Use of at least one alkali metal salt and / or alkaline earth metal salt in an alumina cement-based inorganic mortar system to accelerate the hardening of cement in chemical fastenings - Patents.com

Abstract

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 chemical fastening of fastening means in mineral substrates, 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, component B comprising an activator.Furthermore, the present invention relates to the use of at least one alkali metal salt and / or alkaline earth metal salt in an inorganic mortar for accelerating the hardening of cement and increasing the load value, as well as to a method for chemical fastening of fastening means, preferably metal elements, in mineral substrates such as brickwork, concrete, permeable concrete or structures made of natural stone.

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 chemical (adhesive-based) fastening of fastening means in mineral substrates, comprising a settable alumina cement component A and an initiator component B for initiating 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 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 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 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] There are many mortar systems that provide good chemical (adhesive system) 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 the people 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 thermally at high temperatures such as fire, thereby reducing the mechanical performance with respect to the chemical fastening of fastening means.

[0003] To overcome these shortcomings, mainly mineral systems based 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 shows a high level of mechanical performance over time. It 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 most practical applications of the resulting compositions.In many cases, such prior art compositions also show a tendency to crack in a relatively short time or do not exhibit the required mechanical performance under certain conditions, such as, in particular, under the effect of high temperatures, in diamond drill holes or in wet drill holes, as well as over a long period of time.Moreover, known systems tend to show significant shrinkage when applied to drill holes, thereby resulting in insufficient fastening of fastening means.

[0005] Furthermore, there is a need to significantly accelerate the hardening of cement, since this can speed up construction at the building site, thereby saving valuable labor hours. In addition, there is a need to reduce warning labeling by reducing harmful substances, such as carcinogenic, toxic, mutagenic or environmentally harmful substances, in the fastening system, such as peroxides, reactive diluents and resins, in order to improve handling safety during production and for workers, and during transportation, and to reduce the 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, which 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 long periods 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 been a long felt 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 structures made of brickwork, concrete, permeable concrete or 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 an inorganic mortar system to accelerate the hardening of the cement in chemical fastenings, to provide sustainability and to reduce 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-based) fastening of a fastening means in a mineral substrate (substrate) 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.

[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 specifically stated otherwise.

[0016] The term "aluminous cement" in the context of the present invention refers to calcium aluminate cement, which consists mainly of hydrated active calcium aluminate. Another name is "high aluminous cement" or in French "Ciment fondu". The main active ingredient of calcium aluminate cement is monocalcium aluminate (CaAl 2 O 4 , CaO·Al 2 O 3 , or CA in cement chemical notation.

[0017] The term "activator" in the context of the present invention refers to a compound or composition that modifies the chemical environment so as 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 mix.

[0018] The term "retarder" in the context of the present invention refers to a compound or composition that modifies the chemical environment to retard certain chemical reactions. In the present invention, retarders modify the hydration capacity of the calcium aluminate cement of the mortar suspension, thereby retarding 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 a mixture of components A and B begins to set 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 a solid product.

[0020] Surprisingly, the inventors have found that the addition of at least one alkali metal salt and / or alkaline earth metal salt in inorganic mortar systems for chemical fastening of fastening means in mineral substrates, including a hardenable alumina cement component, preferably one based on calcium aluminate cement, significantly accelerates the hardening of the cement and increases the load values, compared to systems that do not include at least one alkali metal salt and / or alkaline earth metal salt in the hardenable alumina cement component, especially when at least one alkali metal salt and / or alkaline earth metal salt is present in the hardenable 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), especially when applied to diamond drill holes, wet drill 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 chemical fastening of fastening means in a mineral substrate 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] The 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 phase calcium aluminate cement (CAC). The aluminous cement used in the present invention is characterized by rapid set 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 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, about 40% to about 95% by weight, preferably about 50% to about 85% by weight, more preferably about 60% to about 80% by weight, and most preferably about 70% to about 75% by weight of alumina cement, based on the total weight of Component A.

[0024] According to an alternative embodiment of the present invention, the component A used comprises 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 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, based on the total weight of component A, and at least about 5% by weight, preferably at least about 10% by weight, more preferably at least about 15% 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, most preferably about 15% to about 25% by weight of 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 CaSO 4 of component A is4 The ratio of / CAC 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, most preferably phosphoric acid, particularly an 85% aqueous solution of phosphoric acid. Component A contains 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, most preferably about 0.3% to about 5% by weight of the above-mentioned blocking agent based on the total weight of component A. In a preferred embodiment, component A contains about 0.3% to about 10% by weight 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 in an inorganic mortar system for chemical fastening of fastening means in a mineral matrix for accelerating the hardening of cement (also called accelerator 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, 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 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, and 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 comprised 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 comprised in the settable alumina cement component based on an aqueous phase calcium aluminate cement of the inorganic mortar system.

[0028] Component A contains at least about 0.005% by weight, preferably at least about 0.01% by weight, more preferably at least about 0.05% by weight, and most preferably at least about 0.1% by weight, from about 0.005% by weight to about 10% by weight, preferably from about 0.01% by weight to about 5% by weight, more preferably from about 0.1% by weight to about 1% by weight, and most preferably from about 0.1% by weight to about 0.5% by weight 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 agents from the families of polyphosphonate polyox and polycarbonate polyox, 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% by weight, preferably at least about 0.3% by weight, more preferably at least about 0.4% by weight, and 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 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 thickening agent. The thickening agent that may 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 thickening agents are commercially available products. Component A comprises 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 above-mentioned thickening agent, 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 may 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. Exemplary mention may be made of Ecocide K35R (Progiven, France) and Nuosept OB 03 (Ashland, The Netherlands). Component A comprises at least about 0.001% by weight, preferably at least about 0.005% by weight, more preferably at least about 0.01% by weight, and most preferably at least about 0.015% by weight, from about 0.001% to about 1.5% by weight, preferably from about 0.005% to about 0.1% by weight, more preferably from about 0.01% to about 0.075% by weight, and most preferably from about 0.015% to about 0.03% by weight of the above-mentioned antimicrobial or biocide, based on the total weight of Component A. In a preferred embodiment, Component A comprises from about 0.015% to about 0.03% by weight of 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 may be used in the present invention may 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. Exemplarily mentioned are quartz powder Millisil W12 or W6 (Quarzwerke GmbH, Germany). Component A comprises at least about 1% by weight, preferably at least about 2% by weight, more preferably at least about 5% by weight, most preferably at least about 8% by weight of at least one filler as mentioned above, based on the total weight of component A.

[0034] The water content contained in Component A as used herein 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, and most preferably at least about 20% by weight, from about 1% by weight to about 50% by weight, preferably from about 5% by weight to about 40% by weight, more preferably from about 10% by weight to about 30% by weight, and most preferably from about 15% by weight to about 25% by weight.

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

[0036] Component A, which comprises an alumina cement or a calcium sulphoaluminate 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 an 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, or 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, most preferably sodium hydroxide.

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

[0041] 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% by weight, preferably at least about 0.2% by weight, more preferably at least about 0.5% by weight, most preferably at least about 1.0% by weight, about 0.1% to about 25% by weight, preferably about 0.2% to about 15% by weight, more preferably about 0.5% to about 15% by weight, most preferably about 1.0% to about 10% by weight of the retarder described above, 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, preferably 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 filler, 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 contained 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 of 0.05% on a 45 μm sieve (determined according to ISO 787 / 7). The second calcium carbonate has an average particle size (d50%) of about 7.3 μm and a residue of 0.5% on a 140 μm sieve (determined according to ISO 787 / 7). The third calcium carbonate has an average particle size (d50%) of about 83 μm and a residue of 1.0% on a 315 μm sieve (determined according to ISO 787 / 7).

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

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

[0047] Component B may additionally comprise 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, clays, and titanate chelating agents, or combinations thereof. Exemplary mention may be made of 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 hydroxymethylcellulose (HMC), hydroxyethylcellulose (HEC), hydrophobically modified hydroxyethylcellulose (HMHEC), sodium carboxymethylcellulose (SCMC), sodium carboxymethyl 2-hydroxyethylcellulose, 2-hydroxypropylmethylcellulose, 2-hydroxyethylmethylcellulose, 2-hydroxybutylmethylcellulose, 2-hydroxyethylethylcellulose, 2-hydroxypropylcellulose, attapulgite clay, and mixtures thereof. Suitable thickeners are commercial 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% by weight, preferably at least about 0.05% by weight, more preferably at least about 0.1% by weight, and most preferably at least about 0.3% by weight, from about 0.01% to about 15% by weight, preferably from about 0.05% to about 10% by weight, more preferably from about 0.1% to about 5% by weight, and most preferably from about 0.3% to about 1% by weight of the above-mentioned 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 greater than 10, more preferably greater than 11, most preferably greater than 12, in particular 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, i.e. component A and component B, is selected such that the ratio of water to alumina cement (W / CAC) or the ratio of 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+CaSO )) 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. 4 )) is less than 0.35.

[0052] Furthermore, it is particularly preferred that the proportion of lithium in component A is selected such 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) are 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 such that the ratio of calcium aluminate cement with calcium sulfate to lithium sulfate monohydrate in the product obtained by mixing components A and B ((CAC+CaSO4) / Li 2 SO 4 xH 2 O) is selected to be 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 such 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 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% by weight of a plasticizer, 0.001 to 0.05% by weight 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, further 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 / bactericide are added and the mixture is homogenized; an 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; finally, an accelerator and a thickener are added and mixed until the mixture is completely homogenized.

[0057] Component B used in the present invention may be prepared as follows: the activator is dissolved in deionized water, followed by addition of retarder and thickener and optionally mineral filler with 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 fluidic 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 thickening agents 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 produced separately, components A and B are introduced into separate containers from which they are discharged by a mechanical device and led 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 in 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 drilling hole. The assembly in a set of multiple chamber cartridges or pails or buckets is also possible.

[0064] The hardenable alumina cement composition exiting 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 sets and hardens. In particular, inorganic mortar systems should be considered for the chemical fastening of the fastening means and the 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, in particular threaded rods, bolts, steel reinforcements, etc., into mineral substrates such as masonry, 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 for accelerating 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 applied in the 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.

[0069] Furthermore, an inorganic mortar system containing at least one alkali metal salt and / or alkaline earth metal salt can be used, in particular, for the attachment of fibers, scrims, fabrics, or composites, particularly highly elastic fibers, preferably carbon fibers, for the reinforcement of building structures such as walls or ceilings or floors, or furthermore, for the attachment of components such as plates or blocks, for example, made of stone, glass, or plastic, to a building or structural element. However, in particular, the inorganic mortar system is used for the attachment of fastening means, preferably anchor rods, particularly threaded rods, bolts, metal elements such as steel reinforcements, etc., into recesses such as drilled holes in a mineral substrate such as a structure made of bricks, concrete, permeable concrete, or natural stone, whereby the components of the two-component inorganic mortar system are pre-mixed, for example, by means of a static mixer, or by breaking a cartridge or plastic bag, or by mixing the components of a multi-chamber pail or bucket set.

Mode for Carrying Out the Invention

Examples

[0070] The following examples illustrate the present invention but do not limit the present invention thereby. 1. Preparation of Component A and Component B The cementitious component A and the initiator component B of Comparative Examples 1 and 2 and Examples 1 and 2 of the present invention are first produced by mixing the components specified in Tables 1 and 2, respectively. The given ratios are expressed in weight %.

[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 calcium aluminate cement (81.00 grams, pure Ternal White®) was then added in small portions while stirring with a dissolver to finally obtain a smooth liquid paste-like slurry of blocked cement in water with a pH of less than 7. After the addition of calcium aluminate cement, in the present embodiment, 0.15 grams of lithium sulfate was added, followed by 0.5 grams of xanthan gum (thickener) and homogenizing the slurry. Alternatively, the accelerator can be added in advance to the liquid phase.

[0072] [Table 1]

[0073] 1.2 Component B In each amount of deionized water, add 4.0 grams of NaOH pellets (activator), 0.65 grams of Ecodis® P50 (superplasticizer), 0.4 grams of Optigel® WX (thickener), and optionally 0.43 grams of Li 2 SO 4 (accelerator), 1.93 grams of citric acid and 1.20 grams of tartaric acid were dissolved. While stirring in a dissolver, the mixture of fillers 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 fillers 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 rigid cartridges with a mixing ratio of A:B component=3:1. The rigid cartridges were placed in a dispenser and injected into a drilled hole in a concrete plate. The drilled hole showed a depth of 72 mm and a diameter of 14 mm. Before injecting the mortar, the drilled hole was cleaned by compressed air washing and brushing. Then, a threaded rod of steel grade 12.9 was inserted into the drilled hole. The pull-out strength was measured after different curing times to determine the improved curing behavior of the examples of the invention. Each series consisted of four pull-out values ​​per curing time. The results of the pull-out tests 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 significantly improve the load values ​​after 18 and 24 hours of hardening compared to systems where the accelerator compound is present in the B component. This shows that the addition of at least one alkali metal salt and / or alkaline earth metal salt accelerator (especially as shown for the Li accelerator) to the A component, even when used in very low concentrations, results in a more uniform distribution in 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 lithium sulfate in a two-component inorganic mortar system for chemical fastening of fastening means in a mineral substrate (material to be fastened) to accelerate the hardening of the cement, comprising a settable alumina cement component A and an initiator component B for initiating 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, component B comprising an activator, and wherein the lithium sulfate for accelerating the hardening of the cement is comprised in the settable alumina cement component A of the inorganic mortar system.

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

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

4. 3. The use according to claim 1 or 2, 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.

5. 3. The use according to claim 1 or 2, wherein the activating agent comprises only sodium hydroxide.

6. 3. The use according to claim 1 or 2, wherein the lithium sulfate for accelerating the hardening of the cement is in the product obtained by mixing components A and B and is present in the range of about 0.05% to 10.0% by weight.

7. 3. The use according to claim 1 or 2, wherein the fastening means is an anchor rod, a threaded anchor rod, a bolt or a steel reinforcement.

8. 3. Use according to claim 1 or 2, wherein the mineral substrate is a structure made of brickwork, concrete, pervious concrete or natural stone.

9. 3. Use according to claim 1 or 2 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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