A stabilized aqueous composition based on blocked granulated blast furnace slag for initiating the setting and hardening of an alumina cement composition.

Abstract

The present invention relates to a long-term stabilized aqueous initiator composition for initiating the setting and hardening of an alumina cement composition, comprising blocked granulated blast furnace slag, a thickener, water, and optionally at least one mineral filler, a method for preparing the long-term stabilized aqueous initiator composition, and the use of the composition in a system for chemically fixing an anchoring means in a mineral substrate.

Description

Technical Field

[0001] The present invention relates to a long-term stabilized aqueous initiator composition for initiating the setting and hardening of an alumina cement composition. In particular, the long-term stabilized aqueous initiator composition comprises blocked granulated blast furnace slag, a thickener, water, and optionally at least one mineral filler. The invention further relates to a method for preparing the long-term stabilized aqueous initiator composition, and to the use of said composition in a system for chemically fixing fastening means, preferably metallic elements, in mineral substrates such as structures made of brickwork, concrete, pervious concrete or natural stone.

Background Art

[0002] Aqueous compositions, in particular aqueous suspensions, are heterogeneous mixtures containing solid particles which are sufficiently large to sediment and are in approximately fluid or paste form. The advantage of such suspensions is that they form a ready-to-use solution which can be used directly for any application for construction chemistry, such as the chemical fixing of fastening means, preferably metallic elements such as anchor rods, in particular threaded rods, bolts, steel reinforcements, in recesses such as boreholes in mineral substrates such as structures made of brickwork, concrete, pervious concrete or natural stone.

[0003] Where rapid hardening is desired, organic systems based on free-radically polymerizable resins are used. However, it is known that such systems are generally contaminating, expensive, can be dangerous and / or toxic to the environment and to persons handling them, and they often require special labeling.

[0004] To overcome these drawbacks, alumina cement-based systems, primarily composed of minerals, have been developed. Alumina cement, with monocalcium aluminate as its main component, is widely used in the building and construction industries because the final product exhibits high levels of mechanical performance over long periods. Furthermore, alumina cement is resistant to bases, achieves maximum strength more quickly than Portland cement, and can withstand sulfate solutions. Therefore, alumina cement systems are preferred for use in the field of chemical fixation.

[0005] In particular, there are many two-component mortar systems, sometimes referred to as kits of parts, in which each component is mixed before use or during application to initiate the curing process and is intended to provide good chemical fixation of the adhesive means in a mineral substrate. One component provides a stabilized cementitious composition, and then another component initiates its setting and hardening.

[0006] Additives for setting and hardening alumina cement are known from the prior art. For example, U.S. Patent No. 3,826,665 describes an auxiliary composition for improving the setting and hardening properties of alumina cement.

[0007] German Patent No. 2311239 describes an auxiliary composition for improving the setting and hardening properties of alumina cement and mortar, comprising lithium, a water-soluble lithium salt, and a hydroxylated organic acid or its salt or ester. This fluid may be directly incorporated into alumina cement or mortar and concrete during their manufacture, or added to the mixed water during application. However, a drawback of this system is that the activator composition cannot be stored for a sufficient period of time to be readily available, and therefore must be freshly prepared before use according to the desired setting and hardening time, resulting in more steps before application. Furthermore, the lithium-based activator component is expensive, and its extraction presents many problems from humanitarian, economic, and political standpoints, resulting in high carbon dioxide emissions.

[0008] With regard to the chemical fixation of adhesives to mineral substrates, rapid curing times, i.e., less than 5 minutes, are not necessarily desirable. Furthermore, most known systems lack sufficient fluidity for most practical applications of the resulting compositions. Often, such prior art compositions also tend to crack relatively quickly or fail to exhibit the required mechanical properties even under the influence of increased temperature. Moreover, these systems cannot be stored for extended periods before use.

[0009] Therefore, there is a need for a long-term stabilized aqueous initiator composition for initiating the setting and hardening of alumina cement compositions that is superior to prior art systems in terms of environmental impact, health and safety, handling, storage time, and a good balance between setting and hardening of mortar during application. Furthermore, there is interest in providing a long-term stabilized aqueous initiator composition that can be used in multi-component systems for chemically fixing adhesive means in mineral substrates without adversely affecting the handling, characteristics, and mechanical performance of the chemical fixing system. There is also interest in reducing the water-to-cement ratio and conversion used in the system, which can lead to a decrease in performance over time. Finally, there is a need for a long-term stabilized aqueous initiator composition with low carbon dioxide emissions.

[0010] In view of the above, the object of the present invention is to provide a long-term stable aqueous initiator composition that overcomes the shortcomings of prior art compositions. In particular, the object is to provide a long-term stable aqueous initiator composition that is ready for immediate use, easy to handle, environmentally friendly, can be stored stably for a certain period before use, exhibits a good balance between setting and hardening, still provides excellent mechanical performance of the system with respect to chemically fixing the fixing means even under the influence of rising temperatures during application, has low carbon dioxide emissions, and reduces the water-to-cement ratio and conversion used in the system.

[0011] Furthermore, an object of the present invention is to provide a method for preparing a long-term stable aqueous initiator composition, which can be used in a multi-component system, is cost-effective, environmentally friendly, easy to implement, stable, and easy to apply.

[0012] In addition, it is also an objective to provide an easily implementable method for activating the setting and hardening of curing-type aqueous alumina cement components, which can be used in the field of chemically fixing adhesive means in mineral substrates.

[0013] Furthermore, an object of the present invention is to provide a long-term stabilizing aqueous initiator composition that can be used as a fixing means, preferably a multi-component system, particularly a two-component system, for chemically fixing metal elements in mineral substrates such as brickwork, concrete, permeable concrete, or structures made of natural stone.

[0014] These and other objectives, which will become apparent from the description that ensures the invention is correct, are addressed by the invention as described in the independent claims. Dependent claims relate to preferred embodiments.

[0015] Summary of the Invention In one embodiment, the present invention provides a long-term stabilizing aqueous initiator composition for initiating the setting and hardening of an alumina cement composition, which is stable over a certain period of time at room temperature and at elevated temperatures. In particular, the long-term stabilizing aqueous initiator composition comprises blocked granulated blast furnace slag, a thickener, water, and optionally at least one mineral-based filler.

[0016] In another aspect, the present invention provides a method for preparing the long-term stabilized aqueous initiator composition.

[0017] In yet another aspect, the present invention provides a method for activating the setting and hardening of a curing aqueous alumina cement component using the long-term stabilizing aqueous initiator composition.

[0018] In yet another aspect, the present invention provides a long-term stabilizing aqueous initiator composition that can be used in multi-component systems, particularly two-component systems, for chemically fixing, preferably metal elements, in mineral substrates such as structures made of brickwork, concrete, permeable concrete, or natural stone. [Modes for carrying out the invention]

[0019] The following terms and definitions are used in the context of this invention.

[0020] When used in the context of this invention, the singular forms of "a" and "an" also include their respective plural forms unless otherwise explicitly indicated by the context. Therefore, the terms "a" or "an" are intended to mean "one or more" or "at least one" unless otherwise stated.

[0021] In the context of this invention, the term "alumina cement" refers primarily to calcium aluminate cement consisting of hydrated activated calcium aluminate. Other names include "high-alumina cement" or, in French, "Ciment fondu." The main active ingredient in calcium aluminate cement is monocalcium aluminate (CaAl2O4, CaO·Al2O3, or CA in cement chemical notation).

[0022] In the context of the present invention, the term "shelf life" refers to the time that the components remain in the form of an aqueous composition which is approximately fluid, without the solid product condensing or losing its reactivity, and can be returned to the aqueous composition by mechanical means.

[0023] In the context of this invention, the term "initiator" refers to a compound or composition that modifies the chemical environment to initiate a specific chemical reaction. In this invention, the initiator modifies the pH value of the mortar composition, thereby deblocking the hydraulic binder in the final mixture.

[0024] In the context of the present invention, the term "binder" or "binder component" refers to a calcium aluminate-based cementitious constituent and other optional additional components such as, for example, fillers. In particular, the term "main binder component" refers to component A.

[0025] In the context of the present invention, the term "stable" or "stabilized" means that the viscosity and pH value of the aqueous initiator composition do not change significantly during storage, and the composition does not set or harden.

[0026] In the context of the present invention, the term "long-term stabilized aqueous initiator composition" is also referred to as component B with respect to a two-component mortar system.

[0027] Surprisingly, the inventors have found that a long-term stabilized aqueous initiator composition based on blocked ground-granulated blast-furnace slag (GGBFS) can be used to activate an aqueous slurry comprising a blocked alumina component as the main binder component in inorganic mortar systems.

[0028] Conventional calcium aluminate-based binders rely on synthetic or mined carbonate sources to mitigate strength loss due to the conversion phenomenon, whereas ground-granulated blast-furnace slag is a waste product from steel production and is therefore inexpensive and has low carbon dioxide emissions when reused as a binder. Blocking ground-granulated blast-furnace slag with sugars such as gluconate in water achieves an alkaline pH that can be used to activate blocked calcium aluminate cement components. Therefore, no separate activator such as sodium hydroxide or lithium hydroxide is required. The alkaline pH generated from the hydration of calcium aluminate cement subsequently activates the ground-granulated blast-furnace slag.

[0029] In addition, it has been found that in particular the use of ground-granulated blast-furnace slag is more sustainable compared to the use of conventional Portland cement, and also has lower carbon dioxide emissions than synthetic resins.

[0030] The present invention relates to a long-term stabilized aqueous initiator composition comprising blocked granulated blast furnace slag, a thickener, water, and optionally at least one mineral filler.

[0031] The granulated blast furnace slag preferably comprises 30 to 45% by weight of calcium oxide (CaO), 30 to 45% by weight of silicon dioxide (SiO₂), 1 to 15% by weight of aluminum oxide (Al₂O₃), 4 to 17% by weight of magnesium oxide (MgO), and 0.5 to 1% by weight of sulfur (S). Further characteristic components contained in the granulated blast furnace slag are iron oxide (Fe₂O₃), sodium oxide (Na₂O), potassium oxide (K₂O), chloride, sulfur trioxide (SO₃), and manganese oxide (Mn₂O₃), which preferably account for less than 5% by weight of the granulated blast furnace slag.

[0032] Based on the total weight of the long-term stabilized aqueous initiator composition of the present invention, the long-term stabilized aqueous initiator composition comprises at least about 5% by weight, preferably at least about 10% by weight, more preferably at least about 20% by weight, most preferably at least about 30% by weight; and from about 5% by weight to about 80% by weight, preferably from about 10% by weight to about 70% by weight, more preferably from about 20% by weight to about 60% by weight, most preferably from about 30% by weight to about 55% by weight of granulated blast furnace slag.

[0033] The blocked granulated blast furnace slag in the present long-term stabilized aqueous initiator composition comprises granulated blast furnace slag and a blocking agent. The blocking agent for granulated blast furnace slag is selected from the group consisting of gluconic acid, glycolic acid, phosphonic acid, salts and esters thereof, glucose, and mixtures thereof. Preferably, the blocking agent is a gluconate, more preferably sodium gluconate.

[0034] The long-term stabilized aqueous initiator composition 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, most preferably at least about 1.0% by weight, about 0.01% to about 25% by weight, preferably about 0.05% to about 20% by weight, more preferably about 0.1% to about 15% by weight, and most preferably about 1.0% to about 10% by weight of the blocking agent. In the most preferred embodiment, the long-term stabilized aqueous initiator composition contains about 0.2% to about 0.4% by weight of sodium gluconate, based on the total weight of the long-term stabilized aqueous initiator composition.

[0035] This long-term stabilized aqueous initiator composition further comprises a thickening agent. The thickening agent used in the present invention may be selected from the group consisting of bentonite, silicon dioxide, quartz, acrylate-based thickening agents such as alkali-soluble or alkali-swelling emulsions, fumed silica, clay, and titanate chelating agents. Polyvinyl alcohol (PVA), hydrophobically modified alkali-soluble emulsion (HASE), hydrophobically modified ethylene oxide urethane polymers known in the art as HEUR, and cellulosic thickeners, such as hydroxymethyl cellulose (HMC), hydroxyethyl cellulose (HEC), hydrophobically-modified hydroxyethyl cellulose (HMHEC), sodium carboxymethyl cellulose (SCMC), sodium carboxymethyl 2-hydroxyethyl cellulose, 2-hydroxypropyl methylcellulose, 2-hydroxyethyl methylcellulose, 2-hydroxybutyl methylcellulose, 2-hydroxyethyl ethylcellulose, 2-hydroxypropyl cellulose, attapulgite clay, and mixtures thereof are exemplified. Suitable thickeners include commercially available products such as Optigel WX (BYK-Chemie GmbH, Germany), Rheolate 1 (Elementis GmbH, Germany), Cellosize (trademark), and Acrysol ASE-60 (The Dow Chemical Company).Component B contains, based on the total weight of the long-term stabilized aqueous initiator composition, at least about 0.01% by weight, preferably at least about 0.05% by weight, more preferably at least about 0.1% by weight, most preferably at least about 0.3% by weight, about 0.01% to about 15% by weight, preferably about 0.05% to about 10% by weight, more preferably about 0.1% to about 5% by weight, and most preferably about 0.1% to about 1% by weight of the thickening agent.

[0036] In preferred embodiments, the long-term stabilizing aqueous initiator composition may also contain a cellulosic thickener, such as hydroxymethylcellulose (HMC) or hydroxyethylcellulose (HEC).

[0037] The long-term stabilized aqueous initiator composition may optionally contain at least one mineral filler. Mineral fillers that can be used in the present invention may include limestone fillers, such as calcite, sand, corundum, dolomite, alkali-resistant glass, crushed stone, gravel, pebbles, quartz, quartz powder, quartz sand, clay, fly ash, fumed silica, brick powder, rice husk ash, phonolite, calcined clay and metakaolin, carbonate compounds, pigments, titanium dioxide, lightweight fillers, gypsum, or mixtures thereof. Suitable fillers are commercially available products. The long-term stabilized aqueous initiator composition may contain at least about 1% by weight, preferably at least about 10% by weight, more preferably at least about 20% by weight, and most preferably at least about 30% by weight of the said at least one filler, based on the total weight of the long-term stabilized aqueous initiator composition. The at least one mineral filler contained in the long-term stabilized aqueous initiator composition according to the present invention is preferably a mixture of mineral fillers.

[0038] In advantageous embodiments, the long-term stabilized aqueous initiator composition further comprises, alone or in combination, the following properties:

[0039] This long-term stabilized aqueous initiator composition may also contain a plasticizer. The plasticizer may be selected from the group consisting of flowables from the families of low molecular weight (LMW) polyacrylic acid polymers, polyphosphonate polyoxes, and polycarbonate polyoxes, and Ethacryl flowables from the polycarboxylate ether group, and mixtures thereof, for example, Ethacryl® G (Coatex, Arkema Group, France), Acumer® 1051 (Rohm and Haas, UK), or Sika® ViscoCrete®-20 HE (Sika, Germany). Suitable plasticizers are commercially available products. Component B may contain, based on the total weight of the long-term stabilizing aqueous initiator composition, at least about 0.2% by weight, preferably at least about 0.3% by weight, more preferably at least about 0.4% by weight, most preferably at least about 0.5% by weight, about 0.2% to about 20% by weight, preferably about 0.3% to about 15% by weight, more preferably about 0.4% to about 10% by weight, and most preferably about 0.5% to about 5% by weight of the plasticizer.

[0040] The water content in this long-term stabilized aqueous initiator composition is, based on the total weight of the long-term stabilized aqueous initiator composition, at least about 1% by weight, preferably at least about 5% by weight, more preferably at least about 10% by weight, most preferably at least about 20% by weight, about 1% to about 50% by weight, preferably about 5% to about 40% by weight, more preferably about 10% to about 30% by weight, and most preferably about 15% to about 25% by weight.

[0041] The presence of plasticizers and thickeners does not alter the overall inorganic properties of this long-term stabilized aqueous initiator composition.

[0042] Furthermore, when this long-term stabilizing aqueous initiator composition is used as an initiator for alumina cement components, it may also contain an accelerator component. The accelerator component consists of at least one alkali and / or alkaline earth metal salt selected from the group consisting of hydroxides, chlorides, sulfates, phosphates, monohydrogen phosphates, dihydrogen phosphates, nitrates, carbonates, and mixtures thereof. Preferably, the accelerator component is an alkali or alkaline earth metal salt, more preferably a water-soluble alkali or alkaline earth metal salt, more preferably a calcium metal salt such as calcium hydroxide, calcium sulfate, calcium carbonate, calcium chloride, calcium formate, or calcium phosphate; a sodium metal salt such as sodium hydroxide, sodium sulfate, sodium carbonate, sodium chloride, sodium formate, or sodium phosphate; or a lithium metal salt such as lithium hydroxide, lithium sulfate, lithium sulfate monohydrate, lithium carbonate, lithium chloride, lithium formate, or lithium phosphate, most preferably lithium sulfate or lithium sulfate monohydrate. The long-term stabilized aqueous initiator composition may contain, based on the total weight of the long-term stabilized aqueous initiator composition, at least about 0.01% by weight, preferably at least about 0.05% by weight, more preferably at least about 0.1% by weight, most preferably at least about 1.0% by weight, about 0.01% to about 25% by weight, preferably about 0.05% to about 20% by weight, more preferably about 0.1% to about 15% by weight, and most preferably about 1.0% to about 10% by weight of the accelerator.

[0043] This long-term stabilized aqueous initiator composition, comprising an initiator and a retarder, exists in the aqueous phase, preferably in the form of a slurry or paste.

[0044] The pH value of this long-term stable aqueous initiator composition is preferably in the range of 10 or greater, more preferably greater than 11, most preferably greater than 12, particularly between 10 and 14, and preferably between 11 and 13.

[0045] In a preferred embodiment, component B comprises or consists of the following components: 45% to 55% by weight of blast furnace granulated slag, Blocking agent for 0.1-0.5% by weight granulated blast furnace slag. 0.01% to 0.5% by weight of a thickening agent, Optionally, 10-30% by weight of at least one mineral-based filler, Optionally, 0.5 to 1.5% by weight of a plasticizer, and 15% to 30% by weight of water, Optionally, 0.01% to 5% by weight of lithium sulfate or lithium sulfate monohydrate.

[0046] In the most preferred embodiment, component B comprises or consists of the following components: 45% to 55% by weight of blast furnace granulated slag, 0.1-0.5% by weight of sodium gluconate, 0.01% to 0.5% by weight of hydroxymethylcellulose or hydroxyethylcellulose Optionally, 10-30% by weight of at least one mineral-based filler, Optionally, 0.5 to 1.5% by weight of a plasticizer, and 15% to 30% by weight of water, Optionally, 0.01% to 5% by weight of lithium sulfate or lithium sulfate monohydrate.

[0047] The long-term stabilized aqueous initiator composition according to the present invention can be prepared as follows: optionally, a plasticizer and a thickener are mixed with water, and then blast furnace granulated slag and optionally a filler are added stepwise while increasing the stirring speed until the mixture is homogeneous. Finally, optionally, an accelerator component may be added until the mixture is completely homogeneous. Thus, a method for preparing the long-term stabilized aqueous initiator composition according to the present invention includes the following steps: i) The process of introducing water into a mixing tank, ii) Optionally, a step of dissolving a thickening agent and optionally a plasticizer under stirring and adding them, iii) Optionally, while increasing the stirring speed, disperse and add granulated blast furnace slag and optionally packing material. vi) Continue stirring until completely homogenized.

[0048] The long-term stabilized aqueous initiator composition was stored in a sealed container at ambient temperature and 20°C to prevent water evaporation, and all changes in fluidity, homogeneity (indicator of sedimentation), and pH value were evaluated at several time intervals, i.e., 1 week, 4 weeks, 3 months, and 6 months. The properties of all components remained unaffected even after 6 months, and the composition showed a shelf life of at least 1 week, preferably at least 4 weeks, more preferably at least 3 months, and most preferably at least 6 months at ambient temperatures up to 20°C.

[0049] This long-term stabilizing aqueous initiator composition can be used in methods for activating the setting and hardening of curing-type aqueous phase alumina cement components.

[0050] The method according to the present invention is i) A step of adding the above-mentioned long-term stabilized aqueous initiator composition to the aqueous phase alumina cement component, and ii) including the step of mixing it.

[0051] Preferably, the cement component to which this long-term stabilizing aqueous initiator composition can be added is based on aqueous calcium aluminate cement (CAC) or aqueous calcium sulfoaluminate cement (CAS). The calcium aluminate cement that can be used is characterized by rapid setting and hardening, rapid drying and shrinkage compensation when mixed with calcium sulfate, and excellent corrosion resistance and shrinkage resistance. A suitable calcium aluminate cement for use is, for example, Ternal® White (Kerneos, France).

[0052] In particular, the cement component may contain, based on the total weight of the cement component, at least about 40% by weight, preferably at least about 50% by weight, more preferably at least about 60% by weight, most preferably at least about 70% by weight, about 40% to about 95% by weight, preferably about 50% to about 90% by weight, more preferably about 60% to about 85% by weight, and most preferably about 70% to about 80% by weight of calcium aluminate.

[0053] Alternatively, the cement component comprises, based on the total weight of component A, at least about 20% by weight, preferably at least about 30% by weight, more preferably at least about 40% by weight, most preferably at least at least about 50% by weight, about 20% to about 80% by weight, preferably about 30% to about 70% by weight, more preferably about 35% to about 60% by weight, most preferably about 40% to about 55% by weight of alumina cement, and, based on the total weight of the cement component, at least about 5% by weight, preferably at least about 10% by weight, more preferably at least at least about 15% by weight, most preferably at least 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. The CaSO4 / CAC ratio of the cement component shall be 35:65 or less.

[0054] Preferably, the cement components are blocked by a blocking agent selected from the group consisting of boric acid, carboxylic acid, phosphoric acid, metaphosphoric acid, phosphorous acid, phosphonic acid, and salts thereof. 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%.

[0055] The cement components may further contain the following properties, either individually or in combination. The plasticizers that may be included in the cement components may be selected from the group consisting of flowlubbers from the families of low molecular weight (LMW) polyacrylic acid polymers, polyphosphonate polyoxes, and polycarbonate polyoxes, and Ethacryl flowlubbers from the polycarboxylate ether group, and mixtures thereof, for example, Ethacryl® G (Coatex, Arkema Group, France), Acumer® 1051 (Rohm and Haas, UK), or Sika® ViscoCrete®-20 HE (Sika, Germany). Suitable plasticizers are commercially available products.

[0056] The cement components may also contain additional thickeners. The thickeners that can be used may be selected from the group consisting of xanthan gum, gellan gum, or DIUTAN® gum (CPKelko, USA), mineral products such as starch-derived ethers, guar-derived ethers, polyacrylamide, carrageenan, agar, and clay, as well as organic products such as mixtures thereof. Suitable thickeners are commercially available products.

[0057] The cement components may further contain antimicrobial or biocide agents. The antimicrobial or biocide agents that can be used may be selected from the group consisting of compounds of the isothiazolinone family, such as methylisothiazolinone (MIT), octylisothiazolinone (OIT), and benzoisothiazolinone (BIT), and mixtures thereof. Suitable antimicrobial or biocide agents are commercially available products. Ecocide K35R (Progiven, France) and Nuosept OB03 (Ashland, The Netherlands) are mentioned as examples.

[0058] The cement components may also include at least one filler, particularly an organic or mineral filler. The fillers that can be used may be selected from the group consisting of quartz powder, preferably quartz powder having an average particle size (d50%) of about 16 μm, silica sand, clay, fly ash, fumed silica, carbonate compounds, pigments, titanium dioxide, lightweight fillers, and mixtures thereof. Suitable mineral fillers are commercially available products. Quartz powder Millisil W12 or W6 (Quarzwerke GmbH, Germany) is mentioned as an example.

[0059] The water content in the cement components may be at least about 1% by weight, preferably at least about 5% by weight, more preferably at least about 10% by weight, most preferably at least about 20% by weight, about 1% to about 50% by weight, preferably about 5% to about 40% by weight, more preferably about 10% to about 30% by weight, and most preferably about 15% to about 25% by weight, based on the total weight of the cement components.

[0060] The presence of plasticizers, thickeners, and antimicrobial or biocides does not alter the overall inorganic properties of the cement components.

[0061] Furthermore, the cement component may also contain an accelerator component. The accelerator component consists of at least one alkali and / or alkaline earth metal salt selected from the group consisting of hydroxides, chlorides, sulfates, phosphates, monohydrogen phosphates, dihydrogen phosphates, nitrates, carbonates, and mixtures thereof. Preferably, the accelerator component is an alkali or alkaline earth metal salt, more preferably a water-soluble alkali or alkaline earth metal salt, more preferably a calcium metal salt such as calcium hydroxide, calcium sulfate, calcium carbonate, calcium chloride, calcium formate, or calcium phosphate; a sodium metal salt such as sodium hydroxide, sodium sulfate, sodium carbonate, sodium chloride, sodium formate, or sodium phosphate; or a lithium metal salt such as lithium hydroxide, lithium sulfate, lithium sulfate monohydrate, lithium carbonate, lithium chloride, lithium formate, or lithium phosphate, most preferably lithium sulfate or lithium sulfate monohydrate. The cement component may contain, based on the total weight of the cement component, at least about 0.01% by weight, preferably at least about 0.05% by weight, more preferably at least about 0.1% by weight, most preferably at least about 1.0% by weight, about 0.01% to about 25% by weight, preferably about 0.05% to about 20% by weight, more preferably about 0.1% to about 15% by weight, and most preferably about 1.0% to about 10% by weight of the accelerator.

[0062] The cement component to which this long-term stabilized aqueous initiator composition can be added, which includes alumina cement or calcium sulfoaluminate cement, is preferably present in the aqueous phase, most preferably in the form of a slurry or paste.

[0063] The long-term stabilized aqueous initiator composition according to the present invention is used in a mortar system containing a curing-type aqueous alumina cement component. In particular, this long-term stabilized aqueous initiator composition is used as the first component in a two-component mortar system containing a curing-type aqueous alumina cement component. Preferably, the use of the long-term stabilized aqueous initiator composition according to the present invention yields a two-component mortar system having an initial setting time of at least 5 minutes.

[0064] In particular, the long-term stabilizing aqueous initiator composition according to the present invention is used to activate the setting and hardening of a curing aqueous alumina cement component used to chemically fix a fixing means in a mineral substrate. Preferably, the fixing means is an anchor rod, a threaded anchor rod, a bolt, or a steel reinforcement. The mineral substrate to which the fixing means is chemically fixed is a structure made of brickwork, concrete, permeable concrete, or natural stone.

[0065] Furthermore, the long-term stabilizing aqueous initiator composition according to the present invention may be used in an inorganic mortar system as a coating, or particularly for attaching fibers, scrim, cloth, or composite materials, especially highly elastic fibers, preferably carbon fibers, for reinforcement of building structures, such as walls, ceilings, or floors, or even further for installing components such as plates or blocks made of stone, glass, or plastic onto buildings or structural elements.

[0066] The following examples illustrate the present invention, but do not limit it thereto. [Examples]

[0067] 1. Preparation of long-term stable aqueous initiator composition This long-term stabilized aqueous initiator composition is first prepared by mixing the components specified in Table 1. The given proportions are expressed in weight percent.

[0068] An exemplary preparation of component B is as follows: 1.0 g of Ecodis® P50 (plasticizer), 0.1 g of Cellosize® QP-100 MH (thickener), and 0.22 g of sodium gluconate (blocking agent) were dissolved in 21.00 g of deionized water. While stirring in a dissolving machine, 50 g of blast furnace granulated slag, 17 g of sand, and 10.68 g of Betocarb UF were added with vigorous stirring until a smooth, solid-in-water liquid paste slurry with a pH greater than 11 was finally obtained.

[0069] [Table 1]

[0070] 2. Stability monitoring of long-term stabilized aqueous initiator compositions The long-term stabilized aqueous initiator compositions B0 and B1 were stored in sealed containers at ambient temperature and 20°C to prevent water evaporation. After several time intervals, i.e., 1 week, 4 weeks, 3 months, and 6 months, all changes in fluidity, homogeneity, and pH value were evaluated. Initiation ability was also tested.

[0071] Measuring pH is a good method for monitoring the stability of aqueous compositions, i.e., suspensions. This long-term stabilizing aqueous initiator composition is considered unstable if its pH value changes significantly.

[0072] Homogeneity assessment is a good method for monitoring the stability of aqueous compositions, i.e., suspensions. This long-term stabilizing aqueous initiator composition is considered unstable if it begins to harden and settle. Homogeneity assessment is used as an indicator of settling.

[0073] The properties of the aqueous initiator composition of the present invention, particularly the properties of all components, remained unaffected even after 6 months; therefore, the shelf life is at least 6 months at ambient temperature and 20°C. The pH value remained above 12. The initiation ability remained complete compared to newly generated components B0 or ​​B1.

[0074] 3. Initiation of the curing-type aqueous alumina cement component The initiation ability of the long-term stabilizing aqueous initiator compositions of the present invention was evaluated by activating the setting and hardening of the curing-type aqueous alumina cement component, which includes a step of adding long-term stabilizing aqueous initiator compositions B0 and B1 to the aqueous alumina cement component (composition A, Table 2) and mixing them.

[0075] The aqueous alumina cement component (A) is first produced by mixing the constituent components specified in Table 2. The given proportions are expressed in weight percent.

[0076] Specifically, 19.48 grams of deionized water, 0.75 grams of 85% phosphoric acid (blocking agent), 0.6 grams of Ethacryl G (high-flow agent), and 0.02 grams of Nuosept® (biocide) were homogenized at room temperature. While stirring in a dissolving machine, calcium aluminate cement (78.50 grams, pure Ternal White®) was added in small amounts sequentially until a smooth liquid paste slurry of blocked cement in water with a pH of less than 7 was finally obtained. After the addition of calcium aluminate cement, 0.15 grams of lithium sulfate monohydrate and 0.5 grams of xanthan gum (thickener) were added, and the slurry was homogenized at 2500 rpm for 5 minutes.

[0077] [Table 2]

[0078] After being prepared separately, the aqueous alumina cement component and the long-term stabilizing aqueous initiator composition are mixed in a high-speed mixer in a volume ratio of 3:1, and the initial setting time of the resulting mortar system is measured by thermal flux calorimetry.

[0079] When the aqueous initiator composition of the present invention is added to the aqueous alumina cement component, a mortar system is obtained in which the initial setting time is at least 5 minutes, and particularly in the range of about 5 to 25 minutes.

[0080] 4. Determination of Mechanical Performance After preparation, binder component A and its respective component B were filled into separate chambers of a two-component plastic hard cartridge in the specified ratio of A:B = 3:1. The hard cartridge was placed in a dispenser, a static mixer was attached, the mortar was poured into a steel sleeve, and a threaded rod (M8) was inserted. The steel sleeve was 28 mm deep and 10 mm in diameter. After a certain curing time, the pull-out strength was measured to assess the improvement in the mortar's performance over the curing time. The ultimate breaking load was calculated as the bond strength and is shown in Table 3 in N / mm². 2 Shown in units.

[0081] [Table 3]

[0082] Table 3 shows that when a slurry of blocked slag is mixed with a slurry of blocked aluminate, an increased load value can be achieved within 24 hours of curing. A ratio of A:B = 1:3 to 6:1 is preferred, more preferably 1:1 to 5:1, even more preferably 2:1 to 4:1, and most preferably A:B = 3:1.

[0083] The aqueous initiator composition of the present invention has a long lifespan, i.e., a shelf life; that is, when stored at ambient temperature, the aqueous initiator composition does not condense at ambient temperature for a period ranging from several weeks to several months, i.e., at least one week, preferably at least four weeks, more preferably at least three months, and most preferably at least six months, and as a result is protected from any delays in storage or delivery. The aqueous initiator composition of the present invention remains in a slurry state and does not separate, especially during transport, thus ensuring on-site implementation. Furthermore, the composition has low toxicity and ecotoxicity.

[0084] When a curing-type aqueous alumina cement component is initiated with the aqueous initiator composition of the present invention, it provides curing speed and mechanical strength comparable to organic systems, but its essentially mineral composition results in significantly lower toxicity than known systems of the prior art, leading to much less environmental pollution and enabling cost-effective production.

[0085] Furthermore, it was shown that a system based on an aqueous slurry containing a blocked alumina component as the main binder and blocked granulated blast furnace slag (GGBFS) in an alkaline pH aqueous slurry as the second binder allows for a lower water-to-cement ratio compared to state-of-the-art two-component injection mortars containing a filler-based activator component. In addition, it was shown that the reduction in long-term strength due to conversion, which is characteristic of calcium aluminate cement, can be mitigated by blending these two cements to produce a stable Stratlingite hydrate phase, because the slag provides a source of reactive silicate.

[0086] Advantageously, blast furnace granulated slag, a waste product from steel production and therefore a low-carbon alternative with low carbon dioxide emissions when reused as a binder, has proven to be usable in inorganic fixation systems.

[0087] Furthermore, it has been shown that mortar systems containing the aqueous initiator composition of the present invention do not contain any harmful substances while maintaining standards for chemical bonding applications, thus also encompassing reductions in carbon dioxide emissions and labeling. In addition, it has been shown that the use of aqueous initiator compositions containing blocked blast furnace granulated slag is more sustainable than the use of conventional Portland cement and has lower carbon dioxide emissions than synthetic resins.

Claims

1. A long-term stabilizing aqueous initiator composition for initiating the setting and hardening of an alumina cement composition, comprising blocked granulated blast furnace slag, a thickener, water, and at least one mineral-based filler, The long-term stabilized aqueous initiator composition is 45% to 55% by weight of blast furnace granulated slag, A blocking agent for the blast furnace granulated slag in an amount of 0.1 to 0.5% by weight, 0.01% to 0.5% by weight of a thickening agent, 10 to 30% by weight of at least one mineral-based filler, 0.01% to 25% by weight of accelerator, 0.5 to 1.5% by weight of a plasticizer, and 15% to 30% by weight of water, Optionally, it contains 0.01% to 5% by weight of lithium sulfate or lithium sulfate monohydrate. The blocked granulated blast furnace slag comprises granulated blast furnace slag, and the blocking agent for the granulated blast furnace slag is sodium gluconate. The aforementioned thickening agent is a cellulose-based thickening agent. The mineral-based filler is selected from the group consisting of sand, corundum, alkali-resistant glass, crushed stone, gravel, medium gravel, quartz, quartz powder, quartz sand, clay, fly ash, fumed silica, brick powder, rice husk ash, phonolite, calcined clay and metakaolin, titanium oxide and mixtures thereof. The aforementioned accelerator is calcium carbonate, and A long-term stabilized aqueous initiator composition in which the fluidity, homogeneity, and pH value of all components remain unaffected even after 6 months.

2. The long-term stabilized aqueous initiator composition according to claim 1, wherein the thickening agent is hydroxymethylcellulose or hydroxyethylcellulose.

3. The long-term stabilized aqueous initiator composition according to claim 1, wherein the long-term stabilized aqueous initiator composition has a shelf life of at least six months.

4. The long-term stabilized aqueous initiator composition according to claim 1, wherein the long-term stabilized aqueous initiator composition is in the form of a slurry or paste.

5. The long-term stabilized aqueous initiator composition according to claim 1, wherein the long-term stabilized aqueous initiator composition has a pH value greater than 10.

6. A method for preparing the long-term stable aqueous initiator composition described in claim 1, i) The process of introducing water into the mixing tank, ii) Optionally, a step of dissolving a thickener and a plasticizer under stirring and adding them, iii) Optionally, a step in which the granulated blast furnace slag and packing material are dispersed and added while increasing the stirring speed. vi) A method comprising the step of continuing stirring until the mixture is completely homogenized.

7. A method for activating the setting and hardening of curing-type aqueous alumina cement components, i) A step of adding the long-term stabilized aqueous initiator composition described in claim 1 to the curing-type aqueous phase alumina cement component, ii) A method comprising the step of mixing the long-term stabilizing aqueous initiator composition and the curing-type aqueous phase alumina cement component.

8. Use of the long-term stabilizing aqueous initiator composition according to claim 1 in a mortar system containing a curing-type aqueous alumina cement component.

9. Use of the long-term stabilizing aqueous initiator composition according to claim 1 as the first component in a two-component mortar system containing a curing-type aqueous alumina cement component.

10. The use according to claim 9, wherein the two-component mortar system has an initial setting time of at least 5 minutes.

11. Use of the long-term stabilizing aqueous initiator composition according to claim 1 for activating the setting and hardening of a curing aqueous phase alumina cement component used to chemically fix an adhesive means in a mineral substrate.

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