, researchers discovered that the combination of calcined clay and calcium carbonate (limestone) produces a synergistic effect that enables further hydrate formation, improving the performance of the binder system. Because limestone is an inexpensive and widely available product with a very low CO2 footprint, replacing a portion of Portland clinker with a mixture of calcined clay and limestone (LS, CaCO3) can further reduce the CO2 footprint and binder costs.

[0008] The binder obtained through this method is now called "LC3" binder (limestone calcined clay cement). It is described in John Rossen's master's thesis "Ternary cement blends based on metakaolin and limestone" published in March 2010 at the EPFL, which describes a new type of cement with high mechanical strength and low clinker content, composed of Portland clinker, heat-treated clay, and limestone. Examples of LC3 binder-type compositions are [Portland cement wt% : calcined clay wt% : limestone wt%] = [70:20:10], [55:30:15], [40:40:20].

[0009] This type of adhesive is also described in European patent EP 2 429 966.

[0010] LC3 type adhesives are now widely described in scientific papers.

[0011] Compared to conventional Portland cement, LC3 type cement exhibits a significantly reduced CO2 footprint, typically -30% to -40%, while maintaining similar long-term strength. Systems containing LC3 type binders also demonstrate better durability due to the densification of the structure and changes in its chemical composition. On the downside, while the pozzolanic nature of calcined clay (and all pozzolanic or potentially hydraulic materials) generally results in acceptable long-term strength levels (28 days), its reactivity is not fast enough to compensate for the lower clinker coefficient in the early stages (1 day), leading to lower strength. Therefore, LC3 exhibits significantly lower early strength (1 to 3 days) than PC.

[0012] Therefore, this drawback prevents the use of this adhesive in applications requiring early strength, such as prefabrication, repair, or 3D printing.

[0013] Therefore, it is desirable to provide an alternative, improved binder with a low carbon footprint and enhanced early strength. Summary of the Invention

[0014] Based on the combination of calcium aluminate cement (CAC) or calcium sulfoaluminate cement (CSA) with LC3 type cement (or SCM-containing cement), this invention provides a solution to the limitation of slow strength development of LC3 type binders or other SCM-containing binders, so as to accelerate strength development and provide higher early strength while maintaining a low CO2 footprint.

[0015] The present invention also aims to improve the long-term strength of LC3 or SCM-containing cement, providing higher strength and durability for a comparable CO2 footprint, or providing the same strength for a lower CO2 footprint.

[0016] Compared to LC3 binders or SCM-containing binders, the present invention increases the strength / CO2 footprint ratio at all times, including 1 day and 28 days.

[0017] CAC and CSA are specialty cements with high reactivity, but they are relatively expensive, so they are used in specific applications that require rapid strength development and / or other special properties.

[0018] CAC or CSA can be combined in small amounts with Portland cement to obtain systems with rapid setting and strength development, as described in US9,604,879 or in the article by Amathieu et al. (International Conference on Calcium Aluminate Cement, pp. 303-317, 2001). One disadvantage of this combination compared to a pure PC system is reduced long-term strength. The combination of CAC and PC is well-known and documented, and has been explored in some commercial products, particularly for construction applications.

[0019] On the other hand, combinations of CAC or CSA with pozzolanic and / or potentially hydraulic materials (especially calcined clay and metakaolin) have rarely been explored.

[0020] Some papers, such as (Nowacka et al., Przemyst Chemiczny 96 / 4.770-774), mention the combination of metakaolinite and CAC, but from the perspective of avoiding the transformation reaction of the pure CAC system (the transformation reaction leads to a significant long-term reduction in the strength of pure CAC hydrates).

[0021] These systems consist of CAC and a few percent metakaolin, and contain no Portland cement. There is no intention to reduce the carbon footprint or accelerate strength development in such systems; the goal is simply to avoid long-term strength loss associated with conversion.

[0022] Some literature mentions the addition of CAC to a system known as AAM (Alkali-Activated Materials) (Palomo et al., Proceedings of the Centenary Conference, Avignon, June 30–July 2, 2008, 465–474). AAM consists of pozzolanic and / or potentially hydraulic materials (such as slag or metakaolin), which are activated by the addition of a strong alkali (such as sodium hydroxide). CAC or CSA can be used as a source of activated alumina in these systems to obtain an optimal alumina to silica ratio, as these materials typically have a lower-than-optimal alumina content.

[0023] These systems consist of a large amount of pozzolanic or potentially hydraulic materials, a few percent of strong alkali, and a few percent of CAC or CSA. Portland cement is not used here.

[0024] Information could not be found regarding the simultaneous combination of PC, pozzolanic or potentially hydraulic materials (especially calcined clay), and CAC, and the impact of this combination on early and late strength as well as CO2 footprint.

[0025] Furthermore, the literature describes the effects of CAC or CSA on PC hydration, as well as the effects of volcanic ash on PC hydration, but not the effects of CAC or CSA on volcanic ash hydration. Since CAC or CSA and volcanic ash are sources of aluminate ions, it is expected that the presence of one would affect the reaction of the other. Additionally, since CAC can serve as a source of calcium, it is expected to affect the volcanic ash reaction, but these effects were not found in the literature.

[0026] According to a first objective, the present invention relates to an adhesive composition comprising:

[0027] Portland cement and / or ground Portland cement clinker,

[0028] Calcium aluminate cement (CAC) and / or calcium sulfoaluminate cement (CSA),

[0029] Optional calcium sulfate source,

[0030] Volcanic ash and / or potential hydraulic materials,

[0031] The adhesive composition thereof comprises at least 1.5% calcium sulfate.

[0032] The adhesive of the present invention can

[0033] Maintain a low CO2 footprint for LC3 or SCM-containing binders.

[0034] Improve the early strength of LC3 or SCM-containing adhesives.

[0035] To improve the long-term strength of LC3 or SCM-containing binders to a level similar to or better than that of pure Portland cement.

[0036] Compared to LC3 binders or SCM-containing binders, it increases the strength / CO2 footprint ratio at all times, including 1 day and 28 days.

[0037] The strength of cement can be determined according to European standard EN 196-1 based on the compressive strength at 2 days, 7 days, or 28 days, as shown in the table below:

[0038]

[0039]

[0040] a) For CEM III only

[0041] Three main categories were defined based on the intensity at 28 days: 52.5, 42.5, and 32.5. Early intensity was defined by three subcategories based on the intensity at 2 days: a low early intensity category, denoted by L; a moderate early intensity category, denoted by N; and a high early intensity category, denoted by R.

[0042] For example, the strength provided at 2 days should be greater than 20 MPa for 42.5R and greater than 10 MPa for 42.5N, while the 42.5L category does not require a particular strength level at 2 days.

[0043] However, these categories are not relevant to some applications such as precast, repair mortar, or, for example, 3D printing. In such applications, strength is required two days in advance, sometimes within the first few hours or even less than an hour. In these cases, specific application references can be applied.

[0044] Diluting clinker with SCM to reduce the CO2 footprint results in a secondary effect of reduced early strength. As can be seen from the examples below, this invention enables the use of LC3-type binders or SCM-containing binders with improved early strength. It also reduces the CO2 footprint of the reference cement.

[0045] Although the binder of this invention provides a CO2 footprint very close to that of LC3, it provides the same strength level as Portland cement at 1 day and a surprisingly much higher strength (i.e., long-term strength) at 28 days.

[0046] Therefore, the binder of the present invention can be suitable for all applications with any strength requirements, but has a lower CO2 footprint than standard cement.

[0047] According to an embodiment, the adhesive composition includes:

[0048] Portland cement and / or ground Portland cement clinker,

[0049] Calcium aluminate cement (CAC) and / or calcium sulfoaluminate cement (CSA),

[0050] Calcium sulfate source,

[0051] Volcanic ash,

[0052] The adhesive composition thereof comprises at least 1.5% (by weight) calcium sulfate.

[0053] According to an embodiment, the adhesive composition includes:

[0054] Portland cement (PC) and / or ground Portland cement clinker, by weight, comprise 20% to 90%, preferably 50% to 70%; and / or

[0055] 0.5% to 40%, preferably 2% to 10%, of calcium aluminate cement (CAC) or calcium sulfoaluminate cement (CSA) by weight; and / or

[0056] A calcium sulfate source comprising 1.5% to 44.5% by weight, preferably 2% to 15%; and / or

[0057] Volcanic ash and / or potential hydraulic materials, by weight, comprise 5% to 50%, preferably 10% to 50%.

[0058] More specifically, the adhesive composition may include:

[0059] Portland cement (PC) and / or ground Portland cement clinker, by weight, 50% to 70%.

[0060] 2% to 20% by weight of calcium aluminate cement (CAC) and / or calcium sulfoaluminate cement (CSA),

[0061] Calcium sulfate source of 2% to 15% by weight,

[0062] Volcanic ash and / or potential hydraulic materials by weight, ranging from 10% to 70%.

[0063] According to European standard EN 197-1, Portland cement clinker is a hydraulic material comprising at least two-thirds calcium silicate (3CaO·SiO2 and 2CaO·SiO2) by weight, with the remainder consisting of aluminum- and iron-containing clinker phases and other compounds. The CaO to SiO2 ratio should not be less than 2.0. The magnesium oxide (MgO) content should not exceed 5.0% by weight.

[0064] Portland cement clinker is prepared by sintering a precisely specified mixture of raw materials (raw meal, paste, or slurry) containing elements typically represented as oxides such as CaO, SiO2, Al2O3, Fe2O3, and small amounts of other materials. The raw meal, paste, or slurry is finely dispersed and tightly mixed, thus being homogeneous.

[0065] PC clinker can be prepared by heating a homogeneous mixture of raw materials, including a calcium carbonate source (such as limestone) and an aluminosilicate source (such as clay), at high temperatures in a rotary kiln. Secondary raw materials, such as shale, sand, iron ore, bauxite, fly ash, and slag, may be present.

[0066] The mineral composition of clinker can depend on the raw materials, kiln temperature, and the duration and conditions of heating and cooling.

[0067] According to EN-197-1, minor additives are inorganic natural mineral materials, inorganic mineral materials derived from the clinker production process, or other components. Minor additives can improve the physical properties of cement (such as workability or water retention). Minor additives can be inert or have slight hydraulic properties, potential hydraulic properties, or pozzolanic properties. Depending on their production or delivery state, minor additives can be prepared, i.e., sorted, homogenized, dried, and pulverized. Minor additives should not significantly increase the water requirement of cement, impair the resistance to degradation of concrete or mortar in any way, or reduce the corrosion resistance of reinforcing steel.

[0068] According to the present invention, the cement used herein refers to CEM type cement. As defined by European Standard EN-197-1, CEM cement is a hydraulic binder, i.e., a finely ground inorganic material that, when mixed with water, forms a paste that sets and hardens through a hydration reaction and process, and after hardening, retains its strength and stability even underwater.

[0069] This standard describes different grades of CEM cement. Portland cement corresponds to CEM Type I cement. Portland cement includes:

[0070] 95% to 100% (by weight) of clinker, and

[0071] 0% to 5% (by weight) minor additional ingredients.

[0072] As defined by EN-197-1, other grades of CEM (CEM II to CEM V) contain more and more SCM, such as limestone, blast furnace slag or volcanic ash, to replace clinker.

[0073] EN-197-1 also classifies it according to the long-term strength of CEM. The three grades are 32.5, 42.5 and 52.5, corresponding to the minimum compressive strength at 28 days as measured according to EN-196-1, in MPa.

[0074] Finally, CEM cements were graded based on their short-term strength. N cement exhibited “normal” strength at 2 days, R cement exhibited increased strength at 2 days, and L cement (only applicable to CEM III) had low strength.

[0075] The Portland cement used in this invention can be selected from commercially available grades, such as CEM I 52.5R Milke Premium (PC-M) produced by Heidelberg, CEM I 42.5N Normo (PC-N) produced by Holcim, and CEM I 52.5N (PC-J) from JuraCement. Portland clinker can also be used instead of Portland cement.

[0076] Calcium aluminate cement, or CAC, refers to cement primarily composed of hydraulic calcium aluminate. Alternative names may include "aluminate cement" or "high-alumina cement." The main active phases in crystalline calcium aluminate cement are monocalcium aluminate (CaAl₂O₄, CA) and dodecacalcium heptaaluminate (Ca). 12 Al 14 O 33 (C12A7).

[0077] CAC can have variable amounts of alumina (A) and calcium oxide (C), defined by the C / A ratio. According to embodiments, its molar C / A ratio can be between 1 and 3. CAC can be crystalline and / or amorphous. According to embodiments, calcium aluminate cement comprises (by weight) 2% to 50% crystalline phase and between 50% and 98% amorphous phase.

[0078] CAC typically includes (by weight) 30% to 75% Al2O3, 0.1% to 18% Fe2O3, and 20% to 55% CaO.

[0079] Various CACs are available commercially under different brand names, such as Ciment Fondu, Ternal RG, Ternalwhite, etc.

[0080] Calcium sulfoaluminate cement, or CSA, refers to cement mainly composed of the following mineral phases: calcium sulfoaluminate (Ca4Al6SO15, C4A3$), calcium sulfide (Ca2SiO4, C2S), calcium sulfate (CaSO4, C$), and aluminosilicate (Ca4Al2FeO10, C4AF).

[0081] CSAs can have their own variable contents of alumina (Al2O3), calcium oxide (CaO), and sulfate oxides (SO3).

[0082] CSA typically includes (by weight) 10% to 50% Al2O3, 0.5% to 10% Fe2O3, 3% to 20% SiO2, 4% to 35% SO3 and 35% to 65% CaO.

[0083] Various CSAs are available commercially under different brand names, such as Ali Pre, Ali Cem, and Alpenat.

[0084] Calcium sulfate sources can be hydrated (such as gypsum, CaSO4·2H2O), anhydrous (anhydrite, CaSO4), hemihydrated (hemihydrate, CaSO4·0.5H2O), or mixtures thereof. Gypsum and anhydrite are naturally occurring. Calcium sulfate, including hemihydrate, can also be obtained as a byproduct of certain industrial processes.

[0085] In this invention, the characteristic of the adhesive composition comprising at least 1.5% calcium sulfate refers to the total calcium sulfate content in the adhesive composition. Specifically, the calcium sulfate may be derived from PC, which contains some calcium sulfate in its components, and / or from an optional source of calcium sulfate that may be added.

[0086] Anhydrite, hemihydrate, and gypsum are commercially available or extracted from natural resources.

[0087] Volcanic ash and potential hydraulic materials include fly ash, silica fume, calcined clay, calcined schist, and ground blast furnace slag.

[0088] As used in this paper, the term "potentially hydraulic material" refers to a material that does not possess hydraulic activity on its own but acts as a binder when activated by high pH, ​​such as ground granular blast furnace slag and W-type fly ash. On the other hand, pozzolanic materials require calcium and hydroxide ions for activation and reaction.

[0089] The term "volcanic ash materials," as defined in European standard EN 197-1, refers to natural substances having a composition of silicon or aluminum silicate, or combinations thereof. Volcanic ash materials include:

[0090] Natural volcanic ash (P), i.e., volcanic-origin material or sedimentary rock with appropriate chemical and mineralogical composition; and

[0091] Natural calcined volcanic ash (Q), i.e., volcanic-derived materials, clay, shale, or sedimentary rocks activated through heat treatment.

[0092] According to the implementation method, the volcanic ash material preferably refers to calcined clay.

[0093] Calcined clay is defined as clay that has been heated to a temperature above 500°C, typically between 650°C and 850°C, to remove bound water.

[0094] Clay typically includes montmorillonite, kaolinite, mica and feldspar as aluminosilicate compounds, quartz, and free oxides as impurities.

[0095] When heated, kaolin undergoes dehydroxylation and transforms into metakaolin, which has a complex amorphous structure. The metakaolin content in calcined clay depends on the content of the corresponding clay in the kaolin before calcination. Calcined clay typically comprises between 1% and 99% by weight, preferably between 70% and 95% metakaolin (MK).

[0096] Calcined clay is commercially available, such as Argical M1000.

[0097] According to an embodiment, the binder may further comprise one or more components. Additional components may include a coagulating modifier and / or carbonaceous minerals.

[0098] As used in this article, setting modifiers contain agents suitable for modifying the setting properties of cement, such as accelerators or retarders.

[0099] Specifically, the modifier can be selected from the group consisting of citric acid, tartaric acid, sodium gluconate, Na2CO3, K2CO3, Li2CO3, Li2SO4, and LiOH.

[0100] As used in this article, "carbonaceous minerals" specifically refers to limestone and dolomite.

[0101] Limestone generally refers to carbonate sedimentary rocks; its main materials may include the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3).

[0102] As used herein, according to European Standard EN 197-1, limestone is defined as meeting the following requirements:

[0103] a) The calcium carbonate (CaCO3) content, calculated from the calcium oxide content, should be at least 75% by mass.

[0104] b) The clay content, as determined by the methylene blue test according to EN 933-9, shall not exceed 1.20 g / 100 g. For this test, the limestone shall be ground to approximately 5000 cm² as determined by specific surface area according to EN 196-6. 2 Fineness of / g.

[0105] c) When tested in accordance with prEN 13639:1999, the total organic carbon (TOC) content shall meet one of the following criteria: -LL: not exceeding 0.20% by mass; -L: not exceeding 0.50% by mass.

[0106] According to the embodiments, the binder may further include carbonaceous minerals, typically comprising between 5% and 40% by weight of such carbonaceous minerals.

[0107] In particular, the binder may further comprise limestone, typically between 5% and 40% by weight. Limestone is commercially available, such as Imercarb 3.

[0108] According to the implementation method, the potential hydraulic material is ground granular blast furnace slag.

[0109] According to an embodiment, the adhesive may include:

[0110] Portland cement, by weight, from 0.5% to 80%;

[0111] 0.5% to 20% calcium aluminate cement (CAC) by weight;

[0112] 0.5% to 15% by weight of calcium sulfate source; and

[0113] Potential hydraulic materials, by weight, range from 20% to 95%.

[0114] More specifically, the adhesive may include:

[0115] Portland cement, by weight, from 0.5% to 60%;

[0116] 0.5% to 20% calcium aluminate cement (CAC) by weight;

[0117] 0.5% to 15% by weight of calcium sulfate source; and

[0118] Potential hydraulic materials, by weight, comprise 40% to 95%.

[0119] In these embodiments, ground granular blast furnace slag may be specifically mentioned as a potential hydraulic material.

[0120] According to a second objective, the present invention relates to a method for preparing the adhesive composition of the present invention.

[0121] Typically, the method involves mixing the ingredients at ambient temperature and optionally grinding and / or homogenizing the resulting mixture.

[0122] The present invention also relates to the use of the adhesive in the preparation of construction compositions (i.e., compositions that can be used to manufacture and / or assemble construction components, including building blocks and slabs). Representative construction compositions include mortar and concrete.

[0123] According to another objective, the present invention therefore relates to a construction composition comprising the hydraulic binder of the present invention, the construction composition comprising mortar and concrete.

[0124] The construction composition may include additional ingredients such as sand, gravel, and lime.

[0125] According to another objective, the present invention relates to a method for preparing an application composition, comprising the step of mixing the adhesive of the present invention with water.

[0126] This step is typically performed at ambient temperature. The respective amounts of water and adhesive can vary depending on the type of adhesive, the desired application composition, and its intended use. Generally, the water / adhesive ratio can be between 0.1 and 2.

[0127] According to an alternative embodiment, the present invention also relates to a method for preparing a construction composition, comprising the step of mixing a mortar or concrete comprising at least Portland cement and / or ground Portland cement clinker and volcanic ash and / or potential hydraulic materials with a slurry comprising calcium aluminate cement (CAC) and / or calcium sulfoaluminate cement (CSA) and optionally a calcium sulfate source; wherein the resulting binder composition comprises at least 1.5% calcium sulfate by weight of dry components.

[0128] In this other objective, the slurry comprising calcium aluminate cement (CAC) and / or calcium sulfoaluminate cement (CSA) and optionally a calcium sulfate source may further comprise a retarder.

[0129] For example, inhibitors include boric acid, citric acid, tartaric acid and their salts; phosphorus-containing compounds selected from metaphosphoric acid, phosphorous acid, phosphoric acid, phosphonic acid; and any compound that can be formed by reacting with water to form any of these compounds.

[0130] The slurry may include, by weight, 0.1% to 20%, preferably 0.1% to 15%, more preferably 0.1% to 10%, and more preferably 0.3% to 10% of a retarder relative to the total weight of the calcium aluminate cement and / or calcium sulfoaluminate cement.

[0131] The slurry can be stabilized according to the method described in patent application WO 203 / 093344.

[0132] According to another objective, the present invention also relates to a construction composition that can be obtained by the method defined above.

[0133] According to yet another purpose, the present invention relates to a construction component comprising the construction composition of the present invention.

[0134] According to another purpose, the present invention relates to the use of the adhesive of the present invention in construction, prefabrication, repair mortar or 3D printing. Attached Figure Description

[0135] Figure 1 The compressive strength of compositions 1 to 4 of Example 1 is shown between 1 day and 28 days.

[0136] Figure 2 The CO2 footprints of compositions 1 to 4 of Example 1 are shown.

[0137] Figure 3 The yields of compositions 1 to 4 of Example 1 at 1 day and 28 days are shown.

[0138] Figure 4 The content of calcium hydroxide in compositions 1 to 4 of Example 1 is shown.

[0139] Figure 5 The compressive strength of compositions 1 to 3 and compositions 5 to 6 of Example 2 is shown between 1 day and 28 days.

[0140] Figure 6 The CO2 footprints of compositions 1 to 3 and compositions 5 to 6 of Example 2 are shown.

[0141] Figure 7 The yields of compositions 1 to 3 and compositions 5 to 6 of Example 2 at 1 day and 28 days are shown.

[0142] Figure 8 The cumulative heat of compositions 1 to 3 and compositions 5 to 6 of Example 2 is shown.

[0143] Figure 9 The compressive strength of compositions 1 to 3 and compositions 9 to 10 of Example 3 between 1 day and 28 days is shown.

[0144] Figure 10 The CO2 footprints of compositions 1 to 3 and compositions 9 to 10 of Example 3 are shown.

[0145] Figure 11 The yields of compositions 1 to 3 and compositions 9 to 10 of Example 3 at 1 day and 28 days are shown.

[0146] Figure 12The compressive strength of pure PC compositions containing PC N, LC3-PC compositions, and accelerated LC3 PC compositions is shown between 1 day and 28 days.

[0147] Figure 13 The compressive strength of pure PC compositions containing PC J, LC3-PC compositions, and accelerated LC3 PC compositions is shown between 1 day and 28 days.

[0148] Figure 14 The compressive strength of pure PC compositions containing PC M, LC3-PC compositions, and accelerated LC3 PC compositions is shown between 1 day and 28 days.

[0149] Figure 15 The yields of pure PC compositions containing PC N, LC3-PC compositions, and accelerated LC3 PC compositions at 1 day and 28 days are shown.

[0150] Figure 16 The yields of pure PC compositions containing PC J, LC3-PC compositions, and accelerated LC3 PC compositions at 1 day and 28 days are shown.

[0151] Figure 17 The yields of pure PC compositions containing PC M, LC3-PC compositions, and accelerated LC3 PC compositions at 1 day and 28 days are shown.

[0152] Figure 18 The compressive strengths of the pure PC composition, the LC3 composition, the accelerated LC3 composition, and the composition of Example 5 are shown.

[0153] Figure 19 The yields of the pure PC composition, the LC3 composition, the accelerated LC3 composition, and the composition of Example 5 are shown at 1 day and 28 days.

[0154] Figure 20 The CO2 footprints of the pure PC composition, the LC3 composition, the accelerated LC3 composition, and the composition of Example 5 are shown.

[0155] Figure 21 The ultrasonic velocity of the composition of Example 6 is shown over a period of up to 10 hours.

[0156] Figure 22 The ultrasonic velocity of the composition of Example 6 is shown over a period of up to 24 hours.

[0157] Figure 23 The compressive strength of the composition of Example 6 is shown.

[0158] Figure 24 The CO2 footprint of the composition of Example 6 is shown.

[0159] Figure 25 The yields of the composition of Example 6 at 1 day and 28 days are shown.

[0160] Figure 26 The compressive strength of the composition of Example 7 is shown.

[0161] Figure 27 The CO2 footprint of the composition of Example 7 is shown.

[0162] Figure 28 The yields of the composition of Example 7 at 1 day and 28 days are shown.

[0163] Figure 29 The compressive strength of the composition of Example 8 is shown.

[0164] Figure 30 The CO2 footprint of the composition of Example 8 is shown.

[0165] Figure 31 The yields of the composition of Example 8 at 1 day and 28 days are shown.

[0166] Figure 32 The compressive strength of the composition of Example 9 is shown.

[0167] Figure 33 The CO2 footprint of the composition of Example 9 is shown.

[0168] Figure 34 The yields of the composition of Example 9 at 1 day and 28 days are shown.

[0169] Figure 35 The ultrasonic velocity of the composition of Example 9 is shown over a period of up to 24 hours.

[0170] Figure 36 The compressive strength of the composition of Example 10 is shown.

[0171] Figure 37 The CO2 footprint of the composition of Example 10 is shown.

[0172] Figure 38 The yields of the composition of Example 10 at 1 day and 28 days are shown.

[0173] Figure 36 The compressive strength of the composition of Example 10 is shown.

[0174] Figure 37 The CO2 footprint of the composition of Example 10 is shown.

[0175] Figure 38 The yields of the composition of Example 10 at 1 day and 28 days are shown.

[0176] Figure 39 The compressive strength of the composition of Example 11 is shown.

[0177] Figure 40 The CO2 footprint of the composition of Example 11 is shown.

[0178] Figure 41 The yields of the composition of Example 11 at 1 day and 28 days are shown. Detailed Implementation

[0179] Example

[0180] The raw materials used in the examples and their respective references are listed below.

[0181]

[0182] Table A

[0183]

[0184]

[0185] Table C

[0186]

[0187] Table D

[0188] ACAC 1 ACAC 2 ACAC 3 CAC 1 CAC 2 CaO 43.3 49.0 43.3 37.4 48.4 Al2O3 46.5 41.2 46.5 39.6 37.1 SiO2 4.7 4.0 4.7 4.4 4.6 Fe2O3 1.9 3.0 1.9 16.2 7.2 minerals Amorphous materials Amorphous materials Amorphous materials CA C12A7 Dv50(μm) 5.7 10 12 24 27 CO2 kg / t 1250 1250 1250 700 700

[0189] Table E

[0190] wt% LS1 Dv50(μm) 5.1 CO2 kg / t 5

[0191] Table F

[0192] wt% CA TA NC NG type Citric acid tartaric acid Sodium carbonate Sodium gluconate Dv50(μm) 200 40 49 85 CO2 kg / t 7500 900 1380 1670

[0193] Table G

[0194]

[0195] Table H

[0196] Grinded granular blast furnace slag

[0197] CaO 43.6 Al2O3 10.3 SiO2 36.7 <![CDATA[D v 50(μm)]]> 12 CO2 kg / t 20.5

[0198] Table I

[0199] Micrasil (natural volcanic ash)

[0200] CaO 1.4 Al2O3 12.7 SiO2 77.0 <![CDATA[D v 50(μm)]]> 4.8 CO2 kg / t 100

[0201] Table J

[0202] Example 1

[0203] Table 1 below shows the different binder compositions. The binder was tested in a standard mortar prepared according to EN 196-1, which consisted of 25% binder and 75% sand. Strength values ​​were obtained from the standard mortar according to the test methods described in EN 196-1. All binders in dry powder form were mixed together before mortar preparation.

[0204] The adhesive in composition 1, used as a reference, consists of pure PC.

[0205] The binder in composition 2 is a mixture of PC, calcined clay, limestone, and calcium sulfate, and is therefore an LC3 type binder. It is also used as a reference.

[0206] The binder in composition 3 consists of a mixture of PC, calcined clay, limestone, calcium sulfate, and CAC, representing the accelerated LC3 binder according to the invention. In this case, a portion of the limestone present in LC3 is replaced by a mixture of CAC and calcium sulfate comprising 10% of the total binder content.

[0207] The binder in composition 4 consists of a mixture of PC, quartz, limestone, calcium sulfate, and CAC. It is identical to composition 3 except that the calcined clay is replaced by quartz sand (an inert material). When comparing composition 3 and composition 4, composition 4 is used to demonstrate the effect of the calcined clay.

[0208] The adhesive composition is expressed as a weight percentage of the total weight of the adhesive, and the mortar composition is expressed in grams.

[0209] The compressive strength of each adhesive was measured from day 1 to day 28 according to EN 196-1. The strength of each composition at day 1 and day 28 was compared with PC and LC3 references.

[0210] The CO2 footprint was calculated based on the footprint of each component of the binder. The footprint of each composition was compared with PC and LC3 references.

[0211] For 1 day and 28 days, the binder yield was calculated taking into account the strength of each unit of CO2-related mortar.

[0212] Similarly, the yield of each composition was compared with PC and LC3 references.

[0213]

[0214]

[0215] The results are as follows Figure 1 As shown.

[0216] like Figure 1 As shown, the LC3 binder (composition 2) exhibited lower early strength at 1 day than pure PC (composition 1), while the binder (composition 3) of the present invention exhibited 67% higher early strength than the LC3 binder, while having a comparable CO2 footprint. Figure 2 As shown. In fact, the CO2 footprint of accelerated LC3 (composition 3) is only 14% higher than that of conventional LC3 (composition 2), and is still 32% lower than that of pure PC.

[0217] Composition 4, which uses inert filler instead of calcined clay, exhibits good early strength, indicating that the clay does not have a synergistic effect on strength on the first day. Its slightly better strength may be related to the known effects of the filler.

[0218] Starting from day 7, there was a significant difference between composition 3 and composition 4, indicating that the clay began to hydrate and this contributed to the strength.

[0219] At 28 days, the strength of LC3 was comparable to that of pure PC, consistent with the literature. When it came to accelerated LC3, its strength was significantly higher, 51% higher than the LC3 system. The substantial increase in later-stage strength was unforeseen due to the addition of CAC and calcium sulfate, as these two binders are expected to primarily enhance early-stage strength.

[0220] No signs of negative interaction between calcined clay and CAC were detected. In fact, there appears to be a positive synergistic effect between these binders, as the accelerated system according to the invention significantly improves the long-term strength of LC3, as much as its short-term strength. The long-term strength is even improved compared to the pure PC system: accelerated LC3 (composition 3) provides 67 MPa at 28 days, an increase of 40%, compared to 48 MPa for pure PC (composition 1), which is quite surprising considering that the hydraulic binder content of composition 3 is only 83.3% compared to 100% for composition 1.

[0221] To better compare different formulations, the ratio of compressive strength per ton of CO2 can be considered, which is referred to here as the yield of the binder system. Figure 3 The yields of the four compositions are shown in the figure.

[0222] At day 1, the yield of the LC3 system was slightly lower than that of pure PC, meaning that more CO2 was emitted to achieve the same intensity level. At day 28, the trend reversed, and the yield of LC3 was 56% higher than that of PC.

[0223] On the other hand, LC3 accelerates the yield of PC and LC3 better in both the short and long term. At 1 day, its yield is 32% higher than PC, and at 28 days, it is 106% higher. This means that, for the same amount of CO2, the bonding system according to the invention provides twice the strength of Portland cement.

[0224] To better understand the hydration mechanisms occurring in these systems, compositions 1 through 4 were tested as binder pastes consisting solely of binder and water as described in Table 1, with a water / binder ratio of 0.4. These pastes were then analyzed by XRD to quantify their hydroxyapatite content at 1, 3, 7, and 28 days. Evolution of hydroxyapatite content in the systems ( Figure 4 () is an indirect indicator of the evolution of volcanic ash reaction.

[0225] In the pure PC system (composition 1), calcium hydroxide is released by the hydration of PC, and its amount increases over time.

[0226] Compared to the pure PC system, the LC3 system, with only half the amount of Portland, is expected to form approximately half the amount of calcium hydroxylite, as observed at day 1 when the metakaolinite may not have reacted yet. At day 3, the amount of calcium hydroxylite is less than half that of PC, indicating that the volcanic ash reaction of the metakaolinite has begun and consumed some of the calcium hydroxylite. From that point onward, the amount of calcium hydroxylite decreases even more rapidly, indicating an accelerated volcanic ash reaction.

[0227] At 28 days, the LC3 paste still contained some calcium hydroxide, but much less than the PC paste, because the calcium hydroxide was consumed in the volcanic ash reaction of the metakaolinite.

[0228] In the accelerated LC3 system (composition 3), calcium hydroxylite produced by PC hydration is consumed by the formation of ettringite. The amount of calcium hydroxylite remains low over time, indicating that it is continuously consumed by the pozzolanic reaction as it forms through PC hydration. Similar to LC3, some calcium hydroxylite remains in the accelerated LC3 system over time, ensuring protection of the reinforced concrete.

[0229] For composition 4 in which the calcined clay is replaced by inert quartz, the amount of calcium hydroxide in the system increases after 1 day because it is not consumed by any volcanic ash reaction.

[0230] These results confirm that calcined clay undergoes a volcanic ash reaction, consuming calcium hydroxide and contributing to the strength development of the system.

[0231]

[0232]

[0233] The binders in compositions 3, 5, and 6 are all composed of a mixture of PC, calcined clay, limestone, calcium sulfate, and CAC, and these compositions contain different proportions of CAC+C$ to illustrate possible variations of the accelerated LC3 binder according to the invention.

[0234] Composition 3 contains 10% of an accelerator binder (CAC+C$), composition 5 contains 5% of the same accelerator binder, and composition 6 contains 7% of an accelerator binder. The accelerator binder replaces an equal amount of limestone in the compositions, keeping the total amount of binder in all compositions constant.

[0235] Figure 5 The effect of the amounts of CAC and calcium sulfate in the binder is shown. It compares three compositions containing different amounts of accelerator binder and contrasts them with reference composition 1 (pure PC) and composition 2 (LC3).

[0236] When increased amounts of the combination of CAC and calcium sulfate were added to replace portions of limestone (5%, 7%, and 10% of the total binder), short-term strength increased (by 73%, 87%, and 67%, respectively, compared to reference LC3). This was expected given the high reactivity of CAC. Of concern, the amount of accelerator appeared to have little effect on the strength achieved at one day, as compositions 3, 5, and 6 exhibited similar strengths.

[0237] Even more surprisingly, the addition of an accelerator significantly improved long-term strength, resulting in performance even better than pure PC. This strong positive impact on long-term strength again demonstrates the synergistic effect of the accelerator and the pozzolanic reaction of metakaolin. Here, higher amounts of accelerator resulted in a more significant increase in long-term strength, up to 51%.

[0238] like Figure 6 As shown, adding an accelerator has only a small effect on the CO2 footprint of the binder. All accelerated LC3 systems have significantly lower CO2 footprints than pure PC (up to 36% lower), while providing better strength.

[0239] By analyzing the strength yield per ton of CO2 of the binder ( Figure 7 It can be observed that regardless of the amount of accelerator binder, the yield of accelerator binder is superior to that of pure PC and LC3 in both the short and long term.

[0240] Figure 8 Analysis of the cumulative heat obtained by microcalorimetry, as shown in the figure, indicates that adding an increased amount of CAC+ calcium sulfate accelerates the hydration reaction and releases heat earlier.

[0241] This faster response can be associated with the faster intensity development observed in accelerated LC3 systems (compounds 3, 5, and 6).

[0242] The accelerated system exhibits a two-step reaction, which translates into two exothermic steps, more pronounced in the system containing 10% accelerated binder. The accumulated heat of the accelerated system at 150 h is superior to that of the LC3 system, indicating further reactions occurring in these systems. The level of heat released by the accelerated system at 150 h is proportional to the amount of CAC added.

[0243] Surprisingly, the accelerated LC3 system released less heat than or similar to that of the pure PC system over 150 hours (6.25 days), even though the intensity of the accelerated LC3 system may be higher than that of the pure PC system during this period (since they are both higher at 7 days). This suggests that different thermal intensities are occurring at different rates.

[0244]

[0245]

[0246] The compositions in this example demonstrate the effect of reducing the amount of PC in the adhesive composition. This example compares composition 1 (100% PC), composition 2 (LC3, containing 50% PC), and composition 3 (accelerated LC3, also containing 50% PC) with the following compositions:

[0247] Composition 9 = Accelerated LC3 containing 45% CEM I. The lower PC content is compensated by increasing limestone, keeping the total binder amount constant. The rest of the composition is the same as composition 3.

[0248] Composition 10 = Accelerated LC3 containing 40% CEM I. The lower PC content is compensated by increasing limestone, keeping the total binder amount constant. The rest of the composition is the same as composition 3.

[0249] from Figure 9 It can be observed that reducing the amount of PC in the accelerated LC3 binder leads to a gradual decrease in both early and later strength. At day 1, the strength of the accelerated system is lower than that of the pure PC system, but still better than that of the LC3 system.

[0250] Starting from day 7, the accelerated LC3 system exhibited higher strength than pure PC and LC3, indicating that, according to the present invention, the addition of an accelerating binder can fully compensate for the reduction of PC in the binder. The accelerated LC3 system containing only 40% PC in its composition had 15% higher strength than the 100% PC system and 24% higher strength than the LC3 system containing 50% PC.

[0251] The reduction in PC content in the adhesive naturally leads to a reduction in its CO2 footprint, such as... Figure 10 As shown.

[0252] Since accelerating the reduction of PC content in the LC3 system leads to both a decrease in strength and a reduction in its CO2 footprint, the yields obtained for compositions 3, 9, and 10 are very similar. Figure 11 They are still up to 37% higher in yield than the LC3 system and up to 113% higher in yield than pure PC, which means that more than twice the MPa is obtained for every ton of CO2 emitted by the binder.

[0253] Example 4:

[0254] Different types of PCs were tested to illustrate possible variations of the invention.

[0255] Compositions 7-1, 7-2, and 7-3 are based on CEM I 52.5N Jura cement, while compositions 8-1, 8-2, and 8-3 are based on CEM I 52.5R Milke Premium. These compositions are similar to the aforementioned compositions 1 (pure PC), 2 (LC3 type binder), and 3 (accelerated LC3 type binder) based on CEM I 42.5N Holcim Normo, differing only in the type of PC used.

[0256] A comparison of the three types of PC architectures will be able to verify whether the trends described in Example 1 are effective for different types of PCs.

[0257] Table 4:

[0258]

[0259]

[0260] Table 5:

[0261]

[0262]

[0263] The compressive strength obtained using Holcim Normo PC (PC N) is shown together with the compressive strength obtained using Jura PC (PC J) and Milke Premium PC (PC M). Figures 12-14 ).

[0264] The properties of compositions containing PC J are very similar to those containing PC N. At all times, the accelerated LC3 system outperforms the pure PC system: compressive strength is 18% higher at day 1 and 50% higher at day 28. Starting from day 7, the accelerated LC3 system also outperforms pure PC, showing a 29% improvement at day 28.

[0265] The trend was similar when using PC M. At all times, the strength of accelerated LC3 was significantly higher than that of the LC3 system (+60% at 1 day and +28% at 28 days). However, because this cement exhibited very high performance at all times, the accelerated LC3 system did not surpass PC M except at 7 days. At 1 day and 28 days, the strength of accelerated LC3 was 6% and 3% lower than that of pure PC, respectively.

[0266] However, when considering the yield of the composition, the difference between accelerated LC3 and PC becomes more significant, demonstrating the clear advantage of using the accelerated LC3 proposed in this invention.

[0267] In all cases, for all tested PCs, accelerated LC3 yielded higher yields than both LC3 and pure PC systems. At 1 day, yields were increased by up to 39% compared to the corresponding PC and by up to 47% compared to the corresponding LC3.

[0268] At 28 days, the accelerated LC3 yield was 43% to 106% higher than the corresponding PC yield, and 13% to 33% higher than the corresponding LC3 yield. Figures 15-17 ).

[0269] It confirms that accelerated LC3 outperforms regular LC3 even when using different types of PCs, and this holds true in both the short and long term.

[0270] The LC3 acceleration surpasses the strength of pure PC systems, except for those with very high strength, such as Milke Premium with a strength of 74MPa over 28 days.

[0271] If CO2 footprint is taken into account, then Accelerated LC3 is significantly superior to PC, and even to MilkePremium, achieving a higher intensity yield per tonne of CO2 emissions for binders.

[0272] Example 5

[0273] Examples of binders consisting of a mixture of PC, calcined clay, limestone, calcium sulfate, and calcium aluminate are shown in Tables 6 and 7 below, with different types of calcium aluminate accelerators. In composition 3, amorphous CAC (ACAC) with a calcium to alumina (C / A) ratio of 1.7 and a fine particle size (d50 = 5.7 μm) is used to accelerate the system. In composition 11, ACAC with a higher C / A ratio is used, and in composition 12, coarser ACAC (d50 = 12 μm) is used.

[0274]

[0275]

[0276]

[0277]

[0278]

[0279]

[0280]

[0281]

[0282]

[0283]

[0284]

[0285]

[0286] We observed that the LC3 system (and the pure PC system) showed no strength at 6 hours, regardless of the clay used. However, the accelerated system exhibited a compressive strength close to 10 MPa. At 1 day, the strength levels of LC3 containing both clays were similar, 56% lower than the strength level of the pure PC reference. On the other hand, the strength of the accelerated system was 36% to 40% higher than that of PC.

[0287] At 28 days, the compressive strength of LC3 with more kaolin clay was 55 MPa, slightly higher than that of pure PC (50 MPa), while the compressive strength of LC3 with less kaolin clay was only 44 MPa.

[0288] When mineral accelerators are added to the LC3 system, the final strength is significantly improved. The improvement is 33% compared to non-accelerated LC3 in the case of CC1, and 59% in the case of CC2. Both accelerated systems are much stronger than PC, resulting in a 113% increase in yield for CC1 and a 108% increase for CC2.

[0289] In summary, regardless of the type of clay, the addition of mineral accelerators improved the performance of LC3 at all times. Furthermore, the mineral accelerators compensated for the lower performance of LC3 containing less kaolin clay, bringing it to a level similar to that achieved with more kaolin clay.

[0290]

[0291]

[0292]

[0293]

[0294] Other types of retarders can also be used in combination with mineral accelerators. In this embodiment, a system containing sodium gluconate and citric acid is provided. Sodium gluconate is a strong retarder used to ensure a longer setting time, while citric acid is a weak retarder used in systems requiring a shorter setting time.

[0295] Using 0.18% sodium gluconate, the accelerated LC3 starting point was around 4 hours, comparable to the system using 0.43% tartaric acid. However, the strength decreased slightly at 6 hours, while at 24 hours, the compressive strength using both retarders reached the same level. At 28 days, the strength was even better than that using tartaric acid, reaching 86 MPa, an increase of 43% compared to the pure PC system and 54% compared to the non-accelerated LC3.

[0296] Compared to pure PC, non-accelerated LC3, and accelerated LC3 containing tartaric acid, the use of citric acid improved performance at all stages. In fact, in this very fast-acting system, the highest strength was achieved at 6 hours, reaching 12.5 MPa, and the strength reached 90 MPa at 28 days, representing a 61% improvement compared to non-accelerated LC3.

[0297] Given their low dosage, the type of retarder has little effect on the CO2 footprint of the binder. The choice of retarder should be based solely on the expected performance, especially the desired setting time. Weaker retarders, such as citric acid, can be used in systems requiring short setting times, and these weaker retarders result in higher 6-hour strength. Stronger retarders, such as sodium gluconate, allow for setting times of several hours, but yield slightly lower 6-hour strength. From 24 hours onwards, the strength obtained using different retarders is similar, and their yields are also similar, ranging from 32% to 52% higher than those of the LC3 system.

[0298] Example 10: Acceleration of cement containing natural volcanic ash

[0299] In this embodiment, a mixed cement is prepared by mixing 65% CEM I and 35% Micrasil (natural volcanic ash). This mixed cement is then accelerated using a mineral accelerator.

[0300] Results for 28 days are not yet available; therefore, a comparison between accelerated and non-accelerated systems was made based on 1-day and 7-day intensities. Results are as follows... Figures 36-38 As shown.

[0301] Table 13

[0302]

[0303]

[0304] The addition of the accelerator increased the 1-day strength by 53%, from 14.4 MPa to 22.0 MPa, and the 7-day strength by 19%, indicating that the mineral accelerator can also improve the strength development of low CO2 cement containing natural volcanic ash.

[0305] The addition of the mineral accelerator resulted in only a 4% increase in the binder's CO2 footprint, leading to better yields across all time periods. At day 1, the accelerated system yielded a 47% increase over the non-accelerated system, and a 14% increase at day 7.

[0306] Example 11: Acceleration of LC3 based on CEM II 32.5NB / LL

[0307] In this embodiment, CEM II 32.5NB / LL is combined with calcined clay to prepare an LC3-like system, but using only two components instead of three. In fact, since CEM II B / LL already contains limestone, it only requires the addition of clay, which can be convenient, for example, in dry-mixing equipment when the number of available silos is limited. The results are as follows... Figures 39-41 As shown.

[0308]

[0309] Replacing 20% ​​of CEM II with calcined clay yields a two-component LC3, which has a slightly lower 24-hour strength than pure CEM II, but a 29% higher 28-day strength.

[0310] When this LC3-like system was accelerated using mineral accelerators, significant improvements were observed in both the short and long term. At 1 day, the intensity increased by 106% compared to CEM II and by 151% compared to the LC3-like system. At 28 days, the intensity increased by 97% compared to CEM II and by 53% compared to the LC3-like system.

[0311] Since the CO2 footprint of the accelerated system is very close to that of the LC3-like system and lower than that of CEM II, the significant increase in intensity results in much higher yields at both 1 day and 28 days.

[0312] The following ultrasonic measurements were performed:

[0313] The structuring or hardening of mortar was tracked using an ultrasonic device. Fresh mortar was placed in a cylindrical silicone mold with a circular base 5 cm in diameter and 5 cm in height. An ultrasonic transmitter was placed in direct contact with the mortar in an opening on one side of the mold; an ultrasonic sensor was placed in another opening on the opposite side of the circular section. The transmitter and sensor were separated by a 3 cm layer of mortar, which, over time, became structured and hardened. The propagation speed of the ultrasonic waves depended on the hardness of the mortar; the harder the mortar, the faster the ultrasonic waves. The speed of the ultrasonic waves was recorded every second over 24 hours, allowing for the plotting of a curve showing the evolution of the speed over time, which could be directly correlated with the hardening of the mortar.

[0314] For the two GGBS-based adhesives tested, faster structuring was observed when an accelerator was added, such as... Figures 21-22 The ultrasonic measurement is shown.

[0315] This faster structuring translates into compressive strength at 6 hours, which is not present in either the non-accelerated system or pure PC. The 24-hour strength was increased by 27% for the PC+GGBS+limestone system and by 34% for the PC+GGBS system by using an accelerator.

[0316] Adding accelerators also significantly increased the 28-day strength, producing even better strength than pure PC.

[0317] Although the CO2 footprint of the GGBS-containing binder increased slightly due to the addition of the accelerator, the yield was improved. The yields of all GGBS-based systems were significantly higher than those of pure PC, with the accelerated systems exhibiting the highest yields. In fact, the 28-day yield of the accelerated PC+GGBS+limestone system was 8% higher than that of the non-accelerated system and 178% higher than that of pure PC. For the accelerated PC+GGBS system, the yield was 25% higher than that of the non-accelerated system and 240% higher than that of pure PC.

Claims

1. An adhesive composition comprising: Portland cement and / or ground Portland cement clinker, Calcium aluminate cement or a mixture of calcium aluminate cement and calcium sulfoaluminate cement. Optional calcium sulfate source, Volcanic ash materials and / or potential hydraulic materials, The adhesive composition comprises, by weight, at least 1.5% calcium sulfate. The calcium aluminate cement comprises 50% to 98% amorphous phase by weight.

2. The adhesive composition according to claim 1, comprising: Portland cement and / or ground Portland cement clinker, by weight, comprising 20% ​​to 90%. 0.5% to 40% by weight of calcium aluminate cement or a mixture of calcium aluminate cement and calcium sulfoaluminate cement. Calcium sulfate source of 1.5% to 44.5% by weight, 5% to 50% by weight of pozzolanic materials and / or potential hydraulic materials.

3. The adhesive composition according to claim 1, comprising: Portland cement and / or ground Portland cement clinker, by weight, comprising 20% ​​to 70%. 2% to 20% by weight of calcium aluminate cement or a mixture of calcium aluminate cement and calcium sulfoaluminate cement Calcium sulfate source of 2% to 15% by weight, 10% to 70% by weight of pozzolanic materials and / or potential hydraulic materials.

4. The adhesive composition according to claim 1, wherein, Volcanic ash materials are calcined clay.

5. The adhesive composition according to claim 1, comprising: Portland cement, by weight, from 0.5% to 80%; 0.5% to 20% calcium aluminate cement by weight; 0.5% to 15% by weight of calcium sulfate source; and Potential hydraulic materials, by weight, range from 20% to 95%.

6. The adhesive composition according to claim 1, comprising: Portland cement, by weight, from 0.5% to 60%; 0.5% to 20% calcium aluminate cement by weight; 0.5% to 15% by weight of calcium sulfate source; and Potential hydraulic materials: 40% to 95% by weight.

7. The adhesive composition according to claim 1, wherein, The potential hydraulic material is ground granular blast furnace slag.

8. The adhesive composition according to claim 1, further comprising 5% to 40% by weight of carbonaceous minerals.

9. The adhesive composition according to claim 1, further comprising one or more coagulation modifiers.

10. The adhesive composition according to claim 9, wherein, The modifier is selected from the group consisting of citric acid, tartaric acid, sodium gluconate, Na2CO3, and K2CO3.

11. The adhesive composition according to claim 1, wherein, The calcium aluminate cement comprises, by weight, 30% to 75% Al2O3 and 0.1% to 18% Fe2O3.

12. The adhesive composition according to claim 1, wherein, The volcanic ash material comprises between 1% and 99% metakaolin by weight.

13. A method for preparing a construction composition, comprising mixing the adhesive composition according to claim 1 with water.

14. A construction composition obtainable by the method of claim 13.

15. The construction composition according to claim 14, wherein the construction composition is a mortar composition or a concrete composition.

16. Use of the binder composition according to claim 1 in 3D printing.

17. A construction component comprising the construction composition of claim 14.

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