Use of at least one alkali metal salt and / or alkaline earth metal salt in aluminous-cement-based inorganic cement mortar system for acceleration of hardening of cement in chemical fastening

Abstract

To provide a method of chemical fastening by acceleration of hardening of cement in chemical fastening, for giving continuity possibility and reducing harmful substance in application areas of a final inorganic fastening system.SOLUTION: In a use of at least one alkali metal salt and / or an alkaline earth metal salt in an inorganic cement mortar system for chemical fastening of fastening means in a mineral base material (fastening target material) for acceleration of hardening of cement, a hardenable aluminous cement component A and an initiator component B for initiation of hardening processing are included, the aluminous cement component A is an aluminous cement component based on a water phase calcium aluminate cement, the component A further includes at least one blocking agent consisting of a group selected from phosphoric acid, metaphosphoric acid, phosphorous acid, boric acid, and phosphonic acid, and the initiator component B further includes at least one retarder, at least one mineral filler, and water.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to the use of at least one alkali metal salt and / or alkaline earth metal salt in an inorganic mortar system for the chemical (adhesive-based) fastening of fastening means in mineral substrates, comprising a settable alumina cement component A and an initiator component B for starting the hardening process, wherein component A further comprises at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid, boric acid and phosphonic acid, and component B comprises an activator. In particular, the present invention relates to the use of at least one alkali metal salt and / or alkaline earth metal salt in an inorganic mortar system for the chemical (adhesive-based) fastening of fastening means in mineral substrates to accelerate the hardening of the cement. Furthermore, the present invention relates to a method for the chemical (adhesive-based) fastening of fastening means, preferably metal elements, in mineral substrates such as brickwork, concrete, permeable concrete or structures made of natural stone. [Background technology]

[0002] Many mortar systems exist that provide good chemical (adhesive) fastening of fastening means in mineral substrates. For example, when fast hardening is desired, organic systems based on free-radical polymerizable resins are used. However, such systems are generally known to be polluting, expensive, potentially dangerous, and / or toxic to the environment and to those who handle them, and they often require special warning labels. Furthermore, organic systems often show a significant decrease in stability when exposed to strong sunlight or otherwise to high temperatures, such as fire, thereby reducing their mechanical performance with respect to the chemical fastening of fastening means.

[0003] To overcome these drawbacks, mineral systems based primarily on alumina cement have been developed. Alumina cement has monocalcium aluminate as its main component and is widely used in the building and construction industry because the final product exhibits high levels of mechanical performance over time. Alumina cement is also resistant to bases, achieves maximum strength more quickly than Portland cement, and can withstand sulfate solutions. Therefore, alumina cement systems are preferably used in the field of chemical fastening.

[0004] With regard to chemical fastening of fastening means in mineral substrates, most of the known systems lack sufficient fluidity for the practical use of the resulting compositions.In many cases, such prior art compositions also tend to crack in a relatively short time or do not exhibit the required mechanical performance under certain conditions, such as under the influence of high temperatures, in diamond drilled holes, or in wet drilled holes, as well as over long periods of time.In addition, known systems tend to exhibit significant shrinkage when applied to drilled holes, thereby resulting in insufficient fastening of the fastening means.

[0005] Furthermore, there is a need to significantly accelerate the setting of cement, as this would speed up construction at building sites and thereby save valuable labor hours. In addition, there is a need to reduce warning labeling by reducing harmful substances, such as carcinogenic, toxic, mutagenic or environmentally hazardous substances, in fastening systems, such as peroxides, reactive diluents and resins, in order to improve handling safety during production and for workers, and during transportation, and to reduce costs of product logistics and storage.

[0006] There is also an increasing need for sustainable binders in fastenings: the use of less limited resources in fastening systems is more sustainable compared to currently available systems, in particular Portland cement-based and aluminate cement-based systems also have a lower carbon footprint or lower global warming potential, respectively, than synthetic resins or components whose availability is limited due to their resource considerations.

[0007] Therefore, there is a need for an inorganic mortar system, preferably a two-component inorganic mortar system, that is superior to the systems of the prior art.In particular, it is important to provide a system that can be used for chemical fastening of fastening means in mineral substrates, without adversely affecting the handling, characteristics, and mechanical performance of chemical (adhesive) fastening systems, especially when applied to diamond drilling, wet drilling, and over a long period of time.In particular, there is a need for a system that accelerates the hardening of cement compared to known systems.In addition, there has long been a need to use fewer components with limited resources in fastening systems, thereby addressing sustainability and simultaneously reducing carbon footprint. Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide an inorganic mortar system, preferably a multi-component mortar system, in particular a two-component inorganic mortar system, which has excellent mechanical performance under certain conditions, in particular in diamond drilled holes, in wet drilled holes and over long periods of time, while at the same time having increased load values and accelerated hardening of the cement compared to known systems.

[0009] Furthermore, it is an object of the present invention to provide a method for the chemical fastening of fastening means, preferably metal elements, in mineral substrates such as brickwork, concrete, permeable concrete or structures made of natural stone, using the inorganic mortar system described above.

[0010] It is also an object of the present invention to provide the use of at least one alkali metal salt and / or alkaline earth metal salt in inorganic mortar systems to accelerate the hardening of cement in chemical fastenings, providing sustainability and reducing harmful substances in the application area of the final inorganic fastening system. [Means for solving the problem]

[0011] As will become apparent from the detailed description of the invention, these and other objects are solved by the invention as set forth in the independent claims. The dependent claims relate to preferred embodiments of the invention.

[0012] In one aspect, the invention relates to the use of at least one alkali metal salt and / or alkaline earth metal salt in an inorganic mortar system for the chemical (adhesive) fastening of fastening means in a mineral substrate (substrate) to accelerate the hardening of the cement, the mortar system comprising a settable alumina cement component A and an initiator component B for starting the hardening process, component A further comprising at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid, boric acid and phosphonic acid, and component B comprising an activator.

[0013] In another aspect, the invention relates to a method for the chemical fastening of fastening means, preferably metal elements, in mineral substrates such as structures made of brickwork, concrete, permeable concrete or natural stone.

[0014] The following terms and definitions are used in the context of the present invention.

[0015] As used in the context of the present invention, the singular forms "a" and "an" also include the respective plural forms unless the context clearly dictates otherwise. Thus, the terms "a" or "an" are intended to mean "one or more" or "at least one," unless otherwise specified.

[0016] The term "aluminous cement" in the context of this invention refers to calcium aluminate cement, which consists primarily of hydrated active calcium aluminate. Another name for this is "high alumina cement" or "Ciment fondu" in French. The main active ingredient in calcium aluminate cement is monocalcium aluminate (CaAl2O4, CaO·Al2O3, or CA in cement chemistry).

[0017] The term "activator" in the context of the present invention refers to a compound or composition that modifies the chemical environment to initiate a specific chemical reaction. In the present invention, the activator modifies the pH value of the mortar suspension, thereby unblocking the hydraulic binder in the final mixture.

[0018] The term "retarder" in the context of the present invention refers to a compound or composition that modifies the chemical environment so as to slow down certain chemical reactions. In the present invention, retarders modify the hydration capacity of the calcium aluminate cement of the mortar suspension, thereby slowing down the action of the hydraulic binder in the final mixture.

[0019] The term "initial setting time" in the context of the present invention refers to the time at which the mixture of components A and B begins to harden after mixing. During the period after mixing, the mixture remains in the form of a more or less fluid aqueous suspension or a paste of solid product.

[0020] Surprisingly, the inventors have found that the addition of at least one alkali metal salt and / or alkaline earth metal salt to inorganic mortar systems for chemical fastening of fastening means in mineral substrates, comprising a settable alumina cement component, preferably one based on calcium aluminate cement, significantly accelerates cement hardening and increases load values compared to systems that do not contain at least one alkali metal salt and / or alkaline earth metal salt in the settable alumina cement component, particularly when at least one alkali metal salt and / or alkaline earth metal salt is present in the settable alumina cement component. It has also been found that the addition of at least one alkali metal salt and / or alkaline earth metal salt does not adversely affect the handling, characteristics, and mechanical performance of the chemical fastening system (adhesive system), particularly when applied to diamond drilled holes, wet drilled holes, and over long periods of time.

[0021] The present invention therefore relates to the use of at least one alkali metal salt and / or alkaline earth metal salt in an inorganic mortar system for the chemical fastening of fastening means in a mineral matrix to accelerate the hardening of the cement, comprising a settable alumina cement component A and an initiator component B for starting the hardening process, component A further comprising at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid, boric acid and phosphonic acid, and component B comprising an activator. In particular, the at least one alkali metal salt and / or alkaline earth metal salt is advantageously present in component A.

[0022] Component A used in the present invention is based on aluminous cement (CAC) or calcium sulfoaluminate cement (CSA). The aluminous cement component that can be used in the present invention is preferably an aluminous cement component based on aqueous calcium aluminate cement (CAC). The aluminous cement used in the present invention is characterized by rapid setting and hardening, rapid drying, and excellent resistance to corrosion and shrinkage. Such calcium aluminate cement suitable for use in the present invention is, for example, Ternal® White (Kerneos, France).

[0023] Component A used in 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, and most preferably at least about 70% by weight, and from about 40% to about 95% by weight, preferably from about 50% to about 85% by weight, more preferably from about 60% to about 80% by weight, and most preferably from about 70% to about 75% by weight of alumina cement.

[0024] According to an alternative embodiment of the present invention, the component A used comprises at least about 20 wt%, preferably at least about 30 wt%, more preferably at least about 40 wt%, and most preferably at least about 50 wt%, or about 20 wt% to about 80 wt%, preferably about 30 wt% to about 70 wt%, more preferably about 35 wt% to about 60 wt%, and most preferably about 40 wt% to about 55 wt% aluminous cement, based on the total weight of component A, and at least about 5 wt%, preferably at least about 10 wt%, more preferably at least about 15 wt%, most preferably at least about 20 wt%, about 1 wt% to about 50 wt%, preferably about 5 wt% to about 40 wt%, more preferably about 10 wt% to about 30 wt%, and most preferably about 15 wt% to about 25 wt% calcium sulfate, preferably calcium sulfate hemihydrate, based on the total weight of component A. In a preferred alternative embodiment of the two-component mortar system of the present invention, the CaSO4 / CAC ratio in component A should be 35:65 or less.

[0025] The blocking agent contained in Component A used in 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, and most preferably phosphoric acid, particularly an 85% aqueous solution of phosphoric acid. Component A contains at least about 0.1 wt. %, preferably at least about 0.3 wt. %, more preferably at least about 0.4 wt. %, most preferably at least about 0.5 wt. %, about 0.1 wt. % to about 20 wt. %, preferably about 0.1 wt. % to about 15 wt. %, more preferably about 0.1 wt. % to about 10 wt. %, most preferably about 0.3 wt. % to about 5 wt. % of the blocking agent, based on the total weight of Component A. In a preferred embodiment, Component A contains about 0.3 wt. % to about 10 wt. % of an 85% aqueous solution of phosphoric acid, based on the total weight of Component A. Preferably, the amount of alumina cement and / or calcium sulfoaluminate cement by weight relative to the total weight of the hydraulic binder is higher than any of the following values: 50%, 60%, 70%, 80%, 90%, 95%, 99% or 100%.

[0026] The at least one alkali metal salt and / or alkaline earth metal salt (also called accelerator component) in an inorganic mortar system for chemical fastening of fastening means in a mineral matrix for accelerating the hardening of cement is composed of at least one alkali metal salt and / or alkaline earth metal salt selected from the group consisting of hydroxides, chlorides, sulfates, phosphates, monohydrogen phosphates, dihydrogen phosphates, nitrates, nitrites, carbonates, and mixtures thereof, preferably the accelerator component is an alkali metal salt or alkaline earth metal salt, more preferably a water-soluble alkali metal salt or alkaline earth metal salt, more preferably , calcium metal salts such as calcium hydroxide, calcium sulfate, calcium carbonate, calcium nitrate, calcium nitrite, calcium chloride, calcium formate, or calcium phosphate; sodium metal salts such as sodium hydroxide, sodium sulfate, sodium carbonate, sodium nitrate, sodium nitrite, sodium chloride, sodium formate, or sodium phosphate; or lithium metal salts such as lithium hydroxide, lithium sulfate, lithium sulfate monohydrate, lithium carbonate, lithium nitrate, lithium chloride, lithium formate, or lithium phosphate, most preferably lithium sulfate or lithium sulfate monohydrate.

[0027] The at least one alkali metal salt and / or alkaline earth metal salt used according to the invention is preferably contained in the settable alumina cement component A of the inorganic mortar system. In a preferred embodiment of the invention, the at least one alkali metal salt and / or alkaline earth metal salt is contained in the settable alumina cement component based on aqueous-phase calcium aluminate cement of the inorganic mortar system.

[0028] Component A comprises at least about 0.005 wt. %, preferably at least about 0.01 wt. %, more preferably at least about 0.05 wt. %, and most preferably at least about 0.1 wt. %, from about 0.005 wt. % to about 10 wt. %, preferably from about 0.01 wt. % to about 5 wt. %, more preferably from about 0.1 wt. % to about 1 wt. %, and most preferably from about 0.1 wt. % to about 0.5 wt. % of the accelerator described above, based on the total weight of Component A.

[0029] Component A may further comprise a plasticizer. The plasticizer contained in component A may be selected from the group consisting of low molecular weight (LMW) polyacrylic acid polymers, flow regulators from the polyphosphonate and polycarbonate polyox families, and ethacrylic superplasticizers from the polycarboxylate ether group, and mixtures thereof, such as 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 at least about 0.2 wt %, preferably at least about 0.3 wt %, more preferably at least about 0.4 wt %, and most preferably at least about 0.5 wt %, about 0.2 wt % to about 20 wt %, preferably about 0.3 wt % to about 15 wt %, more preferably about 0.4 wt % to about 10 wt %, and most preferably about 0.5 wt % to about 5 wt % of the above-mentioned plasticizer, based on the total weight of Component A.

[0030] In an advantageous embodiment of the invention, the component A used further comprises the following features, alone or in combination:

[0031] Component A may further comprise a thickener. Thickeners that can be used in the present invention may be selected from the group consisting of organic products such as xanthan gum, welan gum, or DIUTAN® gum (CP Kelko, USA), mineral products such as starch-derived ethers, guar-derived ethers, polyacrylamides, carrageenans, agar, and clays, and mixtures thereof. Suitable thickeners are commercially available products. Component A contains at least about 0.01% by weight, preferably at least about 0.1% by weight, more preferably at least about 0.2% by weight, and most preferably at least about 0.3% by weight, from about 0.01% to about 10% by weight, preferably from about 0.1% to about 5% by weight, more preferably from about 0.2% to about 1% by weight, and most preferably from about 0.3% to about 0.7% by weight of the above-mentioned thickener, based on the total weight of Component A.

[0032] Component A may further comprise an antibacterial agent or biocide. The antibacterial 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 antibacterial agents or biocides are commercially available products. Illustratively mentioned are Ecocide K35R (Progiven, France) and Nuosept OB 03 (Ashland, The Netherlands). Component A comprises at least about 0.001 wt. %, preferably at least about 0.005 wt. %, more preferably at least about 0.01 wt. %, and most preferably at least about 0.015 wt. %, from about 0.001 wt. % to about 1.5 wt. %, preferably from about 0.005 wt. % to about 0.1 wt. %, more preferably from about 0.01 wt. % to about 0.075 wt. %, and most preferably from about 0.015 wt. % to about 0.03 wt. % of the above-described antimicrobial or biocide, based on the total weight of Component A. In a preferred embodiment, Component A comprises from about 0.015 wt. % to about 0.03 wt. % Nuosept OB 03, based on the total weight of Component A.

[0033] In an alternative embodiment, component A comprises at least one filler, in particular an organic or mineral filler. Fillers that can be used in the present invention can be selected from the group consisting of quartz powder, preferably quartz powder with an average particle size (d50%) of about 16 μm, silica sand, clay, fly ash, fumed silica, carbonate compounds, alumina, pigments, titanium dioxide, light fillers, and mixtures thereof. Suitable mineral fillers are commercially available products. Exemplary mention is made of quartz powder Millisil W12 or W6 (Quarzwerke GmbH, Germany). Component A comprises at least about 1 wt. %, preferably at least about 2 wt. %, more preferably at least about 5 wt. %, and most preferably at least about 8 wt. % of the at least one filler described above, based on the total weight of component A.

[0034] The water content of Component A as used herein is at least about 1% by weight, preferably at least about 5% by weight, more preferably at least about 10% by weight, and 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, based on the total weight of Component A.

[0035] The presence of accelerators, plasticizers, thickeners, and antimicrobial or biocides does not change the overall inorganic nature of cementitious component A.

[0036] Component A, which comprises an alumina cement or calcium sulfoaluminate cement, is present in the aqueous phase, preferably in the form of a slurry or paste.

[0037] The component B used in the present invention comprises an activator, at least one retarder, and optionally at least one mineral filler and water. To ensure sufficient processing time, at least one retarder is used in a separate concentration in addition to the initiator component to prevent premature hardening of the mortar composition.

[0038] The activator present in component B comprises at least one alkali metal salt 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.

[0039] In particular, the activator component is composed of at least one alkali metal salt 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 activator component is an alkali metal salt or alkaline earth metal salt, more preferably a calcium metal salt such as calcium hydroxide, calcium sulfate, calcium carbonate, calcium formate, calcium nitrate or calcium phosphate, a sodium metal salt such as sodium hydroxide, sodium sulfate, sodium carbonate, sodium nitrate or sodium phosphate, a lithium metal salt such as lithium hydroxide, lithium sulfate, lithium carbonate, lithium nitrate or lithium phosphate, or a potassium metal salt such as potassium hydroxide, potassium sulfate, potassium carbonate, potassium formate, potassium nitrate or potassium phosphate, and most preferably sodium hydroxide.

[0040] Component B contains at least about 0.01 wt%, preferably at least about 0.02 wt%, more preferably at least about 0.05 wt%, and most preferably at least about 1 wt%, of the activator described above, based on the total weight of Component B. From about 0.01 wt% to about 40 wt%, preferably from about 0.02 wt% to about 35 wt%, more preferably from about 0.05 wt% to about 30 wt%, and most preferably from about 1 wt% to about 25 wt%. In a particularly preferred embodiment, the activator is sodium hydroxide. The water content of Component B is at least about 1 wt%, preferably at least about 5 wt%, more preferably at least about 10 wt%, and most preferably at least about 20 wt%, from about 1 wt% to about 60 wt%, preferably from about 5 wt% to about 50 wt%, more preferably from about 10 wt% to about 40 wt%, and most preferably from about 15 wt% to about 30 wt%, based on the total weight of Component B. In a particularly preferred embodiment, the sodium hydroxide content in Component B is at least about 0.1% by weight, preferably at least about 1% by weight, more preferably at least about 2% by weight, and most preferably at least about 3% by weight, and is about 0.1% to about 15% by weight, preferably about 1% to about 10% by weight, more preferably about 2% to about 8% by weight, and most preferably about 3% to about 6% by weight, based on the total weight of Component B.

[0041] The at least one retarder contained in Component B used in the present invention is selected from the group consisting of citric acid, tartaric acid, lactic acid, salicylic acid, gluconic acid, and mixtures thereof, and is preferably a mixture of citric acid and tartaric acid. Component B contains at least about 0.1 wt. %, preferably at least about 0.2 wt. %, more preferably at least about 0.5 wt. %, and most preferably at least about 1.0 wt. %, from about 0.1 wt. % to about 25 wt. %, preferably from about 0.2 wt. % to about 15 wt. %, more preferably from about 0.5 wt. % to about 15 wt. %, and most preferably from about 1.0 wt. % to about 10 wt. % of the retarder, based on the total weight of Component B.

[0042] In a particularly preferred embodiment of component B used according to the invention, the citric acid / tartaric acid ratio is 1.6 / 1.

[0043] The at least one mineral filler contained in component B used in the present invention may be selected from the group consisting of limestone filler, sand, corundum, dolomite, alkali-resistant glass, alumina, crushed stone, gravel, pebbles, and mixtures thereof, and is preferably a limestone filler such as various calcium carbonates. The at least one mineral filler is preferably selected from the group consisting of limestone filler or quartz fillers such as quartz powder Millisil W12 or W6 (Quarzwerke GmbH, Germany) and silica sand. The at least one mineral filler of component B is most preferably calcium carbonate or a mixture of calcium carbonates. Component B comprises at least about 30% by weight, preferably at least about 40% by weight, more preferably at least about 50% by weight, even more preferably at least about 60% by weight, and most preferably at least about 70% by weight, from about 30% to about 95% by weight, preferably from about 35% to about 90% by weight, more preferably from about 40% to about 85% by weight, even more preferably from about 45% to about 80% by weight, and most preferably from about 50% to about 75% by weight of at least one mineral filler, based on the total weight of Component B.

[0044] In a particularly preferred embodiment, the at least one mineral filler included in component B is a mixture of three different calcium carbonates, i.e., calcium carbonate fines, such as different Omyacarb® types (Omya International AG, Germany). Most preferably, the first calcium carbonate has an average particle size (d50%) of about 3.2 μm and a residue on a 45 μm sieve of 0.05% (determined according to ISO 787 / 7). The second calcium carbonate has an average particle size (d50%) of about 7.3 μm and a residue on a 140 μm sieve of 0.5% (determined according to ISO 787 / 7). The third calcium carbonate has an average particle size (d50%) of about 83 μm and a residue on a 315 μm sieve of 1.0% (determined according to ISO 787 / 7).

[0045] In a particularly preferred alternative embodiment, the at least one mineral filler included in component B is a mixture of three different quartz fillers. Most preferably, the first quartz filler is silica sand with an average particle size (d50%) of about 240 μm. The second quartz filler is quartz powder with an average particle size (d50%) of about 40 μm. The third quartz filler is quartz powder with an average particle size (d50%) of about 15 μm.

[0046] In an advantageous embodiment, component B further comprises the following characteristics, alone or in combination:

[0047] Component B may additionally contain a thickener. The thickener used in the present invention may be selected from the group consisting of bentonite, silicon dioxide, quartz, acrylate-based thickeners such as alkali-soluble or alkali-swellable emulsions, fumed silica, clay, and titanate chelating agents, or combinations thereof. Exemplary thickeners include polyvinyl alcohol (PVA), hydrophobically modified alkali-soluble emulsions (HASE), hydrophobically modified ethylene oxide urethane polymers known in the art as HEUR, and cellulose-based 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 ethyl cellulose, 2-hydroxypropyl cellulose, attapulgite clay, and mixtures thereof. Suitable thickeners are commercially available products such as Optigel WX (BYK-Chemie GmbH, Germany), Rheolate 1 (Elementis GmbH, Germany), and Acrysol ASE-60 (The Dow Chemical Company). Component B contains at least about 0.01 wt. %, preferably at least about 0.05 wt. %, more preferably at least about 0.1 wt. %, and most preferably at least about 0.3 wt. %, from about 0.01 wt. % to about 15 wt. %, preferably from about 0.05 wt. % to about 10 wt. %, more preferably from about 0.1 wt. % to about 5 wt. %, and most preferably from about 0.3 wt. % to about 1 wt. % of the above-described thickener, based on the total weight of Component B.

[0048] The presence of retarders and thickeners does not change the overall inorganic nature of cementitious Component B. Component B may also contain plasticizers or dispersants, which are known to those skilled in the art.

[0049] Component B, which contains the activator and retarder, is present in the aqueous phase, preferably in the form of a slurry or paste.

[0050] It is preferred that the pH value of component B is above 10, more preferably above 11, most preferably above 12, especially in the range 10-14, preferably in the range 11-13.

[0051] It is particularly preferred that the ratio of water in the two components, component A and component B, is selected so that the ratio of water to alumina cement (W / CAC) or water to calcium sulfoaluminate cement (W / CAS) in the product obtained by mixing components A and B is less than 1.5, preferably between 0.2 and 1.2, most preferably between 0.3 and 0.8. In a preferred embodiment, the ratio of water to calcium aluminate cement with calcium sulfate (W / (CAC+CaSO4)) in the product obtained by mixing components A and B is less than 0.35.

[0052] Furthermore, it is particularly preferred that the proportion of lithium in component A is selected so that in the product obtained by mixing components A and B, the ratio of lithium to alumina cement (Li / CAC) and the ratio of lithium to calcium sulfoaluminate cement (Li / CAS) is less than 0.05, preferably between 0.00005 and 0.05, most preferably between 0.0001 and 0.001. In a particularly preferred embodiment, the proportion of lithium sulfate monohydrate in component A is selected so that the ratio of calcium aluminate cement with calcium sulfate to lithium sulfate monohydrate ((CAC + CaSO4) / Li2SO4 xH2O) in the product obtained by mixing components A and B is in the range of 50:1 to 2,000:1, more preferably in the range of 300:1 to 1,500:1, and even more preferably in the range of 500:1 to 600:1.

[0053] Furthermore, it is particularly preferred that the proportion of retarder in component B is selected so that in the product obtained by mixing components A and B, the ratio of citric acid / tartaric acid to alumina cement and the ratio of citric acid / tartaric acid to calcium sulfoaluminate cement are less than 0.1, preferably between 0.005 and 0.08, most preferably between 0.007 and 0.3.

[0054] In the most preferred embodiment, component A comprises or consists of the following components: 70-85% by weight of alumina cement, 0.5 to 1.5% by weight of phosphoric acid, 0.05% to 2.0% by weight of lithium sulfate or lithium sulfate monohydrate; 0.5 to 1.5 wt. % of a plasticizer; 0.001 to 0.05 wt. % of an antimicrobial or biocide; Optionally, 5 to 20 wt. % of a mineral filler, and 15-25% water by weight.

[0055] In the most preferred embodiment, component B comprises or consists of the following components: 0.1% to 5% by weight of sodium hydroxide, 0.05% to 5% by weight of citric acid, 0.05% to 4% by weight of tartaric acid, 35% to 45% by weight of a first mineral filler; 15% to 25% by weight of a second mineral filler; 10% to 20% by weight of a third mineral filler; 0.01% to 0.5% by weight of a thickening agent; optionally, additional fillers, and 15% to 25% water by weight.

[0056] Component A used in the present invention can be prepared as follows: a phosphorus-containing blocking agent is mixed with water so that the pH value of the resulting mixture is about 2; a plasticizer and an antibacterial / fungicide are added, and the mixture is homogenized; alumina cement, (optionally calcium sulfate), and optionally a mineral filler are premixed and gradually added to the mixture with increasing stirring speed so that the pH value of the resulting mixture is about 7; and finally, an accelerator and thickener are added, and the mixture is mixed until completely homogenized.

[0057] Component B used in the present invention may be prepared as follows: the activator is dissolved in deionized water, followed by the addition of the retarder and thickener and optionally the mineral filler while stirring until the mixture is homogenized, finally obtaining a smooth liquid paste-like slurry with a pH greater than 12.

[0058] Components A and B are present in the aqueous phase, preferably in the form of a slurry or paste. In particular, components A and B have a pasty to fluid appearance according to their respective compositions. In a preferred embodiment, components A and B are in the form of a paste, thereby preventing sagging when mixing the two components.

[0059] The weight ratio between component A and component B (A / B) is preferentially comprised between 7 / 1 and 1 / 3, preferably 3 / 1. Preferably, the composition of the mixture comprises 75% by weight of component A and 25% by weight of component B. In an alternative embodiment, the composition of the mixture comprises 25% by weight of component A and 75% by weight of component B.

[0060] The inorganic mortar system, preferably the two-component inorganic mortar system, is of a mineral nature that is not affected by the presence of additional thickeners or other agents.

[0061] After mixing of the two components A and B, it is preferred that the inorganic 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, in particular in the range of about 5 to 25 minutes, preferably in the range of about 10 to 20 minutes.

[0062] In multi-component inorganic mortar systems, especially two-component inorganic mortar systems, the volume ratio of cementitious component A to initiator component B is between 1:1 and 7:1, preferably 3:1. In an alternative embodiment, the volume ratio of cementitious component A to initiator component B is between 1:3 and 1:2.

[0063] After being prepared separately, components A and B are introduced into separate containers, from which they are discharged by a mechanical device and guided through a mixing device. The inorganic mortar system is preferably a ready-to-use system, whereby components A and B are arranged separately from each other in a multi-chamber device, such as a multi-chamber cartridge and / or a multi-chamber cylinder, or in a two-component capsule, preferably in a two-chamber cartridge or a two-component capsule. The multi-chamber system preferably comprises two or more foil bags for separating the hardenable component A and the initiator component B. The contents of the chambers or bags, which are mixed together by the mixing device, preferably via a static mixer, can be injected into the drilled hole. Assembly in a set of multiple chamber cartridges or pails or buckets is also possible.

[0064] The setting alumina cement composition emerging from the static mixer is inserted directly into the drilled holes required for fastening the fastening means and the installed reinforcement, and is first introduced into the mineral matrix during the chemical fastening of the fastening means and the installed reinforcement, during which the construction elements to be fastened, such as anchor rods, are inserted and adjusted, during which the mortar composition hardens and hardens. In particular, inorganic mortar systems should be considered for the chemical fastening and installed reinforcement for fastening metal elements.

[0065] The role of the mineral fillers, especially in component B, is to tailor the final performance in terms of mechanical strength and performance, as well as long-term durability. By optimizing the fillers, it is possible to optimize the water / solids ratio, which allows for efficient and rapid hydration of the aluminous cement and low porosity in the final cement matrix.

[0066] Inorganic mortar systems comprising at least one alkali metal salt and / or alkaline earth metal salt can be used for the chemical fastening of fastening means, preferably metal elements such as anchor rods, especially threaded rods, bolts, steel reinforcements, etc., into mineral substrates such as brickwork, concrete, permeable concrete, or structures made of natural stone. In particular, inorganic mortar systems can be used for the chemical fastening of fastening means, such as metal elements in drilled holes. It has been found that the use of at least one alkali metal salt and / or alkaline earth metal salt in such inorganic mortar systems significantly accelerates the hardening of the cement.

[0067] The use of at least one alkali metal salt and / or alkaline earth metal salt in the inorganic mortar system according to the invention is therefore in particular to accelerate the hardening of the cement.

[0068] The at least one alkali metal salt and / or alkaline earth metal salt contained in the inorganic mortar, in particular when present in component A, is particularly applicable to methods for the chemical fastening of fastening means, preferably metal elements, in mineral substrates such as brickwork, concrete, permeable concrete or structures made of natural stone.

[0069] Furthermore, inorganic mortar systems comprising at least one alkali metal salt and / or alkaline earth metal salt can be used, in particular, for the installation of fibers, scrims, fabrics, or composites, in particular high-modulus fibers, preferably carbon fibers, for the reinforcement of walls or ceilings or floors, in building structures, or even for the installation of components, such as plates or blocks of stone, glass, or plastic, to buildings or structural elements. In particular, however, inorganic mortar systems are used for the fastening of fastening means, preferably metal elements such as anchor rods, in particular threaded rods, bolts, steel reinforcements, etc., into recesses, such as drilled holes, in mineral substrates, such as masonry, concrete, permeable concrete, or structures made of natural stone, whereby the components of the two-component inorganic mortar system are premixed, for example, by means of a static mixer, by breaking cartridges or plastic bags, or by mixing the components in a set of multi-chamber pails or buckets. [Example]

[0070] The following examples illustrate the present invention without, however, limiting it thereto. 1. Preparation of Components A and B The cementitious component A and initiator component B of Comparative Examples 1 and 2 and Inventive Examples 1 and 2 are prepared by first mixing the components identified in Tables 1 and 2, respectively. The percentages given are expressed in weight percent.

[0071] 1.1 Component A 16.53 or 16.38 grams of deionized water, 0.75 grams of 85% phosphoric acid (blocking agent), 1.2 grams of Ethacryl G® (superplasticizer), and 0.02 grams of Nuosept® (bactericide) were homogenized at room temperature, and while stirring with a dissolver, calcium aluminate cement (81.00 grams, pure Ternal White®) was then added in small portions to finally obtain a smooth, liquid, paste-like slurry of blocked cement in water with a pH of less than 7. After adding the calcium aluminate cement, in the present example, 0.15 grams of lithium sulfate was added, followed by 0.5 grams of xanthan gum (thickener), and the slurry was homogenized. Alternatively, the accelerator can be added to the liquid phase in advance.

[0072] [Table 1]

[0073] 1.2 Component B In each amount of deionized water, 4.0 grams of NaOH pellets (activator), 0.65 grams of Ecodis® P50 (superplasticizer), 0.4 grams of Optigel® WX (thickener), optionally 0.43 grams of Li2SO4 (accelerator), 1.93 grams of citric acid, and 1.20 grams of tartaric acid were dissolved. While stirring in a dissolver, the filler mixture was added in the following portions: 33.00 grams of corundum ZWSK 150 or 34.00 grams of calcite Omyacarb 130 AL, 18.00 grams of ZWSK 360 or 15.39 grams of Omyacarb 15 AL, 8.89 grams of ZWSK 800 or 9.0 grams of Omyacarb 2 AL, and 14.5 grams or 13.0 grams of calcite Calofort U, respectively, to finally obtain a smooth liquid paste-like slurry of filler in water with a pH greater than 12.

[0074] [Table 2]

[0075] 3. Mechanical Performance Determination After preparation of the single components, the corresponding A and B components were filled into plastic hard cartridges at a mixing ratio of A:B = 3:1. The hard cartridges were placed in a dispenser and injected into drilled holes in concrete plates. The drilled holes measured 72 mm deep and 14 mm in diameter. Before injecting the mortar, the drilled holes were cleaned by compressed air flushing and brushing. A steel grade 12.9 threaded rod was then inserted into the drilled holes. The pull-out strength was measured after different curing times to determine the improved curing behavior of the inventive examples. Each series consisted of four pull-out values per curing time. The pull-out test results are shown in Table 3.

[0076] [Table 3]

[0077] These results show that multi-component calcium aluminate cement slurries containing the accelerator component in the A component have significantly improved load values after 18 and 24 hours of hardening compared to systems in which the accelerator compound is present in the B component. This indicates that the addition of at least one alkali metal salt and / or alkaline earth metal salt accelerator (particularly as shown for the Li accelerator) to the A component, even when used in very low concentrations, leads to more uniform distribution within the mortar and improved hardening, and therefore hardening behavior, in the examples of the present invention, especially independent of the filler used in the initiator component.

Claims

1. 1. Use of at least one alkali metal salt and / or alkaline earth metal salt in an inorganic mortar system for the chemical fastening of fastening means in a mineral substrate (material to be fastened) to accelerate the hardening of the cement, the system comprising a settable alumina cement component A and an initiator component B for starting the hardening process, the component A further comprising at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid, boric acid and phosphonic acid, and the component B comprising an activator.

2. 2. The use according to claim 1, wherein the alumina cement component A is an alumina cement component based on aqueous phase calcium aluminate cement.

3. 3. The use according to claim 1 or 2, wherein component B further comprises at least one retarder, at least one mineral filler and water.

4. 4. Use according to any one of claims 1 to 3, wherein the at least one alkali metal salt and / or alkaline earth metal salt for accelerating the hardening of the cement is comprised in the settable alumina cement component A of the inorganic mortar system.

5. 5. Use according to any one of claims 1 to 4, wherein the at least one alkali metal salt and / or alkaline earth metal salt for accelerating the hardening of the cement consists of at least one alkali metal salt 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.

6. 6. Use according to any one of claims 1 to 5, wherein the at least one alkali metal salt and / or alkaline earth metal salt for accelerating the setting of the cement is lithium hydroxide, lithium sulphate, lithium sulphate monohydrate, lithium carbonate, lithium nitrate, lithium chloride, lithium formate or lithium phosphate, most preferably lithium sulphate or lithium sulphate monohydrate.

7. 7. The use according to any one of claims 1 to 6, wherein the activator comprises at least one alkali metal salt and / or alkaline earth metal salt, the at least one retarder is selected from the group consisting of citric acid, tartaric acid, lactic acid, salicylic acid, gluconic acid, and mixtures thereof, and the at least one mineral filler is selected from the group consisting of limestone filler, sand, corundum, dolomite, alkali-resistant glass, alumina, crushed stone, gravel, pebbles, and mixtures thereof.

8. The use according to any one of claims 1 to 7, wherein the activating agent comprises only sodium hydroxide.

9. 9. The use according to any one of claims 1 to 8, wherein the at least one alkali metal salt and / or alkaline earth metal salt for accelerating the hardening of the cement is present in the product obtained by mixing components A and B in the range of about 0.05% to 10.0% by weight.

10. The use according to any one of claims 1 to 9, wherein the fastening means is an anchor rod, a threaded anchor rod, a bolt, or a steel reinforcement.

11. Use according to any one of claims 1 to 10, wherein the mineral substrate is a structure made of brickwork, concrete, pervious concrete or natural stone.

12. Use according to any one of claims 1 to 11 in a method for the chemical fastening of fastening means, preferably metal elements, in mineral substrates such as brickwork, concrete, permeable concrete or structures made of natural stone.

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