Two-component mortar system based on aluminous cement and granulated blast furnace slag and its use

Abstract

The present invention relates to a two-component mortar system for the chemical fixation of anchoring means in mineral substrates, comprising a cured aqueous phase aluminous cement component A and an initiator component B in the aqueous phase for starting the curing process, component A further comprising at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid and phosphonic acid, and water, and component B comprising blocked granulated blast furnace slag, water and optionally at least one mineral filler.Furthermore, the present invention relates to a ready-to-use two-component system for the chemical fixation of anchoring means, preferably of metal elements, in mineral substrates such as brickwork, concrete, permeable concrete or structures made of natural stone, as well as to its use for the chemical fixation of anchoring means.

Description

[Technical Field]

[0001] The present invention relates to a two-component mortar system for the chemical fixation of anchoring means in mineral matrices, comprising a cured aqueous phase alumina cement component A and an initiator component B in the aqueous phase for starting the curing process, wherein component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked granulated blast furnace slag, water, and optionally at least one mineral filler. Furthermore, the present invention relates to a ready-to-use two-component mortar system for the chemical fixation of anchoring means, preferably metal elements, in mineral matrices such as brickwork, concrete, permeable concrete, or structures made of natural stone, as well as to its use for the chemical fixation of anchoring means. [Background technology]

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

[0003] To overcome these drawbacks, primarily 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 exhibits high levels of mechanical performance over time. Alumina cement is also resistant to bases, achieves maximum strength more quickly than Portland cement, and can withstand sulfate solutions. Therefore, alumina cement systems are preferred in the field of chemical fixation.

[0004] Furthermore, calcium aluminate slurries are known to provide high fire resistance at anchorage points. However, compared to resin-based anchoring mortars, the setting of such systems is considerably slower, which often requires longer waiting times on site and interrupts the workflow. This is particularly important for anchoring applications where immediate loading is crucial. In addition, calcium aluminate-based mortars contain the metastable hydrate phase CAH 10 and undergoes conversion resulting in a decrease in performance over time due to transformation of C2AH8 to the stable hydrate C3AH6.

[0005] EP 2162410 describes a ready-to-use two-component system comprising Part A, based on an aqueous phase alumina cement retarded by boric acid or its salts, and Part B, for initiating the curing process. The initiator in Part B is made solely of lithium salts. EP 0081385 also discloses a two-component system comprising an aqueous high-alumina cement composition with inhibited set and a reactivator composition containing lithium salts. EP 2794510 describes stabilized aqueous suspensions containing alumina cement and / or calcium sulfoaluminate cement, which are inhibited by phosphorus-containing compounds and can be stored for a sufficient period of time even at high temperatures. Such stabilized aqueous suspensions can serve as a base for surface coatings.

[0006] However, these aqueous alumina cement suspensions retarded by boric acid or its salts are often not very stable for a sufficient period of time for storage before use. Moreover, boric acid is highly toxic and ecotoxic. Furthermore, these state-of-the-art systems require high water-to-cement ratios and are characterized by their undesirable conversion, which reduces performance over time.

[0007] German Patent No. 2311239 describes an adjuvant composition for improving the setting and hardening properties of alumina cements and mortars, comprising lithia, a water-soluble lithium salt, and a hydroxylated organic acid or its salt or ester. The fluid may be incorporated directly into the alumina cement or into mortar and concrete during their manufacture, or added to the mixing water during application. However, a drawback of this system is that the cement composition and activator composition cannot be stored long enough to be ready for use and must therefore be freshly prepared before use depending on the desired setting and hardening time, resulting in more procedural steps before application. Furthermore, the lithium-based activator component is expensive, its extraction is problematic from humanitarian, economic, and political perspectives, and it has a high carbon footprint.

[0008] Therefore, there is a need for a ready-to-use multi-component system, preferably a two-component system, that is superior to the systems of the prior art in terms of environmental aspects, health and safety, handling, storage time, sustainability, and a good balance between setting and hardening of the mortar. Furthermore, it is of interest to provide a system that can be used to chemically fix anchoring means in mineral substrates without adversely affecting the handling, properties, and mechanical performance of the chemical anchoring system, as well as to provide a system that uses a lower water-to-cement ratio and conversion, which increases performance over time. Finally, there is a need for a system with a low carbon dioxide footprint.

[0009] In view of the above, it is an object of the present invention to provide a multi-component system, in particular a two-component mortar system, which overcomes the drawbacks of the systems of the prior art, in particular a two-component mortar system which is ready to use, easy to handle, environmentally friendly, can be stored stably for a certain period of time before use, exhibits a good balance between setting and hardening, still has good mechanical performance with regard to chemical fixing of the anchoring means even under the influence of elevated temperatures, and is further characterized by the ability to reduce carbon dioxide emissions, water-to-cement ratio and conversion.

[0010] It is further an object of the present invention to provide a two-component mortar system that can be used for the chemical fixation of anchoring means, preferably metal elements, in mineral substrates such as brickwork, concrete, permeable concrete or structures made of natural stone, as well as to provide a method for fixing said anchoring means.

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

[0012] Summary of the Invention In one aspect, the present invention provides a ready-to-use two-component mortar system comprising a cured aqueous phase alumina cement component A and an initiator component B in the aqueous phase for starting the curing process, wherein component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked granulated blast furnace slag, water, and optionally at least one mineral filler. In particular, component B comprises granulated blast furnace slag and a blocking agent selected from the group consisting of gluconic acid, glycolic acid, phosphonic acid, salts and esters thereof, glucose, and mixtures thereof.

[0013] In another aspect, the present invention provides a two-component mortar system to be used for the chemical fixation of anchoring means, preferably metal elements, in mineral substrates such as brickwork, concrete, pervious concrete or structures made of natural stone, and in another aspect a method for fixing said anchoring means and a method for fixing said anchoring means. DETAILED DESCRIPTION OF THE INVENTION

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

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

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

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

[0018] The term "binder" or "binder component" in the context of the present invention refers to the calcium-aluminate based cementitious component and other additional optional components such as, for example, fillers. In particular, the term "main binder component" refers to component A.

[0019] Surprisingly, the inventors have found that the two-component mortar system according to the present invention is an easy-to-handle, ready-to-use system for chemically fixing anchoring means in mineral substrates. In particular, it has been found that systems based on aqueous slurries containing a blocked alumina component as the primary binder component and blocked ground-granulated blast-furnace slag (GGBFS) in an aqueous slurry exhibiting an alkaline pH as the secondary binder component can utilize lower water-to-cement ratios compared to state-of-the-art two-component injection mortars containing a filler-based activator component. In addition, it has been found that the long-term strength loss due to conversion characteristic of calcium aluminate cements can be mitigated by blending these two cements to produce a stable stratlingite hydrate phase, since the slag provides a source of reactive silicate.

[0020] While typical calcium aluminate-based binders rely on synthetic or mined carbonate sources to mitigate strength loss due to conversion phenomena, granulated blast furnace slag is a waste product from steel production and therefore inexpensive and has a low carbon footprint when reused as a binder. Blocking granulated blast furnace slag with a sugar, such as gluconate, in water achieves an alkaline pH that can be used to activate the blocked calcium aluminate cement component. Thus, a separate activator, such as sodium hydroxide or lithium hydroxide, is not required. The alkaline pH generated from the hydration of calcium aluminate cement subsequently activates the granulated blast furnace slag.

[0021] Furthermore, it has been found that the two-component mortar system of the present invention does not contain any harmful substances while maintaining the standards for chemical bonding applications, and therefore also involves a reduction in carbon dioxide emissions and labeling. In addition, it has been found that the use of granulated blast furnace slag in particular is more sustainable compared to the use of common Portland cement, and also has a lower carbon dioxide emissions than synthetic resins.

[0022] The present invention relates to a two-component mortar system for chemically fixing anchoring means in mineral matrices, comprising a cured aqueous phase aluminous cement component A and an initiator component B in the aqueous phase for initiating the curing process. In particular, component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, and water, and component B comprises blocked granulated blast furnace slag, water, and optionally at least one mineral filler.

[0023] Component A according to the invention is based on aqueous calcium aluminate cement (CAC) or aqueous calcium sulfoaluminate cement (CAS). Calcium aluminate cements that can be used in the invention are characterized by rapid setting and hardening, rapid drying and shrinkage compensation when mixed with calcium sulfate, and excellent corrosion and shrinkage resistance. An example of such calcium aluminate cement suitable for use in the invention is Ternal® White (Kerneos, France).

[0024] When component A contains a mixture of calcium aluminate cement (CAC) and calcium sulfate (CaSO4), rapid ettringite formation occurs during hydration. In concrete chemistry, the reaction between calcium aluminate and calcium sulfate forms hexacalcium aluminate trisulfate hydrate, represented by the general formula (CaO)6(Al2O3)(SO3)3·32H2O or (CaO)3(Al2O3)(CaSO4)3·32H2O, resulting in rapid setting and hardening, as well as shrinkage compensation or even expansion. Shrinkage compensation can be achieved by moderately increasing the sulfate content.

[0025] Component A of the present invention comprises at least about 40 wt. %, preferably at least about 50 wt. %, more preferably at least about 60 wt. %, and most preferably at least about 70 wt. %, about 40 wt. % to about 95 wt. %, preferably about 50 wt. % to about 90 wt. %, more preferably about 60 wt. % to about 85 wt. %, and most preferably about 70 wt. % to about 80 wt. % of calcium aluminate cement, based on the total weight of Component A.

[0026] According to an alternative embodiment of the present invention, Component A comprises at least about 20 wt%, preferably at least about 30 wt%, more preferably at least about 40 wt%, and most preferably at least about 50 wt%, or about 20 wt% to about 80 wt%, preferably about 30 wt% to about 70 wt%, more preferably about 35 wt% to about 60 wt%, and most preferably about 40 wt% to about 55 wt% aluminous cement, based on the total weight of Component A, and at least about 5 wt%, preferably at least about 10 wt%, more preferably at least about 15 wt%, most preferably at least about 20 wt%, about 1 wt% to about 50 wt%, preferably about 5 wt% to about 40 wt%, more preferably about 10 wt% to about 30 wt%, and most preferably about 15 wt% to about 25 wt% calcium sulfate, preferably calcium sulfate hemihydrate, based on the total weight of Component A. In a preferred alternative embodiment of the two-component mortar system of the present invention, the CaSO4 / CAC ratio in Component A should be 35:65 or less.

[0027] The blocking agent contained in Component A according to the present invention is selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, preferably phosphoric acid or metaphosphoric acid, and most preferably phosphoric acid, especially an 85% aqueous solution of phosphoric acid. Component A contains at least about 0.1 wt. %, preferably at least about 0.3 wt. %, more preferably at least about 0.4 wt. %, most preferably at least about 0.5 wt. %, about 0.1 wt. % to about 20 wt. %, preferably about 0.1 wt. % to about 15 wt. %, more preferably about 0.1 wt. % to about 10 wt. %, most preferably about 0.3 wt. % to about 10 wt. % of the blocking agent, based on the total weight of Component A. In a preferred embodiment, Component A contains about 0.3 wt. % to about 10 wt. % of an 85% aqueous solution of phosphoric acid, based on the total weight of Component A.

[0028] In advantageous embodiments, component A further comprises the following properties, alone or in combination:

[0029] Component A may additionally comprise a plasticizer. The plasticizer may be selected from the group consisting of low molecular weight (LMW) polyacrylic acid polymers, fluidizers from the families of polyphosphonate and polycarbonate polyox, and Ethacryl fluidizers from the polycarboxylate ether group, and mixtures thereof, such as Ethacryl™ G (Coatex, Arkema Group, France), Acumer™ 1051 (Rohm and Haas, UK), or Sika™ ViscoCrete™-20 HE (Sika, Germany). Suitable plasticizers are commercially available products. Component A may contain at least about 0.2 wt %, preferably at least about 0.3 wt %, more preferably at least about 0.4 wt %, and most preferably at least about 0.5 wt %, of the plasticizer, based on the total weight of Component A, from about 0.2 wt % to about 20 wt %, preferably from about 0.3 wt % to about 15 wt %, more preferably from about 0.4 wt % to about 10 wt %, and most preferably from about 0.5 wt % to about 5 wt %.

[0030] Component A may additionally contain a thickener. Thickeners that can be used in the present invention may be selected from the group consisting of organic products such as xanthan gum, welan gum, or DIUTAN® gum (CP Kelko, USA), mineral products such as starch-derived ethers, guar-derived ethers, polyacrylamides, carrageenans, agar, and clays, and mixtures thereof. Suitable thickeners are commercially available products. Component A contains at least about 0.01% by weight, preferably at least about 0.1% by weight, more preferably at least about 0.2% by weight, and most preferably at least about 0.3% by weight, from about 0.01% to about 10% by weight, preferably from about 0.1% to about 5% by weight, more preferably from about 0.2% to about 1% by weight, and most preferably from about 0.3% to about 0.7% by weight of the thickener, based on the total weight of Component A.

[0031] Component A may further comprise an antibacterial agent or biocide. The antibacterial agent or biocide that can be used in the present invention may be selected from the group consisting of compounds of the isothiazolinone family, such as methylisothiazolinone (MIT), octylisothiazolinone (OIT), and benzisothiazolinone (BIT), and mixtures thereof. Suitable antibacterial agents or biocides are commercially available products. Ecocide K35R (Progiven, France) and Nuosept OB 03 (Ashland, The Netherlands) are mentioned as examples. Component A comprises at least about 0.001 wt. %, preferably at least about 0.005 wt. %, more preferably at least about 0.01 wt. %, and most preferably at least about 0.015 wt. %, from about 0.001 wt. % to about 1.5 wt. %, preferably from about 0.005 wt. % to about 0.1 wt. %, more preferably from about 0.01 wt. % to about 0.075 wt. %, and most preferably from about 0.015 wt. % to about 0.03 wt. % of the antimicrobial or biocide, based on the total weight of Component A. In a preferred embodiment, Component A comprises from about 0.015 wt. % to about 0.03 wt. % Nuosept OB 03, based on the total weight of Component A.

[0032] Component A may further comprise at least one mineral filler. Mineral fillers that can be used in the present invention include limestone fillers, such as calcite, sand, corundum, dolomite, alkali-resistant glass, crushed stone, gravel, gravel, quartz, quartz flour, quartz sand, clay, fly ash, fumed silica, brick powder, rice peel ash, phonolite, calcined clay, and metakaolin, carbonate compounds, pigments, titanium dioxide, lightweight fillers, or mixtures thereof. Suitable fillers are commercially available products. Component A may comprise at least about 1 wt. %, preferably at least about 2 wt. %, more preferably at least about 5 wt. %, and most preferably at least about 8 wt. % of the at least one filler, based on the total weight of Component A.

[0033] The water content of component A is at least about 1% by weight, preferably at least about 5% by weight, more preferably at least about 10% by weight, and most preferably at least about 20% by weight, and is about 1% to about 50% by weight, preferably about 5% to about 40% by weight, more preferably about 10% to about 30% by weight, and most preferably about 15% to about 25% by weight, based on the total weight of component A.

[0034] The presence of plasticizers, thickeners, antimicrobial agents, biocides, or fillers does not change the overall inorganic character of cementitious component A.

[0035] Component A, which comprises a calcium aluminate or calcium sulfoaluminate cement, is present in the aqueous phase, preferably in the form of a slurry or paste.

[0036] Initiator component B of the present invention comprises blocked granulated blast furnace slag, water, and optionally at least one mineral filler.

[0037] Granulated blast furnace slag preferably contains 30-45% calcium oxide (CaO), 30-45% silicon dioxide (SiO), 1-15% aluminum oxide (AlO), 4-17% magnesium oxide (MgO), and 0.5-1% sulfur (S). Further characteristic contents of granulated blast furnace slag are iron oxide (FeO), sodium oxide (NaO), potassium oxide (KO), chloride, sulfur trioxide (SO), and manganese oxide (MnO), which preferably account for less than 5% of the granulated blast furnace slag.

[0038] Component B of the present invention contains at least about 5% 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 granulated blast furnace slag in an amount of about 5% to about 80% by weight, preferably about 10% to about 70% by weight, more preferably about 20% to about 60% by weight, and most preferably about 30% to about 55% by weight, based on the total weight of Component B.

[0039] The blocked granulated blast furnace slag of Component B comprises granulated blast furnace slag and a blocking agent. The blocking agent for the granulated blast furnace slag is selected from the group consisting of gluconic acid, glycolic acid, phosphonic acid, their salts and esters, glucose, and mixtures thereof. Preferably, the blocking agent is a gluconate, more preferably sodium gluconate.

[0040] Component B contains at least about 0.01 wt %, preferably at least about 0.05 wt %, more preferably at least about 0.1 wt %, and most preferably at least about 1.0 wt %, of the blocking agent, based on the total weight of Component B. In a most preferred embodiment, Component B contains about 0.2 to about 0.4 wt % sodium gluconate.

[0041] Component B may optionally contain at least one mineral filler. Mineral fillers that can be used in the present invention include limestone fillers, such as calcite, sand, corundum, dolomite, alkali-resistant glass, crushed stone, gravel, gravel, quartz, quartz flour, quartz sand, clay, fly ash, fumed silica, brick powder, rice husk ash, phonolite, calcined clay, and metakaolin, carbonate compounds, pigments, titanium dioxide, lightweight fillers, or mixtures thereof. Suitable fillers are commercially available products. Component B may contain at least about 1 wt. %, preferably at least about 10 wt. %, more preferably at least about 20 wt. %, and most preferably at least about 30 wt. % of the at least one filler, based on the total weight of Component B. The at least one mineral filler contained in Component B according to the present invention is preferably a mixture of mineral fillers. The at least one mineral filler is selected to obtain a particle size complementary to the particle size of the aluminous cement and the granulated blast furnace slag.

[0042] In advantageous embodiments, component B further comprises the following properties, alone or in combination:

[0043] 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. Examples that may be mentioned include 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 hydroxy ethyl cellulose (HMHEC), sodium carboxymethyl cellulose (SCMC), sodium carboxymethyl 2-hydroxyethyl cellulose, 2-hydroxypropyl methylcellulose, 2-hydroxyethyl methylcellulose, 2-hydroxybutyl methylcellulose, 2-hydroxyethyl ethyl cellulose, 2-hydroxypropyl cellulose, attapulgite clay, and mixtures thereof. Suitable thickeners are commercially available products such as Optigel WX (BYK-Chemie GmbH, Germany), Rheolate 1 (Elementis GmbH, Germany), and Cellosize™, Acrysol ASE-60 (The Dow Chemical Company).Component B comprises at least about 0.01 wt. %, preferably at least about 0.05 wt. %, more preferably at least about 0.1 wt. %, and most preferably at least about 0.3 wt. %, of the thickener, based on the total weight of Component B, from about 0.01 wt. % to about 15 wt. %, preferably from about 0.05 wt. % to about 10 wt. %, more preferably from about 0.1 wt. % to about 5 wt. %, and most preferably from about 0.1 wt. % to about 1 wt. %.

[0044] In a preferred embodiment, Component B may comprise a cellulosic thickener such as hydroxymethyl cellulose (HMC) or hydroxyethyl cellulose (HEC).

[0045] Component B may additionally comprise a plasticizer. The plasticizer may be selected from the group consisting of low molecular weight (LMW) polyacrylic acid polymers, fluidizers from the families of polyphosphonate and polycarbonate polyox, and Ethacryl fluidizers 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 B may contain at least about 0.2 wt %, preferably at least about 0.3 wt %, more preferably at least about 0.4 wt %, and most preferably at least about 0.5 wt %, about 0.2 wt % to about 20 wt %, preferably about 0.3 wt % to about 15 wt %, more preferably about 0.4 wt % to about 10 wt %, and most preferably about 0.5 wt % to about 5 wt % of the plasticizer, based on the total weight of Component B.

[0046] The water content of component B is at least about 1% by weight, preferably at least about 5% by weight, more preferably at least about 10% by weight, and most preferably at least about 20% by weight, and is about 1% to about 50% by weight, preferably about 5% to about 40% by weight, more preferably about 10% to about 30% by weight, and most preferably about 15% to about 25% by weight, based on the total weight of component B.

[0047] The presence of plasticizers and thickeners does not change the overall inorganic character of Component B.

[0048] Component B, which comprises blocked granulated blast furnace slag, is present in the aqueous phase, preferably in the form of a slurry or paste.

[0049] Furthermore, Component A and / or Component B may contain an accelerator component. The accelerator component is composed 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, and most preferably lithium sulfate or lithium sulfate monohydrate. Component A and / or B comprises at least about 0.01 wt. %, preferably at least about 0.05 wt. %, more preferably at least about 0.1 wt. %, and most preferably at least about 1.0 wt. %, and from about 0.01 wt. % to about 25 wt. %, preferably from about 0.05 wt. % to about 20 wt. %, more preferably from about 0.1 wt. % to about 15 wt. %, and most preferably from about 1.0 wt. % to about 10 wt. % of the accelerator, based on the total weight of Component A or B, respectively.

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

[0051] In the most preferred embodiment, component A comprises or consists of the following components: 70-80% by weight of calcium aluminate cement, 0.5 to 1.5% by weight of phosphoric acid, 0.5 to 1.5 wt. % of a thickener; 0.5 to 1.5 wt. % of a plasticizer; 0.001 to 0.05 wt. % of an antimicrobial or biocide; 15 to 25% by weight of water, Optionally, 0.01% to 5% by weight of lithium sulfate or lithium sulfate monohydrate, and Optionally, 5-20 wt.% mineral filler.

[0052] In the most preferred embodiment, component B comprises or consists of the following components: 45% to 55% by weight of granulated blast furnace slag; 0.1 to 0.5% by weight of sodium gluconate, 10 to 30 wt. % of at least one mineral filler; 0.01% to 0.5% by weight of a thickening agent; 0.5 to 1.5 wt. % of a plasticizer; 15% to 30% by weight of water, and Optionally, 0.01% to 5% by weight of lithium sulfate or lithium sulfate monohydrate.

[0053] Component A of the present invention can be prepared as follows: A phosphorus-containing blocking agent is mixed with water so that the pH of the resulting mixture is about 2; a plasticizer is added and the mixture is homogenized; alumina cement, optionally calcium sulfate, and optionally a mineral filler are premixed and gradually added to the mixture with increasing stirring speed so that the pH of the resulting mixture is about 4; and finally, a thickener and an antimicrobial / biocide, and optionally an accelerator component, are added and mixed until the mixture is completely homogenous.

[0054] Component B of the present invention can be prepared as follows: the plasticizer and thickener are mixed with water, followed by gradually adding granulated blast furnace slag and filler at increasing stirring speed until the mixture is homogeneous. Finally, optional accelerator components may be added until the mixture is completely homogeneous.

[0055] Components A and B are present in the aqueous phase, preferably in the form of a slurry or paste. In particular, components A and B have a pasty to fluid appearance according to their respective compositions. In a preferred embodiment, components A and B are in the form of a paste, thereby preventing sagging when mixing the two components.

[0056] 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.

[0057] The present two-component system is mineral in nature and is not affected by the presence of additional thickeners or other agents.

[0058] The shelf life of the present two-component system depends on the individual shelf life of each of the components, and in particular, Components A and B have a shelf life of at least 6 months at ambient temperature to protect the system from storage and delivery delays. Most preferably, Components A and B are individually stable for at least 6 months. Components A and B were stored at 20°C in sealed containers to prevent water evaporation and were examined for flowability, homogeneity, whether sedimentation occurred, and any changes in pH value after several time intervals. The properties of all components remained unaffected after 6 months, so the shelf life is at least 6 months at 20°C.

[0059] After mixing of the two components A and B, it is preferred that the two-component mortar system has an initial setting time of at least 5 minutes, preferably at least 10 minutes, more preferably at least 15 minutes, most preferably at least 20 minutes, in particular in the range of about 5 to 25 minutes, preferably in the range of about 10 to 20 minutes.

[0060] In multi-component mortar systems, especially two-component mortar systems, the volume ratio of cementitious component A to initiator component B is 1:1 to 7:1, preferably 3:1. In an alternative embodiment, the volume ratio of cementitious component A to initiator component B is 1:3 to 1:2.

[0061] After being produced separately, components A and B are introduced into separate containers, from which they are discharged by a mechanical device and guided through a mixing device. The two-component mortar system of the present invention is preferably a ready-to-use system, in which components A and B are placed 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-part capsule, preferably a two-chamber cartridge or a two-part capsule. The multi-chamber system preferably includes two or more foil bags for separating the cured 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 a borehole. It is also possible to assemble a set of multiple chamber cartridges or pails or buckets.

[0062] The settable alumina cement composition leaving the static mixer is optionally required to fix the anchoring means and is inserted directly into the borehole where the mineral matrix is ​​first introduced during the chemical fixation of the anchoring means, after which the construction element to be fixed, e.g., anchor rod, is inserted and adjusted, after which the mortar composition sets and hardens. In particular, the two-component system of the present invention is considered as a chemical anchor for fixing anchoring means, in particular metal elements.

[0063] The two-component mortar system of the present invention can be used for the chemical fixation of anchoring means, preferably metal elements such as anchor rods, especially threaded rods, bolts, steel reinforcements, in mineral substrates such as brickwork, concrete, permeable concrete or structures made of natural stone. In particular, the two-component mortar system of the present invention can be used for the chemical fixation of anchoring means, such as metal elements in boreholes. This can be used for fixing purposes that involve an increase in load capacity at temperatures above room temperature or at elevated temperatures, for example above 80°C, and / or an increase in bond strength stress in the cured state.

[0064] In particular, the two-component mortar system of the present invention is used in a method for chemically fixing anchoring means in a mineral substrate, the method comprising the steps of introducing a borehole into the mineral substrate, mixing component A with component B to obtain a settable alumina cement composition, inserting this alumina cement composition directly into the borehole, inserting and adjusting the construction element to be fixed, and allowing the alumina cement composition to harden and set.

[0065] Furthermore, the two-component mortar system of the present invention may be used for coating or for attaching fibers, scrims, fabrics or composites, in particular high-modulus fibers, preferably carbon fibers, in particular for the reinforcement of building structures, for example walls or ceilings or floors, or even for placing components, such as plates or blocks made of stone, glass or plastic, on building or structural elements.

[0066] The following examples illustrate the present invention without, however, limiting it thereby. [Example]

[0067] 1. Preparation of Components A and B First, cementitious component A and initiator component B are prepared by mixing the components specified in Tables 1 and 2, respectively. The proportions given are expressed in weight percent.

[0068] Specifically, 19.48 grams of deionized water, 0.75 grams of 85% phosphoric acid (blocking agent), 0.6 grams of Ethacryl G (superplasticizer), and 0.02 grams of Nuosept® (biocide) were homogenized at room temperature, and while stirring with a dissolver, calcium aluminate cement (78.50 grams, pure Ternal White®) was added in small portions to finally obtain a smooth, liquid, paste-like slurry of blocked cement in water with a pH of less than 7. After 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.

[0069] [Table 1]

[0070] An exemplary preparation of Component B is as follows: In 21.00 grams of deionized water, 1.0 gram of Ecodis® P50 (plasticizer), 0.1 gram of Cellosize™ QP-100MH (thickener), and 0.22 gram of sodium gluconate were dissolved. While stirring in a dissolver, 50 grams of granulated blast furnace slag, 17 grams of sand, and 10.68 grams of Betocarb UF were added with vigorous stirring to ultimately obtain a smooth, liquid, paste-like slurry of solids in water with a pH greater than 11.

[0071] [Table 2]

[0072] 2. Mechanical Performance Determination After preparation, binder component A and each B component were filled into separate chambers of a two-part plastic hard cartridge in a specified ratio of component A:B = 3:1. The hard cartridge was placed in a dispenser, a static mixer was attached, and the mortar was poured into a steel sleeve, into which a threaded rod (M8) was inserted. The steel sleeve was 28 mm deep and 10 mm in diameter. The pull-out strength was measured after a certain curing time to determine the improvement in performance over the curing time of the mortar. The ultimate failure load was calculated as the bond strength and is reported in N / mm in Table 3. 2 Shown in units.

[0073] [Table 3]

[0074] Table 3 shows that when the blocked slag slurry is mixed with the blocked aluminate slurry, good load values ​​can be achieved already within 24 hours of curing. The preferred ratio is A:B = 1:3-6:1, more preferably 1:1-5:1, even more preferably 2:1-4:1, and most preferably A:B = 3:1.

[0075] As shown above, the two-component mortar system of the present invention offers a curing rate and mechanical strength comparable to systems known in the art, but its essentially mineral composition makes it much less toxic than known systems of the prior art, much less polluting to the environment and allowing for cost-effective production.

[0076] Furthermore, it was shown that aqueous slurry-based systems containing blocked alumina as the primary binder component and blocked granulated blast furnace slag (GGBFS) in an alkaline pH aqueous slurry as the secondary binder component can utilize lower water-to-cement ratios compared to state-of-the-art two-component pourable mortars containing filler-based activator components. Additionally, it was shown that the long-term strength loss due to conversion characteristic of calcium aluminate cements can be mitigated by blending these two cements to produce a stable stratlingite hydrate phase.

[0077] Advantageously, it has been demonstrated that granulated blast furnace slag, which is a waste product from steel production and therefore a cheap alternative with a low carbon dioxide footprint when reused as a binder, can be used in inorganic fixation systems.

[0078] Furthermore, the two-component mortar system of the present invention has been shown to contain no harmful substances while maintaining the standards for chemical bonding applications, thus also including reduced carbon dioxide emissions and labeling. In addition, the use of granulated blast furnace slag in particular has been shown to be more sustainable compared to the use of common Portland cement, and also to have a lower carbon dioxide emissions than synthetic resins.

Claims

1. A two-component mortar system comprising a cured aqueous phase alumina cement component A and an initiator component B in the aqueous phase for initiating the curing process, wherein component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, water, and an accelerator; and component B comprises: 45% to 55% by weight of granulated blast furnace slag; 0.1 to 0.5% by weight of sodium gluconate, 10 to 30% by weight of at least one mineral filler, 0.01% to 0.5% by weight of a thickening agent; 0.5 to 1.5 wt. % of a plasticizer; A two-component mortar system containing 15% to 30% by weight of water.

2. 2. The two-component mortar system according to claim 1, wherein component B comprises as thickener a cellulose-based thickener such as hydroxymethyl cellulose or hydroxyethyl cellulose.

3. 2. The two-component mortar system of claim 1, wherein the at least one mineral filler in component B is limestone filler, sand, corundum, dolomite, alkali-resistant glass, crushed stone, gravel, pebbles, quartz, quartz flour, quartz sand, clay, fly ash, fumed silica, brick dust, rice husk ash, phonolite, calcined clay and metakaolin, carbonate compounds, pigments, titanium dioxide, lightweight fillers, or mixtures thereof.

4. 2. The two-component mortar system according to claim 1, wherein component A and component B have a shelf life of at least six months.

5. 2. The two-component mortar system according to claim 1, wherein component A and component B are in the form of a slurry or paste.

6. The two-component mortar system of claim 1 , wherein the two-component mortar system has an initial setting time of at least 5 minutes.

7. 2. The two-component mortar system according to claim 1, wherein the pH value of component B is greater than 10.

8. 10. Use of the two-component mortar system according to claim 1 for chemically fixing anchoring means in a mineral substrate.

9. 9. Use according to claim 8, wherein the fastening means is a metal element, which is an anchor rod, a threaded anchor rod, a bolt or a steel reinforcement.

10. 10. Use according to claim 8 or 9, wherein the mineral substrate is a structure made of brickwork, concrete, pervious concrete or natural stone.

11. 1. A method for chemically fixing an anchoring means in a mineral substrate, comprising a two-component mortar system comprising a cured aqueous phase alumina cement component A and an initiator component B in the aqueous phase for starting the curing process, wherein component A further comprises at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acid, water, and an accelerator; and component B comprises: 45% to 55% by weight of granulated blast furnace slag; 0.1 to 0.5% by weight of sodium gluconate, 10 to 30% by weight of at least one mineral filler, 0.01% to 0.5% by weight of a thickening agent; 0.5 to 1.5 wt. % of a plasticizer; 15% to 30% by weight of water a two-component mortar system is used, the method comprising: - introducing a borehole into the mineral matrix; - mixing component A with component B to obtain a settable alumina cement composition; - inserting the alumina cement composition directly into the borehole; - inserting and adjusting the construction element to be fixed; - allowing the alumina cement composition to harden and set.

Images