Alumina cement and calcium silicate-based two-component mortar system and its use

Abstract

A two-component mortar system for chemical fixation of fasteners in mineral substrates, comprising curing aqueous phase alumina cement component A and an initiator component B in the aqueous phase for initiating the curing process; further, a ready-to-use two-component system for chemical fixation of fasteners in mineral substrates such as brickwork, concrete, permeable concrete, or structures made of natural stone, preferably metal elements; and its use for chemical fixation of fasteners. [Solution] Component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked calcium silicate cement and water.

Description

Technical Field

[0001] The present invention relates to a two-component mortar system for chemical fixation of fastening means in a mineral substrate, comprising a curing-type aqueous alumina cement component A and an initiator component B in an aqueous phase for initiating the curing process, wherein component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked calcium silicate cement and water. Furthermore, the present invention relates to a ready-to-use two-component mortar system for chemical fixation of fastening means, preferably metal elements, in mineral substrates such as brickwork, concrete, permeable concrete, or structures made of natural stone, and to its use for chemical fixation of fastening means.

Background Art

[0002] There are many two-component mortar systems, sometimes referred to as kits-of-parts, in which each component is mixed before use or during application to initiate the curing process and is intended to provide good chemical fixation of the fastening means in the mineral substrate. For example, when rapid hardening is desired, an organic system based on a free-radical polymerizable resin is used. However, such systems are generally known to be polluting, expensive, and potentially dangerous and / or toxic to the environment and to those handling them, and they often need to be specially labeled. Furthermore, organic systems often show a significant decrease in stability when thermally exposed to strong sunlight or, alternatively, high temperatures, thereby reducing their mechanical performance with respect to the chemical fixation of the fastening means.

[0003] To overcome these drawbacks, alumina cement-based systems, primarily composed of minerals, have been developed. Alumina cement, with monocalcium aluminate as its main component, is widely used in the building and construction industries because the final product exhibits high levels of mechanical performance over long periods. Furthermore, alumina cement is resistant to bases, achieves maximum strength more quickly than Portland cement, and can withstand sulfate solutions. Therefore, alumina cement systems are preferred for use in the field of chemical fixation.

[0004] Furthermore, calcium aluminate slurry is known to provide high fire resistance to fixing points. However, compared to resin-based fixing mortars, such systems harden considerably slower, which often requires longer waiting times on site and disrupts the workflow. This is particularly important for fixing applications where immediate loading is crucial. In addition, calcium aluminate-based mortars contain the metastable hydrate phase CAH 10 Furthermore, due to the transformation of C2AH8 into the stable hydrate C3AH6, it undergoes conversion that leads to a decrease in performance over time. This is particularly pronounced in warm, humid environments, where the established metastable cement hydrate converts to a denser state, increasing porosity and ultimately degrading performance.

[0005] Blends of powdered ordinary Portland cement with calcium aluminate cement or calcium sulfoaluminate cement are known for the development of fast repair mortars. Since calcium aluminate cement is far more reactive than ordinary Portland cement, adding it in small amounts, such as about 10% of the total cement content, allows for shorter curing times and higher young-age strength, e.g., less than one day. However, commercially available fast repair products, such as Fastset repair mortar by Quikrete®, required on-site preparation by mixing powdered cement with a liquid phase.

[0006] European Patent No. 2162410 describes a ready-to-use two-component system comprising part A, based on aqueous alumina cement delayed with boric acid or a salt thereof, and part B, for initiating a curing process. The initiator in part B is made solely of a lithium salt. European Patent No. 0081385 also discloses a two-component system comprising an aqueous high-alumina cement composition with inhibited setting and a reactivator composition containing a lithium salt. European Patent No. 2794510 describes a stabilized aqueous suspension comprising alumina cement and / or calcium sulfoaluminate cement, which is inhibited by a phosphorus-containing compound and can be stored for a sufficient period of time even at high temperatures. This stabilized aqueous suspension may serve as a base for surface coatings.

[0007] However, these alumina-cement aqueous suspensions, delayed by boric acid or its salts, are often not very stable for sufficient storage time before use. Furthermore, boric acid is highly toxic and ecotoxic. Moreover, these modern systems require a high water-to-cement ratio and are characterized by their undesirable conversion, which reduces performance over time.

[0008] German Patent No. 2311239 describes an auxiliary composition for improving the setting and hardening properties of alumina cement and mortar, comprising lithium, a water-soluble lithium salt, and a hydroxylated organic acid or its salt or ester. This fluid may be directly incorporated into the alumina cement or mortar and concrete during their manufacture, or added to the mixed water during application. However, a drawback of this system is that the cement composition and activator composition cannot be stored for sufficient time to be ready for immediate use; therefore, they must be freshly prepared before use according to the desired setting and hardening time, resulting in more pre-application steps. Furthermore, the lithium-based activator component is expensive, and its extraction presents many problems from humanitarian, economic, and political standpoints.

[0009] Therefore, there is a need for a ready-to-use multi-component system, preferably a two-component system, that is superior to prior art systems in terms of environmental impact, health and safety, handling, storage time, sustainability, and a good balance between setting and hardening of the mortar. Furthermore, there is interest in providing a system that can be used to chemically fix adhesive means in a mineral substrate without adversely affecting the handling, properties, and mechanical performance of the chemical fixing system, and a system that increases performance over time by reducing the water-to-cement ratio and conversion used. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] In view of the above, the object of the present invention is to provide a multi-component system, in particular a two-component mortar system, that overcomes the shortcomings of the prior art systems. In particular, the object is to provide a two-component mortar system that is ready for immediate use, easy to handle, environmentally friendly, can be stored stably for a certain period before use, exhibits a good balance between setting and hardening, still possesses excellent mechanical properties with respect to chemically fixing the fixing means even under the influence of rising temperatures, and is further characterized by the ability to reduce the water-to-cement ratio and conversion.

[0011] Furthermore, an object of the present invention is to provide a two-component mortar system that can be used for chemical fixing of metal elements, preferably as a fixing means in mineral substrates such as structures made of brick, concrete, permeable concrete, or natural stone, and to provide a method for fixing said fixing means. [Means for solving the problem]

[0012] These and other objectives, which will become apparent from the description that ensures the invention is correct, are addressed by the invention as described in the independent claims. Dependent claims relate to preferred embodiments.

[0013] Summary of the Invention In one embodiment, the present invention provides a ready-to-use two-component mortar system comprising a curing aqueous phase alumina cement component A and an initiator component B in the aqueous phase for initiating a curing process, wherein component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked calcium silicate cement and water. In particular, component B comprises a siliceous clinker phase consisting of tricalcium silicate C3S, dicalcium silicate C2S, or a mixture thereof, and a blocking agent selected from the group consisting of monosaccharides, carboxylic acids, gluconic acid, glycolic acid, lignosulfonates, phosphoric acid, and phosphonic acid, their salts and esters, glucose, and mixtures thereof.

[0014] In another aspect, the present invention provides a two-component mortar system used for chemical fixing of metal elements, preferably as a fastening means in mineral substrates such as structures made of brick, concrete, permeable concrete, or natural stone; in another aspect, the present invention provides a method for fixing said fastening means and a method for fixing said fastening means. [Modes for carrying out the invention]

[0015] The following terms and definitions are used in the context of this invention.

[0016] When used in the context of this invention, the singular forms of "a" and "an" also include their respective plural forms unless otherwise explicitly indicated by the context. Therefore, the terms "a" or "an" are intended to mean "one or more" or "at least one" unless otherwise stated.

[0017] In the context of this invention, the term "alumina cement" refers primarily to calcium aluminate cement consisting of hydrated activated calcium aluminate. Other names include "high-alumina cement" or, in French, "Ciment fondu." The main active ingredient in calcium aluminate cement is monocalcium aluminate (CaAl2O4, CaO·Al2O3, or CA in cement chemical notation).

[0018] The term "silicic clinker phase" refers to tricalcium silicate (C3S) or dicalcium silicate (C2S), or mixtures thereof, which are the clinker phase of Portland cement clinker. Therefore, the silicic clinker phase essentially does not contain aluminate clinker phase and does not contain lime.

[0019] In the context of this invention, the term "initiator" refers to a compound or composition that modifies the chemical environment to initiate a specific chemical reaction. In this invention, the initiator modifies the pH value of the mortar suspension, thereby deblocking the hydraulic binder in the final mixture.

[0020] In the context of this invention, the terms “binder” or “binder component” refer to calcium-aluminate-based cementitious components and other additional optional components, such as fillers. In particular, the term “main binder component” refers to component A.

[0021] In the context of this invention, the term "water-to-cement ratio" refers to the ratio of (water) to (calcium aluminate cement and siliceous clinker phase), i.e., water / CAC+C2S, or water / CAC+C3S, or water / CAC+C2S+C3S.

[0022] Surprisingly, the inventors found that the two-component mortar system according to the present invention is an easy-to-handle, ready-to-use system for chemically fixing adhesive means in mineral substrates. In particular, it was found that a lower water-to-cement ratio can be used compared to state-of-the-art two-component injection mortars containing a filler-based activator component, with the aqueous slurry-based system containing a blocked alumina component as the main binder component and a blocked calcium silicate cement in an alkaline pH aqueous slurry as the second binder component. In addition, it was found that the long-term strength reduction due to conversion characteristic of calcium aluminate cement can be mitigated by blending these two cements to produce a stable calcium silicate hydrate phase and a portlandite hydrate phase.

[0023] While conventional calcium aluminate-based binders rely on synthetic or mined carbonate sources to mitigate strength loss due to conversion, calcium silicate cement can be used as a binder. By blocking the calcium silicate cement in water with sugars such as gluconates, an alkaline pH is achieved that can be used to activate the blocked calcium aluminate cement components. Therefore, separate activators such as sodium hydroxide or lithium hydroxide are not required. The alkaline pH generated from the hydration of the calcium aluminate cement subsequently activates the calcium silicate cement.

[0024] Furthermore, it has been found that the two-component mortar system of the present invention does not contain any harmful substances while maintaining standards for chemical bonding applications, thus also encompassing a reduction in labeling requirements.

[0025] The present invention relates to a two-component mortar system for chemically fixing fixing means in a mineral substrate, comprising a curing-type aqueous alumina cement component A and an initiator component B in an aqueous phase for initiating the curing process. In particular, component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked calcium silicate cement and water.

[0026] Component A according to the present invention is based on calcium aluminate cement (CAC) or calcium sulfoaluminate cement (CAS) in an aqueous phase. The calcium aluminate cement that can be used in the present invention is characterized by rapid setting and rapid hardening, rapid drying and shrinkage compensation when mixed with calcium sulfate, excellent corrosion resistance and shrinkage resistance. Such a calcium aluminate cement suitable for use in the present invention is, for example, Ternal® White (Kerneos, France).

[0027] When component A contains a mixture of calcium aluminate cement (CAC) and calcium sulfate (CaSO4), rapid ettringite formation occurs during hydration. In concrete chemistry, the reaction of calcium aluminate and calcium sulfate forms calcium hexaluminate trisulfate hydrate represented by the general formula (CaO)6(Al2O3)(SO3)3·32H2O or (CaO)3(Al2O3)(CaSO4)3·32H2O, resulting in rapid setting and hardening and even shrinkage compensation or expansion. By moderately increasing the sulfate content, shrinkage compensation can be achieved.

[0028] Component A of the present invention comprises, based on the total weight of component A, at least about 40% by weight, preferably at least about 50% by weight, more preferably at least about 60% by weight, most preferably at least about 70% by weight, about 40% to about 95% by weight, preferably about 50% to about 90% by weight, more preferably about 60% to about 85% by weight, and most preferably about 70% to about 80% by weight of calcium aluminate cement.

[0029] According to an alternative embodiment of the present invention, component A comprises, based on the total weight of component A, at least about 20% by weight, preferably at least about 30% by weight, more preferably at least about 40% by weight, most preferably at least at least about 50% by weight, about 20% to about 80% by weight, preferably about 30% to about 70% by weight, more preferably about 35% to about 60% by weight, most preferably about 40% to about 55% by weight of alumina cement, and, based on the total weight of component A, at least about 5% by weight, preferably at least at least 10% by weight, more preferably at least at least 15% by weight, most preferably at least at least 20% by weight, about 1% to about 50% by weight, preferably about 5% to about 40% by weight, more preferably about 10% to about 30% by weight, most preferably about 15% to about 25% by weight of calcium sulfate, preferably calcium sulfate hemihydrate. In a preferred alternative embodiment of the two-component mortar system of the present invention, the CaSO4 / CAC ratio of component A should be 35:65 or less.

[0030] The blocking agent contained in component A according to the present invention is selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, preferably phosphoric acid or metaphosphoric acid, most preferably phosphoric acid, in particular an 85% aqueous solution of phosphoric acid. Component A contains, based on the total weight of component A, at least about 0.1% by weight, preferably at least about 0.3% by weight, more preferably at least about 0.4% by weight, most preferably at least about 0.5% by weight, about 0.1% to about 20% by weight, preferably about 0.1% to about 15% by weight, more preferably about 0.1% to about 10% by weight, and most preferably about 0.3% to about 10% by weight of the blocking agent. In a preferred embodiment, component A contains, based on the total weight of component A, about 0.3% to about 10% by weight of an 85% aqueous solution of phosphoric acid.

[0031] In advantageous embodiments, component A further comprises the following properties, either alone or in combination:

[0032] Component A may additionally contain a plasticizer. The plasticizer may be selected from the group consisting of flowlubrication agents from the families of low molecular weight (LMW) polyacrylic acid polymers, polyphosphonate polyoxes and polycarbonate polyoxes, and Ethacryl flowlubrication agents from the polycarboxylate ether group, and mixtures thereof, for example, Ethacryl® G (Coatex, Arkema Group, France), Acumer® 1051 (Rohm and Haas, UK), or Sika® ViscoCrete®-20 HE (Sika, Germany). Suitable plasticizers are commercially available products. Component A may contain, based on the total weight of component A, at least about 0.2% by weight, preferably at least about 0.3% by weight, more preferably at least about 0.4% by weight, most preferably at least about 0.5% by weight, about 0.2% to about 20% by weight, preferably about 0.3% to about 15% by weight, more preferably about 0.4% to about 10% by weight, and most preferably about 0.5% to about 5% by weight of the plasticizer.

[0033] Component A may additionally contain a thickening agent. The thickening agents that can be used in the present invention may be selected from the group consisting of xanthan gum, gellan gum or DIUTAN® gum (CPKelko, USA), mineral products such as starch-derived ethers, guar-derived ethers, polyacrylamide, carrageenan, agar, and clay, and organic products such as mixtures thereof. Suitable thickening agents are commercially available products. Component A contains, based on the total weight of Component A, at least about 0.01% by weight, preferably at least about 0.1% by weight, more preferably at least about 0.2% by weight, most preferably at least about 0.3% by weight, about 0.01% to about 10% by weight, preferably about 0.1% to about 5% by weight, more preferably about 0.2% to about 1% by weight, most preferably about 0.3% to about 0.7% by weight of the thickening agent.

[0034] Component A may further contain an antimicrobial agent or biocide. The antimicrobial agent or biocide that can be used in the present invention may be selected from the group consisting of compounds of the isothiazolinone family, such as methylisothiazolinone (MIT), octylisothiazolinone (OIT), and benzoisothiazolinone (BIT), and mixtures thereof. Suitable antimicrobial agents or biocides are commercially available products. Ecocide K35R (Progiven, France) and Nuosept OB 03 (Ashland, The Netherlands) are mentioned as examples. Component A contains, based on the total weight of Component A, at least about 0.001% by weight, preferably at least about 0.005% by weight, more preferably at least about 0.01% by weight, most preferably at least about 0.015% by weight, about 0.001% to about 1.5% by weight, preferably about 0.005% to about 0.1% by weight, more preferably about 0.01% to about 0.075% by weight, and most preferably about 0.015% to about 0.03% by weight of the antimicrobial agent or biocide. In a preferred embodiment, Component A contains, based on the total weight of Component A, about 0.015% to about 0.03% by weight of Nuosept OB 03.

[0035] Component A may further contain at least one mineral-based filler. Mineral-based fillers that can be used in the present invention may be limestone fillers, for example, calcite, sand, corundum, dolomite, alkali-resistant glass, crushed stone, gravel, pebbles, quartz, quartz powder, quartz sand, clay, fly ash, fumed silica, brick powder, rice peel ash, phonolite, calcined clay and metakaolin, carbonate compounds, pigments, titanium dioxide, lightweight fillers, or mixtures thereof. Suitable fillers are commercially available products. Component A may contain at least about 1% by weight, preferably at least about 2% by weight, more preferably at least about 5% by weight, and most preferably at least about 8% by weight of the at least one filler, based on the total weight of component A.

[0036] The water content of component A is, based on the total weight of component A, at least about 1% by weight, preferably at least about 5% by weight, more preferably at least about 10% by weight, most preferably at least about 20% by weight, about 1% to about 50% by weight, preferably about 5% to about 40% by weight, more preferably about 10% to about 30% by weight, and most preferably about 15% to about 25% by weight.

[0037] The presence of plasticizers, thickeners, antimicrobial agents, biocides, or fillers does not alter the overall inorganic nature of cementitious component A.

[0038] Component A, which contains calcium aluminate cement or calcium sulfoaluminate cement, is present in the aqueous phase, preferably in the form of a slurry or paste.

[0039] The initiator component B of this invention comprises blocked calcium silicate cement and water.

[0040] The blocked calcium silicate cement of component B contains calcium silicate cement and a blocking agent.

[0041] In particular, the blocked calcium silicate cement contains a siliceous clinker phase consisting of tricalcium silicate C3S, dicalcium silicate C2S, or a mixture thereof, and preferably the blocked calcium silicate cement is tricalcium silicate C3S or dicalcium silicate C2S. In the most preferred embodiment, the calcium silicate cement is tricalcium silicate C3S or dicalcium silicate C2S that does not contain an aluminate clinker phase and does not contain lime, and most preferably, tricalcium silicate C3S that does not contain an aluminate clinker phase and does not contain lime.

[0042] Component B of the present invention comprises, based on the total weight of component B, at least about 5% by weight, preferably at least about 10% by weight, more preferably at least about 20% by weight, most preferably at least about 30% by weight, about 5% to about 95% by weight, preferably about 10% to about 90% by weight, more preferably about 20% to about 80% by weight, and most preferably about 30% to about 75% by weight of calcium silicate cement.

[0043] The blocking agent for calcium silicate cement is selected from the group consisting of monosaccharides, carboxylic acids, gluconic acid, glycolic acid, lignosulfonates, phosphoric acid, and phosphonic acid, their salts and esters, glucose, and mixtures thereof, preferably glucose or sodium gluconate, and most preferably sodium gluconate.

[0044] Component B contains, based on the total weight of component B, at least about 0.01% by weight, preferably at least about 0.05% by weight, more preferably at least about 0.1% by weight, most preferably at least about 1.0% by weight, about 0.01% to about 25% by weight, preferably about 0.05% to about 20% by weight, more preferably about 0.1% to about 15% by weight, and most preferably about 1.0% to about 10% by weight of the blocking agent. In the most preferred embodiment, component B contains, based on the total weight of component B, about 0.01% to about 0.4% by weight of sodium gluconate.

[0045] The ratio of blocking agent:C3S is preferably 1:300, more preferably 1:500, and most preferably 1:1000.

[0046] The water content of component B is, based on the total weight of component B, at least about 1% by weight, preferably at least about 5% by weight, more preferably at least about 10% by weight, most preferably at least about 20% by weight, about 1% to about 60% by weight, preferably about 5% to about 50% by weight, more preferably about 10% to about 40% by weight, and most preferably about 15% to about 30% by weight.

[0047] In advantageous embodiments, component B, either alone or in combination, further comprises the following properties:

[0048] Component B may additionally contain a thickening agent. The thickening agent used in the present invention may be selected from the group consisting of bentonite, silicon dioxide, quartz, acrylate-based thickening agents such as alkali-soluble or alkali-swelling emulsions, fumed silica, clay, and titanate chelating agents. Polyvinyl alcohol (PVA), hydrophobically modified alkali-soluble emulsion (HASE), hydrophobically modified ethylene oxide urethane polymers known in the art as HEUR, and cellulosic thickeners, such as hydroxymethyl cellulose (HMC), hydroxyethyl cellulose (HEC), hydrophobically-modified hydroxyethyl cellulose (HMHEC), sodium carboxymethyl cellulose (SCMC), sodium carboxymethyl 2-hydroxyethyl cellulose, 2-hydroxypropyl methylcellulose, 2-hydroxyethyl methylcellulose, 2-hydroxybutyl methylcellulose, 2-hydroxyethyl ethylcellulose, 2-hydroxypropyl cellulose, attapulgite clay, and mixtures thereof are exemplified. Suitable thickeners include commercially available products such as Optigel WX (BYK-Chemie GmbH, Germany), Rheolate 1 (Elementis GmbH, Germany), Cellosize (trademark), and Acrysol ASE-60 (The Dow Chemical Company).Component B contains, based on the total weight of component B, at least about 0.01% by weight, preferably at least about 0.05% by weight, more preferably at least about 0.1% by weight, most preferably at least about 0.3% by weight, about 0.01% to about 15% by weight, preferably about 0.05% to about 10% by weight, more preferably about 0.1% to about 5% by weight, and most preferably about 0.1% to about 1% by weight of the thickening agent.

[0049] Component B may additionally contain a plasticizer. The plasticizer may be selected from the group consisting of flowables from the families of low molecular weight (LMW) polyacrylic acid polymers, polyphosphonate polyoxes and polycarbonate polyoxes, and Ethacryl flowables from the polycarboxylate ether group, and mixtures thereof, for example, Ethacryl® G (Coatex, Arkema Group, France), Acumer® 1051 (Rohm and Haas, UK), or Sika® ViscoCrete®-20 HE (Sika, Germany). Suitable plasticizers are commercially available products. Component B may contain, based on the total weight of component B, at least about 0.2% by weight, preferably at least about 0.3% by weight, more preferably at least about 0.4% by weight, most preferably at least about 0.5% by weight, about 0.2% to about 20% by weight, preferably about 0.3% to about 15% by weight, more preferably about 0.4% to about 10% by weight, and most preferably about 0.5% to about 5% by weight of the plasticizer.

[0050] Component B may optionally contain at least one mineral filler. Mineral fillers that can be used in the present invention may include limestone fillers, e.g., calcite, sand, corundum, dolomite, alkali-resistant glass, crushed stone, gravel, medium gravel, quartz, quartz powder, quartz sand, clay, fly ash, fumed silica, brick powder, rice husk ash, phonolite, calcined clay and metakaolin, carbonate compounds, pigments, titanium dioxide, lightweight fillers, or mixtures thereof. Suitable fillers are commercially available products. Component B may contain at least about 1% by weight, preferably at least about 10% by weight, more preferably at least about 20% by weight, and most preferably at least about 30% by weight of the at least one filler, based on the total weight of component B. The at least one mineral filler contained in component B according to the present invention is preferably a mixture of mineral fillers. The at least one mineral filler is selected to obtain particle sizes complementary to the alumina cement and calcium silicate cement.

[0051] The presence of plasticizers and thickeners does not alter the overall inorganic nature of component B.

[0052] Component B, which contains blocked calcium silicate cement, is present in the aqueous phase, preferably in the form of a slurry or paste.

[0053] Furthermore, component A and / or component B may contain an accelerator component. The accelerator component consists of at least one alkali and / or alkaline earth metal salt selected from the group consisting of hydroxides, chlorides, sulfates, phosphates, monohydrogen phosphates, dihydrogen phosphates, nitrates, carbonates, and mixtures thereof. Preferably, the accelerator component is an alkali or alkaline earth metal salt, more preferably a water-soluble alkali or alkaline earth metal salt, more preferably a calcium metal salt such as calcium hydroxide, calcium sulfate, calcium carbonate, calcium chloride, calcium formate, or calcium phosphate; a sodium metal salt such as sodium hydroxide, sodium sulfate, sodium carbonate, sodium chloride, sodium formate, or sodium phosphate; or a lithium metal salt such as lithium hydroxide, lithium sulfate, lithium sulfate monohydrate, lithium carbonate, lithium chloride, lithium formate, or lithium phosphate, most preferably lithium sulfate or lithium sulfate monohydrate. Component A and / or B each contain, based on the total weight of component A or B, at least about 0.01% by weight, preferably at least about 0.05% by weight, more preferably at least about 0.1% by weight, most preferably at least about 1.0% by weight, about 0.01% to about 25% by weight, preferably about 0.05% to about 20% by weight, more preferably about 0.1% to about 15% by weight, and most preferably about 1.0% to about 10% by weight of the accelerator.

[0054] The pH value of component B is preferably greater than 10, more preferably greater than 11, most preferably greater than 12, and especially preferably in the range of 10 to 14, and more preferably in the range of 11 to 13.

[0055] In the most preferred embodiment, component A comprises or consists of the following components: 70-80% by weight calcium aluminate cement, 0.5-1.5% by weight of phosphoric acid, 0.5-1.5% by weight of a thickening agent, 0.5-1.5% by weight of plasticizer, 0.001 to 0.05% by weight of an antibacterial or biocide agent, 15-25% by weight of water.

[0056] In the most preferred embodiment, component B comprises or consists of the following components: 45% to 85% by weight calcium silicate cement, 0.01 to 0.5% by weight of sodium gluconate, and 10% to 35% by weight of water.

[0057] In the most preferred embodiment, component B comprises or consists of the following components: C3S containing 45% to 85% by weight, which does not contain aluminate clinker phase and does not contain lime. 0.01 to 0.5% by weight of sodium gluconate, and 10% to 35% by weight of water.

[0058] Component A of the present invention can be prepared as follows: Mix a phosphorus-containing blocking agent with water so that the pH of the resulting mixture is approximately 2. Add a plasticizer and homogenize the mixture. Premix alumina cement, optionally calcium sulfate, and optionally mineral filler, and gradually add them to the mixture while increasing the stirring speed so that the pH of the resulting mixture is approximately 4. Finally, add a thickener, an antimicrobial / biocide agent, and optionally an accelerator component, and mix until the mixture is completely homogenized.

[0059] Component B of the present invention can be prepared as follows: Mix calcium silicate cement and blocking agent with water until the mixture is homogeneous. Finally, fillers, thickeners and plasticizers, and accelerator components may be optionally added until the mixture is completely homogeneous.

[0060] Components A and B exist in the aqueous phase, preferably in the form of a slurry or paste. In particular, components A and B have a paste-like or fluid appearance depending on their respective compositions. In one preferred embodiment, components A and B are in the form of a paste to prevent sagging when the two components are mixed.

[0061] The weight ratio (A / B) between component A and component B is preferably between 7 / 1 and 1 / 3, and more preferably 3 / 1. Preferably, the composition of the mixture includes 75% by weight of component A and 25% by weight of component B. In an alternative embodiment, the composition of the mixture includes 25% by weight of component A and 75% by weight of component B.

[0062] This two-component system is mineral-based and is not affected by the presence of additional thickeners or other agents.

[0063] The shelf life of this two-component system depends on the individual shelf life of each component, with components A and B having a shelf life of at least 6 months at ambient temperature to protect the system from delays in storage and supply. Most preferably, components A and B are individually stable for at least 6 months. Components A and B were stored in sealed containers at 20°C to avoid evaporation of water, and their fluidity, homogeneity, whether sedimentation occurred, and any changes in pH value after several time intervals were examined. Since the properties of all components remained unaffected after 6 months, the shelf life is at least 6 months at 20°C.

[0064] After mixing the two components A and B, it is preferable that the two-component mortar system has an initial setting time of at least 5 minutes, preferably at least 10 minutes, more preferably at least 15 minutes, most preferably at least 20 minutes, and in particular in the range of about 5 to 25 minutes, preferably in the range of about 10 to 20 minutes.

[0065] In multi-component mortar systems, particularly two-component mortar systems, the volume ratio of cementitious component A to initiator component B is 1:1 to 7:1, preferably 3:1. In alternative embodiments, the volume ratio of cementitious component A to initiator component B is 1:3 to 1:2.

[0066] After being produced separately, components A and B are introduced into separate containers, from which they are discharged by mechanical devices and led through a mixing device. The two-component mortar system of the present invention is preferably a ready-to-use system, in which components A and B are arranged separately from each other in a multi-chamber device such as a multi-chamber cartridge and / or multi-chamber cylinder, or in a two-component capsule, preferably in a two-chamber cartridge or two-component capsule. The multi-chamber system preferably includes two or more foil bags for separating curing component A and initiator component B. The contents of the chambers or bags, which are mixed together by a mixing device, preferably via a static mixer, can be injected into a borehole. It is also possible to assemble in a set of multiple chamber cartridges or pails or buckets.

[0067] The hardening alumina cement composition, as appropriate, is required to fix the fastening means and is initially inserted directly into the boreholes initially introduced into the mineral substrate during the chemical fixation of the fastening means. After that, the building elements to be fixed, such as anchor rods, are inserted and adjusted, and then the mortar composition sets and hardens. In particular, the two-component system of the present invention is considered a chemical anchor for fixing fastening means, especially metal elements.

[0068] The two-component mortar system of the present invention can be used as a fastening means in mineral substrates such as brickwork, concrete, permeable concrete, or structures made of natural stone, preferably for the chemical fastening of metal elements such as anchor rods, especially threaded rods, bolts, and steel reinforcements. In particular, the two-component mortar system of the present invention can be used for the chemical fastening of fastening means such as metal elements in boreholes. It can be used for fastening purposes that involve increased load capacity at temperatures above room temperature or during heating, for example above 80°C, and / or increased bond strength stress during curing.

[0069] In particular, the two-component mortar system of the present invention is used in a method for chemically fixing a fixing means in a mineral substrate, and this method includes the steps of introducing a borehole into a mineral substrate, mixing component A and component B to obtain a hardenable alumina cement composition, directly inserting the alumina cement composition into the borehole, inserting and adjusting the building elements to be fixed, and hardening and setting the alumina cement composition.

[0070] Furthermore, the two-component mortar system of the present invention may be used for coating, or in particular for attaching fibers, scrim, cloth, or composite materials, especially highly elastic fibers, preferably carbon fibers, for reinforcement of building structures, such as walls, ceilings, or floors, or even for installing components such as plates or blocks made of stone, glass, or plastic onto buildings or structural elements.

[0071] The following examples illustrate the present invention, but do not limit it thereto. [Examples]

[0072] 1. Preparation of Component A and Component B First, cementitious component A and initiator component B are produced by mixing the components specified in Tables 1 and 2, respectively. The given proportions are expressed in weight percent.

[0073] Specifically, 19.86 grams of deionized water, 0.75 grams of 85% phosphoric acid (blocking agent), 0.6 grams of Ethacryl G (high-flow agent), and 0.015 grams of Nuosept® (biocide) were homogenized at room temperature. While stirring in a dissolving machine, calcium aluminate cement (78.28 grams, pure Ternal White®) was added in small amounts sequentially until a smooth liquid paste slurry of blocked cement in water with a pH of less than 7 was obtained. After adding the calcium aluminate cement, 0.5 grams of xanthan gum (thickener) was added, and the slurry was homogenized at 2000 rpm for 5 minutes.

[0074] [Table 1]

[0075] An exemplary preparation of component B was as follows: Tricalcium silicate (C3S), water, and sodium gluconate were mixed and homogenized. The pH of the blocked silicate slurry was approximately 12.

[0076] [Table 2]

[0077] 2. Calorimetry and Observation Mixtures of silicate mortar and aluminate mortar were prepared to vary the C3S / CA ratio according to Table 3. Extra water was added to fix the water / (C3S+CA) ratio at 0.4, and the mortars were mechanically mixed in a high-speed mixer. Details of the mixtures, the weight ratios of the two slurries A:B, and their overall C3S:CAC ratios are shown in Table 3.

[0078] [Table 3]

[0079] The potential for reactivating the cement binder by combining two blocked systems is measured by the thermal output of hydration. Since the dissolution of the clinker phase is exothermic, measuring the thermal output is preferable for tracking hydration. All lumps remained hard until the end of the test (7 days), indicating they could be used for fixing the adhesive. The thermal outputs are summarized in Table 4.

[0080] [Table 4]

[0081] Table 4 shows the effect of the amount of blocking agent (sodium gluconate) added on the total thermal output of the C3S-rich blend. Comparing Example 3 to Example 5 and Example 4 to Example 6 with a fixed C3S / CAC ratio, it can already be seen that increasing the amount of blocking agent reduced the thermal output by the 7th day of hydration. This means that fewer reactions occurred during that period, resulting in a lower load value at a young age. Comparing Example 3 to Example 4 and Example 5 to Example 6 with a fixed blocking agent / C3S ratio, increasing the C3S fraction in the system reduces the thermal output of the mortar. However, the heat increases and the mass hardens.

[0082] Table 4 also shows the thermal output of mortars with blends that varied the ratio of C3S to CAC, with the C3S content ranging from 85% to 15%. For blends containing 85% C3S, the lowest thermal output was recorded by day 7. Replacing the C3S fraction with the calcium aluminate fraction resulted in a continuous increase in thermal output up to day 7.

[0083] As shown above, the two-component mortar system of the present invention provides curing speed and mechanical strength comparable to systems known in the art, but its essentially mineral composition makes it far less toxic than known systems of the prior art, resulting in significantly less environmental pollution and enabling cost-effective production.

[0084] Furthermore, it was shown that a system based on an aqueous slurry containing a blocked alumina component as the main binder component and a blocked calcium silicate cement in an alkaline pH aqueous slurry as the second binder component allows for a lower water-to-cement ratio compared to the latest two-component injection mortars containing a filler-based activator component. In addition, it was shown that the long-term strength reduction due to conversion characteristic of calcium aluminate cement can be mitigated by blending these two cements to produce stable hydrates, the calcium silicate hydrate phase and the portlandite phase.

[0085] Furthermore, the two-component mortar system of the present invention has been shown to contain no harmful substances while maintaining standards for chemical bonding applications, thus also encompassing a reduction in labeling requirements.

Claims

1. A two-component mortar system comprising a curing-type aqueous phase alumina cement component A and an initiator component B in the aqueous phase for initiating the curing process, wherein component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked calcium silicate cement and water.

2. The two-component mortar system according to claim 1, wherein the blocked calcium silicate cement comprises calcium silicate cement, and the blocking agent for the calcium silicate cement is selected from the group consisting of monosaccharides, carboxylic acids, gluconic acid, glycolic acid, lignosulfonates, phosphoric acid, and phosphonic acid, salts and esters thereof, glucose, and mixtures thereof.

3. The two-component mortar system according to claim 2, wherein the calcium silicate cement is present in an amount ranging from about 10% by weight to about 80% by weight based on the total weight of component B.

4. The two-component mortar system according to claim 2 or 3, wherein the blocking agent for the calcium silicate cement is present in an amount ranging from about 0.01% by weight to about 10% by weight based on the total weight of component B.

5. The two-component mortar system according to any one of claims 2 to 4, wherein the blocking agent is sodium gluconate.

6. The calcium silicate cement is tricalcium silicate C, which is the siliceous clinker phase. ３ S, Dicalcium Silicate C ２ A two-component mortar system according to any one of claims 2 to 5, comprising S, or a mixture thereof.

7. The calcium silicate cement described above does not contain an aluminate clinker phase and does not contain lime, most preferably it does not contain an aluminate clinker phase and does not contain lime, and is tricalcium silicate C ３ A two-component mortar system according to any one of claims 2 to 6, wherein S.

8. A two-component mortar system according to any one of claims 1 to 7, wherein the shelf life of component A and component B is at least six months.

9. A two-component mortar system according to any one of claims 1 to 8, wherein component A and component B are in the form of a slurry or paste.

10. A two-component mortar system according to any one of claims 1 to 9, wherein the pH value of component B exceeds 11.

11. Component B is, Aluminate clinker phase-free and lime-free, containing 45% to 85% by weight of C ３ S and, 0.01 to 0.5% by weight of sodium gluconate, A two-component mortar system according to any one of claims 1 to 10, comprising 10% to 35% by weight of water.

12. Use of a two-component mortar system according to any one of claims 1 to 11 for chemically fixing an adhesive means in a mineral substrate.

13. The use according to claim 12, wherein the fastening means is a metal element, preferably an anchor rod, a threaded anchor rod, a bolt, or a steel reinforcement.

14. The use according to claim 12 or 13, wherein the mineral substrate is a structure made of brickwork, concrete, permeable concrete, or natural stone.

15. A method for chemically fixing an adhesive means in a mineral substrate, characterized in that a two-component mortar system is used, comprising a curing aqueous phase alumina cement component A and an initiator component B in the aqueous phase for initiating a curing process, wherein component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked calcium silicate cement and water, and the method is characterized in that - The process of introducing boreholes into a mineral substrate, - A step of mixing component A and component B to obtain a hardening alumina cement composition, - A step of directly inserting this alumina cement composition into the bore hole, - The process of inserting and adjusting fixed building elements, A method comprising the step of hardening and setting the alumina cement composition.

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