Cementitious composition comprising laterite

Abstract

The invention relates to a cementitious composition with a high level of replacement of cement by laterite and comprising an activator of a salt of an alkali or alkaline earth metal selected from hydroxides, formates, chlorides, sulfates and / or nitrates. The invention also relates to the use of such a cementitious composition as a brick adhesive.

Description

Technical Field

[0001] This invention relates to cementitious compositions in which laterite is used to replace cement at a high level. The invention also relates to the use of such cementitious compositions as brick adhesives. Background Technology

[0002] Cement-based building materials, especially concrete or mortar, rely on cementitious binders. Cementitious binders are typically hydraulic binders, the most abundant of which is cement, particularly Portland cement. However, the use of cement, and especially Portland cement, has a high environmental footprint. A major reason is the high CO2 emissions associated with cement manufacturing. Therefore, many efforts have been made to at least partially replace cement as a binder in building materials.

[0003] One possibility is to use materials with cementitious properties, volcanic ash, and / or potentially hydraulic materials as cement substitutes. One known material of this type is laterite. Laterite is a surface product frequently found in tropical regions and is formed through intense and prolonged weathering of the underlying rocks.

[0004] For example, AT John et al. reported on the use of laterite as a partial cement substitute in concrete in the International Journal of Scientific & Engineering Research (2019, Vol. 10, No. 12, pp. 100-104).

[0005] It is known that replacing cement with materials possessing cementitious properties, pozzolanic materials, and / or potentially hydraulic materials can affect the properties of the resulting fresh and hardened mortar or concrete. This is especially true at high substitution levels. High substitution levels are required to minimize the environmental footprint of concrete or mortar.

[0006] In particular, when cement is replaced with cementitious materials, pozzolanic materials and / or potential hydraulic materials, a suitable activator is required to achieve the desired strength of the resulting cementitious material.

[0007] Therefore, there is a persistent need to provide cementitious compositions that replace cement with a high level of laterite while still establishing sufficient mechanical strength for a given application. Summary of the Invention

[0008] The object of this invention is to provide a cementitious composition that replaces cement with a high level of laterite while still achieving sufficient strength (especially bond strength). In particular, the object of this invention is to provide a cementitious composition that replaces cement with a high level of laterite and can be used as an adhesive for cementitious bricks.

[0009] Surprisingly, the cementitious composition of claim 1 has been found to achieve these objectives. Furthermore, it has been surprisingly found that the cementitious composition of claim 1 can be used as a cementitious brick adhesive.

[0010] In particular, activators selected from alkali metal or alkaline earth metal salts, including hydroxides, formates, chlorides, sulfates, and / or nitrates, have been shown to improve the bond strength of cementitious materials containing hydraulic binders and high-level laterite-based cement substitutes. The bond strength can be further improved by adding hydrophobic agents.

[0011] Further aspects of the invention are the subject of the additional independent claims. Preferred embodiments of the invention are the subject of the dependent claims. Detailed Implementation

[0012] In a first aspect, the present invention relates to cementitious compositions comprising or consisting of the following:

[0013] a) A hydraulic binder, comprising (in each case, by total dry weight relative to the hydraulic binder)

[0014] ai) 10-90% by weight, preferably 50-60% by weight of at least one type of cement.

[0015] aii) 10-90% by weight, preferably 40-50% by weight of laterite.

[0016] (b) At least one activator selected from alkali metal or alkaline earth metal salts of hydroxides, formates, chlorides, sulfates and / or nitrates.

[0017] Examples of cementitious compositions include concrete and mortar.

[0018] The cement mentioned in this article is Portland cement, aluminate cement, sulfoaluminate cement, or a mixture thereof.

[0019] Portland cement is preferably CEM I, CEM II, CEM III, CEM IV and / or CEM V according to standard EN 197-1:2011. However, Portland cement according to other international standards, such as ASTM standards or Chinese standards, may also be used. The term "aluminate cement" specifically refers to cement with an aluminum content (measured as Al2O3) of at least 30% by weight, especially at least 35% by weight, and particularly 35-58% by weight. Preferably, aluminate cement is alumina cement according to standard EN 14647:2006. Preferably, sulfoaluminate cement is calcium sulfoaluminate cement (CSA).

[0020] In particular, at least one type of cement is selected from Portland cement of type CEM I, CEM II, CEM III, CEM IV, CEM V or a mixture thereof according to standard EN 197-1:2011.

[0021] The hydraulic binder of the present invention may additionally contain at least one of slag, fly ash, microsilica, lime and / or gypsum.

[0022] Laterite is a surface product frequently found in tropical regions, formed through intense and prolonged weathering of underlying rocks. Laterite is primarily composed of oxides of silicon, aluminum, and iron. For example, the chemical composition of laterite can be 55 wt% SiO2, 20 wt% Al2O3, 15 wt% Fe2O3, 5 wt% MgO and CaO, 2 wt% Na2O and K2O, and 3 wt% other oxides (including TiO2 and P2O5). The chemical composition of laterite can be determined by XRF analysis.

[0023] Laterite is typically composed of a mixture of clay-based aluminosilicates and iron oxides. Typical minerals found in laterite include kaolinite, halloysite, goethite, hematite, and gibbsite. However, other minerals may also be present. The phase composition of laterite can be determined through XRD analysis.

[0024] Laterite can be used in uncalcined or calcined form. Calcinated laterite is especially low-temperature calcined laterite that has been heat-treated in a rapid calcination process at 500-1200°C or 800-1100°C. Suitable rapid calcination processes are described, for example, in WO 2014 / 085538.

[0025] According to the embodiments, in the cementitious composition of the present invention, the laterite is in an uncalcined form and contains 40-90% by weight, preferably 50-70% by weight, of aluminosilicate and 10-60% by weight, preferably 30-50% by weight, of iron oxide or thereof.

[0026] According to the embodiments, in the cementitious composition of the present invention, the laterite is in a calcined form and contains at least 40% by weight of calcined clay, especially metakaolinite, and at least 30% by weight of iron oxides, especially wuestite, hematite and / or magnetite.

[0027] Preferably, the laterite is sieved. According to the embodiment, the laterite has a particle size of less than 150 μm as measured by sieve analysis as described, for example, in standard ASTM C136 / C136M.

[0028] Particularly preferred is a cement-to-lattice weight ratio in the hydraulic binder of 10:1 to 1:10, preferably 2:1 to 1:5, more preferably 2:1 to 1:2, and especially 1.5:1 to 1:1. For calculations of such weight ratios, the total amount of cement is used. This means that if more than one type of cement is included, the sum of all cements is considered in the calculation. However, any additional pozzolanic materials or potential hydraulic materials that may be present are not included in the calculation.

[0029] The cementitious composition of the present invention contains an activator selected from alkali metal or alkaline earth metal salts of hydroxides, formates, chlorides, sulfates and / or nitrates. Salts of carbonates, bicarbonates or silicates are not preferred.

[0030] Highly preferred activators are calcium hydroxide, calcium formate, sodium chloride, sodium sulfate, and / or sodium nitrate. Such activators further contribute to improving the strength, especially the bond strength, of the cementitious compositions of the present invention.

[0031] According to the implementation scheme, the activator is selected from calcium hydroxide, calcium formate and / or sodium chloride.

[0032] Preferably, the activator is present in the cementitious composition of the present invention in an amount of 0.1-5% by weight, preferably 0.5-4% by weight, and more preferably 1.5-3.6% by weight, relative to the total dry weight of the hydraulic binder.

[0033] For the compositions of the present invention, it is preferable to additionally include a hydrophobic agent.

[0034] Hydrophobic agents can further contribute to improving the adhesive strength of the cementitious compositions of the present invention, especially the adhesive strength after water or heat storage.

[0035] Any hydrophobic agent known in the concrete or cement industry can be used. However, the preferred hydrophobic agent is selected from metal soaps, fatty acids and their salts, alkyl esters of fatty acids, vegetable oils, waxes, bitumen, organosilicones, oligomeric siloxanes, silanes, or mixtures thereof. Particularly preferred hydrophobic agents are metal salts of fatty acids, especially calcium, magnesium, or zinc salts of fatty acids, such as calcium stearate, magnesium stearate, zinc stearate, calcium oleate, magnesium oleate, and zinc oleate.

[0036] If a hydrophobic agent is present, it is used in the cementitious composition of the present invention in an amount of 0.5-5% by weight, preferably 1-2.5% by weight, relative to the total dry weight of the hydraulic binder.

[0037] The cementitious compositions of the present invention may additionally contain rheology modifiers selected from cellulose ethers and / or starch ethers.

[0038] The cellulose ether can be any of carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, and / or methyl hydroxypropyl cellulose. According to embodiments, the cellulose ether is selected from methyl hydroxypropyl cellulose or methyl hydroxyethyl cellulose. Most preferably, the cellulose ether, particularly methyl hydroxypropyl cellulose or methyl hydroxyethyl cellulose, has a viscosity of 150-180,000 mPas, or even more preferably 3,000-100,000 mPas, measured as a 2% solution in water at 20°C.

[0039] Starch ethers, especially hydroxypropyl starch ethers, may be additionally phosphorylated.

[0040] The cementitious composition of the present invention may additionally contain redispersible polymer powder.

[0041] The term "redispersible polymer powder" refers to a powder containing a polymer that forms a stable dispersion upon introduction into water. Redispersible polymer powders include not only the polymer but also typically mixtures thereof with, for example, protective colloids, emulsifiers, and carrier materials. Redispersible polymer powders can be manufactured, for example, by spray drying of a polymer dispersion, as described in patent application EP 1042391. Suitable redispersible powders are available, for example, under the trade name Vinnapas from Wacker Chemie AG.

[0042] For the context of this invention, it is preferred to use redispersible powders of synthetic organic polymers. The synthetic organic polymers in the context of this invention can be produced by free radical polymerization of monomers selected from ethylene, propylene, butene, isoprene, butadiene, styrene, acrylonitrile, acrylic acid, methacrylic acid, esters of acrylate, esters of methacrylic acid, vinyl esters, and vinyl chloride. Preferably, the synthetic polymer is a copolymer synthesized from two or more, preferably two different, monomers. The sequence of the copolymer can be alternating, block, or random. Preferred synthetic organic polymers are copolymers of vinyl acetate and ethylene, vinyl acetate and ethylene and methyl methacrylate, vinyl acetate and ethylene and ethylene ester, vinyl acetate and ethylene and acrylate, vinyl chloride and ethylene and vinyl lauryl ester, vinyl acetate and vinyl tert-carboxylic acid, acrylate and styrene, acrylate and styrene and butadiene, acrylate and acrylonitrile, styrene and butadiene, acrylic acid and styrene, methacrylic acid and styrene, styrene and acrylate, and styrene and methacrylate. The glass transition temperature (Tg) of the synthetic organic polymer can vary over a wide range. The Tg of a suitable synthetic organic polymer can be, for example, -50°C to +60°C, preferably -45°C to +35°C, and more preferably -25°C to +15°C.

[0043] According to some preferred embodiments, the cementitious composition of the present invention comprises a redispersible polymer powder selected from copolymers of vinyl acetate and ethylene and / or copolymers having a glass transition temperature of -5 to +15°C.

[0044] According to a preferred embodiment, the cementitious composition of the present invention comprises or consists of the following components (based on the dry weight of the cementitious composition, unless otherwise stated):

[0045] a) 20-40% by weight of a hydraulic binder comprising at least one cement and laterite in a weight ratio of 10:1-1:10, preferably 2:1-1:5, more preferably 2:1-1:2, and particularly 1.5:1-1:1.

[0046] b) At least one activator, selected from alkali metal or alkaline earth metal salts of hydroxides, formates, chlorides, sulfates and / or nitrates, relative to the total dry weight of the hydraulic binder, at a concentration of 0.1-5% by weight, preferably 0.5-4% by weight, more preferably 1.5-3.6% by weight, and based on the total dry weight of the hydraulic binder.

[0047] c) At least one hydrophobic agent, comprising 0.5-5% by weight, preferably 1-2.5% by weight, relative to the total dry weight of the hydraulic binder.

[0048] d) 50-78% by weight of aggregates and / or fillers, and

[0049] e) Optional additional additives.

[0050] Aggregates can be any material that is non-reactive in the hydration reaction of cementitious binders. Aggregates can be any aggregate commonly used in building materials. Typical aggregates include, for example, rock, crushed stone, crushed concrete, gravel, sand, especially quartz sand, river sand and / or manufactured sand, glass, expanded glass, hollow glass beads, glass ceramics, quarry waste, porcelain, fused or sintered abrasives, combustion supports, silica dry gel, and bio-based aggregates, such as hemp or sunflower aggregates. Sand is a particularly suitable aggregate.

[0051] The filler is characterized by its small particle size, particularly less than 0.063 mm. Specifically, the filler is selected from fine calcium carbonate, ground limestone, ground dolomite, ground alumina, and / or non-reactive slag. Non-reactive means that the slag used as filler does not react with water during hydration.

[0052] Particle size can be measured by sieving analysis, as described in standards such as ASTM C136 / C136M.

[0053] The additional additives are chemically different from the aforementioned activators, hydrophobic agents, rheology modifiers, and redispersible polymer powders. The additional additives are preferably selected from plasticizers and / or superplasticizers, aeration agents, defoamers, stabilizers, rheology modifiers, especially thickeners, water-reducing agents, accelerators, retarders, waterproofing agents, strength-enhancing additives, fibers, dust removers, foaming agents, pigments, corrosion inhibitors, biocides, and / or chromium (VI) reducing agents. Combining two or more of the aforementioned additional additives in a cementitious composition can be advantageous.

[0054] Laterite has a reddish color due to its high iron oxide content. Depending on the amount of laterite present, the cementitious compositions of the present invention also have a slightly reddish hue. Most cementitious compositions, especially mortars and concretes, are gray or white. Therefore, it is preferable to add pigments to the compositions of the present invention to achieve the desired color, particularly gray.

[0055] The increased amount of laterite present in the compositions of the present invention typically leads to an increased water requirement. Therefore, it is preferable to add suitable plasticizers, superplasticizers, and / or water-reducing agents to the compositions of the present invention.

[0056] The cementitious composition of the present invention is preferably a dry composition. Dry means that the water content in the cementitious composition of the present invention is less than 5% by weight, preferably less than 1% by weight, and particularly less than 0.1% by weight, relative to the total weight of the cementitious composition.

[0057] Before use, the cementitious composition of the present invention is mixed with water to provide a wet mixture. The amount of water used for mixing depends on factors such as the desired workability. Generally, a larger amount of water added will result in a more flowable wet mixture, while a smaller amount of water added will result in a stiffer wet mixture. A suitable weight ratio of water to the cementitious composition of the present invention is 0.15-1, preferably 0.2-0.6.

[0058] The hardening of the cementitious mixture of the present invention begins with the addition of water. Therefore, it is highly preferred to add water to the cementitious composition to produce a wet mixture shortly before the intended application of the wet mixture.

[0059] In another aspect, the present invention relates to a method for preparing a cementitious composition, comprising the following steps:

[0060] (i) Provides a hydraulic binder comprising 10-90% by weight, preferably 50-60% by weight, at least one type of cement and 10-90% by weight, preferably 40-50% by weight, laterite.

[0061] (ii) Provide an activator selected from alkali metal or alkaline earth metal salts of hydroxides, formates, chlorides, sulfates and / or nitrates, and

[0062] (iii) Mix and / or grind the hydraulic binder and the activator together.

[0063] The above features and implementation schemes also apply to this aspect.

[0064] The mixing in step (iii) can be carried out during the manufacture of the cementitious composition (e.g., dry mortar). However, the activator can also be dissolved or dispersed in water, preferably mixed in water, first, and then mixed with the hydraulic binder. In principle, the activator can also be mixed with other components of the cementitious composition (e.g., aggregates, fillers, or additional admixtures) first. This can be particularly preferred to minimize the number of additions during dry mortar manufacture.

[0065] The term "mutual grinding" refers to the process of co-grinding the activator with the hydraulic binder. Additives are added to the composition of the hydraulic binder before and / or during the grinding process.

[0066] They can be ground against each other on a friction mill. Particularly suitable friction mills are semi-autogenous mills and compression mills.

[0067] In this context, a compression mill is a type of mill capable of applying compressive force to a bed of materials to be ground. Preferably, the compressive force is applied by a rotating cylinder or rotor-stator. A compression mill can be, for example, a crusher or a roller mill. According to embodiments, the compression mill is a vertical roller mill, a horizontal roller mill, or a pot crusher, having controllable and adjustable compression. According to embodiments, in the method of the invention, mutual grinding is carried out in a vertical roller mill or a horizontal roller mill.

[0068] Semi-autogenous mills are, for example, ball mills or stirred mills. According to an embodiment, in the method of the present invention, the mutual grinding is carried out in a ball mill or stirred mill.

[0069] According to an embodiment, the method for preparing the cementitious composition of the present invention further includes the step of mixing and / or grinding the hydrophobic agent with the hydraulic binder and / or a mixture of the hydraulic binder and the activator.

[0070] In another aspect, the present invention relates to the use of cementitious compositions as claimed in any one of claims 1-12 as brick adhesives, particularly according to standard EN 12004:2017.

[0071] The above features and implementation schemes also apply to this aspect.

[0072] In particular, the cementitious composition of the present invention is used as a brick binder in the form of a wet mixture. The wet mixture is a mixture of the cementitious composition as described above and water as described above. The method of mixing the cementitious composition with water is not particularly limited and is known to those skilled in the art. Mixing can be continuous, semi-continuous, or batch mixing. Continuous mixing provides the advantage of high material throughput.

[0073] The wet mixture of the present invention can be applied by any means known to those skilled in the art. According to one embodiment, the wet mixture is applied by a trowel, brush, or roller. According to another embodiment, the wet mixture is applied by spray application. According to yet another embodiment, the wet mixture is poured from a suitable container. Spray application has the advantage of allowing for very rapid and continuous application. Those skilled in the art know suitable equipment for such spray applications.

[0074] The wet mixture of the present invention can be applied in a single layer or in multiple layers. Applying it in multiple layers has the advantage of achieving a higher overall layer thickness.

[0075] Before applying the wet mixture of the present invention, a primer may be applied to the substrate. The primer may also be applied between different layers of the wet mixture of the present invention during multi-layer application.

[0076] In another aspect, the present invention relates to a hardened body produced by hardening and curing the wet mixture of the present invention. The present invention particularly relates to hardened cementitious brick adhesives.

[0077] The following examples will provide those skilled in the art with other embodiments of the present invention. They are not intended to limit the invention in any way.

[0078] Example

[0079] Table 2 below provides an overview of the raw materials used.

[0080] Table 2: Raw Materials Used

[0081]

[0082] Example

[0083] The compositions given in Tables 3 and 4 below were prepared at 23°C and 50% RH. First, a dry mixture was prepared by weighing all ingredients except water into a Hobart N50 mixer and mixing at low speed for 2 minutes. The dry mixture was used without storage.

[0084] Weigh water into the mixing pan of the Hobart N50 mixer. Then, while stirring at low speed for 5-10 seconds, add the corresponding amount of dry mix. Adjust the water-to-dry powder weight ratio to achieve the appropriate viscosity. The weight ratios are given in Tables 3 and 4 below. Continue mixing at low speed for 30 seconds. Then stop mixing and clean the pan and paddle over 60 seconds. Then continue mixing at low speed for another 60 seconds. Then stop mixing and allow the mixture to mature for 3 minutes, then continue mixing for 15 seconds. The resulting mixture should be smooth and free of lumps.

[0085] Adhesive strength was measured according to DIN EN 1348:2007-11 after the time and aging shown in Tables 3 and 4 below.

[0086] Table 3: Compositions C-1 (comparative), E-1 to E-5 (invention) and results

[0087]

[0088] The results in Table 3 show that using a combination of OPC and laterite improves bond strength. Generally, a bond strength greater than 0.5 MPa is considered acceptable according to standard EN 12004:2017. It can also be seen that particularly good bond strength after water immersion is obtained at OPC:latite weight ratios of 1.5:1 and 1:1, while the bond strength after water immersion decreases at weight ratios of 1:2.3 or lower. Furthermore, it can be seen that particularly good bond strength after heat aging is obtained at OPC:latite weight ratios of 2.3:1 and 1.5:1, while the bond strength after heat aging decreases at weight ratios of 1:2.3 or lower.

[0089] Further comparative tests were conducted. Therefore, Example E-1 was repeated, but the laterite was replaced by bagasse ash (ash from bagasse calcined at 600-750°C, with a maximum particle size of 0.5 mm) at a 1:1 weight ratio and 1 g of calcium formate was added instead of 0.4 g. The bond strength after 7 days was measured to be 0.3 MPa. Despite the addition of a higher amount of activator and bagasse ash in the comparative example compared to Example E-1, the resulting bond strength was significantly lower. This result demonstrates the advantage of using virgin laterite in hydraulic binders compared to the use of biomass ash.

[0090] Table 4: Compositions E-6 to E-9 (Invention) and Results

[0091]

[0092] As can be seen from the results in Table 4 above, the addition of a hydrophobic agent can significantly improve the bond strength. This is especially true when the OPC:latreon weight ratio is 1.5:1 or lower.

Claims

1. A cementitious composition comprising or consisting of the following components: a) A hydraulic binder, comprising (in each case, relative to the total dry weight of the hydraulic binder) ai) 10-90% by weight, preferably 50-60% by weight of at least one type of cement. aii) 10-90% by weight, preferably 40-50% by weight of laterite. (b) At least one activator selected from alkali metal or alkaline earth metal salts of hydroxides, formates, chlorides, sulfates and / or nitrates.

2. The cementitious composition according to claim 1, characterized in that... The at least one type of cement is selected from Portland cement of type CEM I, CEM II, CEM III, CEM IV, or CEM V according to standard EN 197-1:2011, or a mixture thereof.

3. The cementitious composition according to any one of the preceding claims, characterized in that... The laterite is in an uncalcined form and contains 40-90% by weight, preferably 50-70% by weight, of aluminosilicates and 10-60% by weight, preferably 30-50% by weight, of iron oxides or the same.

4. The cementitious composition according to any one of claims 1 or 2, characterized in that... The laterite is in a calcined form and contains at least 40% by weight of calcined clay, especially metakaolinite, and at least 30% by weight of iron oxides, especially argumentite, hematite and / or magnetite.

5. The cementitious composition according to any one of the preceding claims, characterized in that... The weight ratio of cement to laterite in the hydraulic binder is 10:1 to 1:10, preferably 2:1 to 1:5, more preferably 2:1 to 1:2, and especially 1.5:1 to 1:

1.

6. The cementitious composition according to any one of the preceding claims, characterized in that... The activator is selected from calcium hydroxide, calcium formate and / or sodium chloride.

7. The cementitious composition according to any one of the preceding claims, characterized in that... The activator is present in an amount of 0.1-5% by weight, preferably 0.5-4% by weight, more preferably 1.5-3.6% by weight, relative to the total dry weight of the hydraulic binder.

8. The cementitious composition according to any one of the preceding claims, characterized in that... It additionally contains a hydrophobic agent, preferably selected from metal soaps, fatty acids and their salts, alkyl esters of fatty acids, vegetable oils, waxes, bitumen, organosilicon, oligomeric siloxanes, silanes or mixtures thereof.

9. The cementitious composition according to claim 8, characterized in that, The hydrophobic agent is present in an amount of 0.5-5% by weight, preferably 1-2.5% by weight, relative to the total dry weight of the hydraulic binder.

10. The cementitious composition according to any one of the preceding claims, characterized in that... It additionally contains a rheology modifier selected from cellulose ethers and / or starch ethers.

11. The cementitious composition according to any one of the preceding claims, characterized in that... It further comprises a redispersible polymer powder, preferably selected from copolymers of vinyl acetate and ethylene and / or copolymers with a glass transition temperature of -5°C to +15°C.

12. The cementitious composition according to any one of the preceding claims, characterized in that... It contains or is composed of the following components: a) 20-40% by weight of a hydraulic binder comprising at least one cement and laterite in a weight ratio of 10:1-1:10, preferably 2:1-1:5, more preferably 2:1-1:2, and particularly 1.5:1-1:

1. b) At least one activator, selected from alkali metal or alkaline earth metal salts of hydroxides, formates, chlorides, sulfates and / or nitrates, relative to the total dry weight of the hydraulic binder, at a concentration of 0.1-5% by weight, preferably 0.5-4% by weight, more preferably 1.5-3.6% by weight, and based on the total dry weight of the hydraulic binder. c) At least one hydrophobic agent, at 0.5-5% by weight, preferably 1-2.5% by weight, relative to the total dry weight of the hydraulic binder. d) 50-78% by weight of aggregates and / or fillers, and e) Optional additional additives.

13. A method for preparing a cementitious composition, comprising the following steps: (i) providing a hydraulic binder comprising 10-90% by weight, preferably 50-60% by weight, at least one type of cement and 10-90% by weight, preferably 40-50% by weight, laterite; (ii) providing an activator selected from alkali metal or alkaline earth metal salts of hydroxides, formates, chlorides, sulfates and / or nitrates; and (iii) mixing and / or grinding the hydraulic binder and the activator together.

14. The method according to claim 13, characterized in that, It further includes the steps of mixing and / or grinding the hydrophobic agent with the hydraulic binder and / or the mixture of the hydraulic binder and the activator.

15. Use of the cementitious composition according to any one of claims 1-12 as a brick adhesive, particularly in accordance with standard EN 12004:2017.

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