Cementitious material, dry-mixed mortar composition, adhesive slurry, preparation method therefor and building component

Abstract

The present invention provides a cementitious material, comprising slag and Portland cement and further comprising at least one of a formate of an alkali metal or alkaline earth metal and a hydroxide of an alkali metal or alkaline earth metal, wherein based on the weight of the slag, the content of the Portland cement is at least 3 wt.%, the content of the formate of the alkali metal or alkaline earth metal is less than or equal to 3 wt.%, and the content of the hydroxide of the alkali metal or alkaline earth metal is less than or equal to 6 wt.%. The present invention further provides a dry-mixed mortar composition using the cementitious material and an adhesive slurry formed by mixing the dry-mixed mortar composition with water. The present invention provides a novel activation system capable of activating granulated blast furnace slag powder for use as a cementitious material, so that the performance of the dry-mixed mortar composition using this cementitious material meets standard requirements.

Description

Cementitious materials, dry-mixed mortar compositions, adhesive grouts, preparation methods, and building components Technical Field

[0001] This invention relates to building materials, and more particularly to adhesive cementitious materials, dry-mixed mortar compositions comprising said cementitious materials, and adhesive slurries formed therefrom. Background Technology

[0002] Ceramic tile adhesive is a modern decorative material used for bonding ceramic tiles, facing bricks, floor tiles, and other decorative materials. Its main characteristics include high bonding strength, water resistance, freeze-thaw resistance, good aging resistance, and ease of application, making it an ideal bonding material. Considering safety, aesthetics, durability, and cost-effectiveness, maintaining excellent bonding strength at relatively low application thicknesses is an important research direction for ceramic tile adhesives.

[0003] Currently, the bonding materials in ceramic tile adhesives on the market are usually mainly cement-based.

[0004] However, the cement industry is a CO2-intensive industry. During cement production, the calcium carbonate in the main raw material, limestone, decomposes to form clinker, generating a large amount of CO2. The burning of cement clinker and the drying of raw materials also use fuels, producing considerable CO2. With increasing public awareness of the climate crisis and governments worldwide implementing strong policies and laws to reduce carbon emissions, the development and research of alternative binders to reduce CO2 emissions is an inevitable trend and a crucial task for the sustainable development of the construction industry.

[0005] Granulated blast furnace slag, commonly known as slag, is the waste residue produced during pig iron smelting in steel plants. In the blast furnace ironmaking process, in addition to iron ore and fuel (coke), appropriate amounts of limestone and dolomite are added as fluxes to lower the smelting temperature. The calcium oxide and magnesium oxide produced by their decomposition in the blast furnace, along with waste minerals from the iron ore and ash phases from the coke, melt to form a molten material mainly composed of silicates and aluminosilicates. This molten material floats on the surface of the molten iron and is periodically discharged from the slag discharge port. After rapid cooling with air or water, it forms granular particles, known as slag. Typically, slag contains over 95% glass and dicalcium silicate, as well as minerals such as anorthite and wollastonite, making its composition similar to that of cement.

[0006] Using granulated blast furnace slag powder instead of cement as a hydraulic binder can significantly reduce the carbon footprint of products. However, in practical applications, activators are needed to activate the granulated blast furnace slag powder.

[0007] Summary of the Invention

[0008] The purpose of this invention is to provide a cementitious material in which a novel activation system is used to activate granulated blast furnace slag powder, thereby replacing cement with granulated blast furnace slag powder.

[0009] Therefore, according to one aspect of the present invention, a cementitious material is provided, comprising slag and silicate cement, and further comprising at least one of an alkali metal or alkaline earth metal formate and an alkali metal or alkaline earth metal hydroxide, wherein, based on the weight of the slag, the silicate cement content is at least 3 wt.%, the alkali metal or alkaline earth metal formate content is less than or equal to 3 wt.%, and the alkali metal or alkaline earth metal hydroxide content is less than or equal to 6 wt.%.

[0010] Wherein, based on the weight of the slag, the content of the alkali metal or alkaline earth metal formate is less than or equal to 1.5 wt.%.

[0011] Based on the weight of the slag, the content of alkali metal or alkaline earth metal hydroxides is greater than or equal to 1.5 wt.% and less than or equal to 3 wt.%.

[0012] The cementing material further comprises chlorides of alkali metals or alkaline earth metals, wherein, based on the weight of the slag, the content of the chlorides of alkali metals or alkaline earth metals is at least 1.5 wt.%.

[0013] The chlorides of the alkali metals or alkaline earth metals are lithium chloride, magnesium chloride, calcium chloride, potassium chloride, or sodium chloride.

[0014] The formate of the alkali metal or alkaline earth metal is sodium formate, calcium formate, potassium formate, magnesium formate, or lithium formate.

[0015] The hydroxides of the alkali metals or alkaline earth metals are sodium hydroxide, calcium hydroxide, potassium hydroxide, magnesium hydroxide, or lithium hydroxide.

[0016] Wherein, based on the weight of the slag, the content of the silicate cement is greater than or equal to 5 wt.%.

[0017] According to another aspect of the present invention, a dry-mixed mortar composition comprises the following components:

[0018] As previously described, the cementitious material, 25-40 wt.%;

[0019] Aggregate, 55-80 wt.%;

[0020] Additives, less than or equal to 5 wt.%;

[0021] The remainder consists of fillers, based on the total weight of the dry-mixed mortar composition.

[0022] The additive is at least one of cellulose ether and redispersible latex powder.

[0023] The additives include at least one of the following: accelerator, water-retaining agent, water-reducing agent, rheology modifier, and reinforcing agent.

[0024] According to another aspect of the present invention, a method for preparing the dry-mixed mortar composition as described above includes:

[0025] Step 1: Provide the aforementioned cementitious material;

[0026] Step 2: Mix and stir the cementitious material, the aggregate, the additive and the filler in the aforementioned proportions until homogeneous.

[0027] According to another aspect of the invention, an adhesive slurry comprises the aforementioned dry-mixed mortar composition and water, wherein the weight ratio of the dry-mixed mortar composition to water is 100:15-30.

[0028] According to another aspect of the present invention, a method for preparing the aforementioned adhesive slurry includes:

[0029] Step 1: Provide the aforementioned dry-mixed mortar composition;

[0030] Step 2: Mix the dry-mixed mortar composition with water in the aforementioned proportions.

[0031] According to another aspect of the invention, a building component has a building body, wherein the surface of the building body is provided with a coating formed by the aforementioned adhesive slurry.

[0032] This invention provides a novel activation system that can activate granulated blast furnace slag powder for use as a cementing material, enabling the performance of dry-mixed mortar compositions using this cementing material to meet standard requirements. Detailed Implementation

[0033] The specific embodiments of the present invention are described below.

[0034] In this application, the term "at most" used to define the content of a component means that the content of the component is less than or equal to a specified value, and "at least" means that the content of the component is greater than or equal to a specified value. "Parts by weight" refers to weight units having the same unit and quantity; for example, 1 part by weight can be 1 gram, 1 kilogram, 10 grams, or other numerical weight units. "Fraction by weight" refers to the weight ratio of a specific component relative to a reference, expressed as a weight percentage (wt.%).

[0035] Alkali metals include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs). Alkali earth metals include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). In the industry, sodium, potassium, and lithium are commonly used alkali metals, while magnesium and calcium are commonly used alkaline earth metals.

[0036] According to one embodiment of the present invention, a cementitious material comprises slag and silicate cement, and at least one of an alkali metal or alkaline earth metal formate and an alkali metal or alkaline earth metal hydroxide.

[0037] This slag is granulated blast furnace slag powder, with a particle size commonly used in the market and conforming to the S95 grade specification stipulated in GB / T18046-2017. Granulated blast furnace slag powder can be obtained commercially.

[0038] This silicate cement is commercially available and is typically in powder form. In the embodiments described herein, general-purpose silicate cement conforming to the national standard GB175-2020 is used. Based on the weight of slag, the silicate cement content is at least 3 wt.%, preferably at least 5 wt.%.

[0039] To activate granulated blast furnace slag powder, at least one of an alkali metal or alkaline earth metal formate and an alkali metal or alkaline earth metal hydroxide is used as an activator.

[0040] The alkali metal or alkaline earth metal formate is sodium formate, calcium formate, potassium formate, magnesium formate, or lithium formate, hereinafter referred to as formate. Calcium formate is preferred.

[0041] The hydroxides of alkali metals or alkaline earth metals can be sodium hydroxide, calcium hydroxide, potassium hydroxide, magnesium hydroxide, or lithium hydroxide, hereinafter referred to as hydroxides. Calcium hydroxide is preferred. Calcium hydroxide, also known as slaked lime, is a non-toxic white powdery solid that can be used as an alkaline activator. It improves the long-term stability of products and increases their bonding strength.

[0042] In one example, formate alone can be used as the activator. In another example, hydroxide alone can be used as the activator. In a preferred example, a combination of formate and hydroxide is used as the activator.

[0043] Based on the weight of the slag, the formate content is less than or equal to 3 wt.%, preferably less than or equal to 1.5 wt.%. Based on the weight of the slag, the hydroxide content is less than or equal to 6 wt.%, preferably greater than or equal to 1.5 wt.% and less than or equal to 3 wt.%.

[0044] The cementitious material further comprises chlorides of alkali metals or alkaline earth metals. The alkali metal or alkaline earth metal chlorides are lithium chloride, magnesium chloride, calcium chloride, potassium chloride, or sodium chloride, hereinafter simply referred to as chlorides. Sodium chloride is preferred. The chloride content is at least 1.5 wt% based on the weight of the slag.

[0045] According to another embodiment of the present invention, a dry-mixed mortar composition comprises the following components:

[0046] As previously described, the cementitious material, 25-40 wt.%;

[0047] Aggregate, 55-80 wt.%;

[0048] Additives, less than or equal to 5 wt.%;

[0049] The remainder consists of fillers, based on the total weight of the dry-mixed mortar composition.

[0050] In this invention, the filler and aggregate are granules or powders, serving the functions of filling and supporting, respectively. The filler and aggregate are distinguished by particle size; for example, fine aggregate can replace filler. Commonly used fillers include limestone, but other materials can also be used. Commonly used aggregates include sand, such as natural sand, river sand, or manufactured sand, preferably ISO standard sand. Both the filler and aggregate used in this invention are commercially available. In a specific example, the aggregate is standard quartz sand, and the filler is lime powder.

[0051] Additives include one or more of accelerators, water-retaining agents, water-reducing agents, rheology modifiers, and reinforcing agents. In particular, additives may include cellulose ethers, redispersible latex powders, or combinations thereof. Accelerators, water-retaining agents, water-reducing agents, rheology modifiers, and reinforcing agents can be formulations commonly used in mortar products and are commercially available. In this application, unless otherwise specified, the amount of additives used can be determined with reference to commonly used amounts in the art.

[0052] The hydroxyl groups on cellulose ether molecules and the oxygen atoms on the ether bonds associate with water molecules to form hydrogen bonds, converting free water into bound water, thus providing excellent water retention. The interdiffusion between water molecules and cellulose ether molecular chains allows water molecules to enter the interior of the cellulose ether macromolecular chains and be strongly bound, thereby improving the water retention of the mortar. Cellulose ether can also improve the rheological properties, porous network structure, and osmotic pressure of binding mortars. Furthermore, the film-forming properties of cellulose ether can also hinder water diffusion. Cellulose ether can also prolong the setting time of mortar and delay hydration kinetics, which is beneficial for improving workability. The typical content of cellulose ether is 0.1-0.5 wt.%, based on the total weight of the dry-mixed mortar composition.

[0053] Redispersible polymer powder (RDP), also known as redispersible polymer powder, is a water-soluble redispersible powder that disperses rapidly into an emulsion upon contact with water. RDP is typically produced by spray drying of raw materials such as polymer resins, protective colloids, and anti-caking agents. RDP can adjust the alkali resistance of mortar, improve its adhesion, flexural strength, water resistance, plasticity, abrasion resistance, and workability. The polymer resins in RDP can include, but are not limited to, vinyl acetate / ethylene copolymers, styrene / butadiene copolymers, and vinyl acetate / vinyl neodecanoate copolymers. The content of RDP is typically less than or equal to 3 wt.%, based on the total weight of the dry-mixed mortar composition.

[0054] In yet another embodiment, the above-mentioned dry-mixed mortar mixture is mixed with water to form a binding slurry, wherein the weight ratio of the dry-mixed mortar composition to water is 100:15-30.

[0055] In yet another embodiment, a method for preparing the dry-mixed mortar composition as described above includes:

[0056] Step one: Provide the cementing material as described in the preceding claims;

[0057] Step 2: Mix and stir the cementitious material, the aggregate, the additive and the filler in the aforementioned proportions until homogeneous.

[0058] In yet another embodiment, a method for preparing the adhesive slurry as described above includes:

[0059] Step 1: Provide the aforementioned dry-mixed mortar composition;

[0060] Step 2: Mix the dry-mixed mortar composition with water in the aforementioned proportions.

[0061] In another embodiment, a building component has a building body, wherein the surface of the building body is provided with a coating formed by the aforementioned adhesive slurry.

[0062] Table 1 lists the components and their amounts in several examples according to embodiments of the present invention. The amount of each component is expressed in parts by weight. Dry-mixed mortar compositions and adhesive slurries are prepared according to the methods described above, based on the components and corresponding amounts of water listed in Table 1.

[0063] Table 1

[0064] According to the methods and standards specified in JC / T 547-2017 "Adhesives for Ceramic Wall and Floor Tiles", samples were prepared and their tensile bond strength was tested, with the unit being megapascals (MPa). The test results are shown in Table 2.

[0065] Table 2

[0066] As can be seen from Table 2, even without the use of redispersible latex powder, the embodiments of the present invention can still meet or approach the performance indicators specified in the national standards.

[0067] Table 3 provides examples and comparative examples of the use of chlorides. Similarly, dry-mixed mortar compositions and adhesive slurries were prepared according to the components and corresponding water amounts listed in Table 3, following the methods described above. Samples were prepared and their tensile bond strength was tested according to the methods and standards specified in JC / T 547-2017 "Ceramic Wall and Floor Tile Adhesives," in megapascals (MPa).

[0068] Table 3

[0069] Table 3 shows that the addition of sodium chloride can significantly improve the tensile bond strength and the water immersion tensile bond strength.

[0070] Although the technical details of the present invention have been described above, those skilled in the art will understand that the present invention is not limited to the specific details listed in the above embodiments, but can be varied within the scope defined by the claims.

Claims

1. A cementitious material comprising slag and silicate cement, further comprising at least one of an alkali metal or alkaline earth metal formate and an alkali metal or alkaline earth metal hydroxide, wherein, Based on the weight of the slag, the content of the silicate cement is at least 3 wt.%, the content of the alkali metal or alkaline earth metal formate is less than or equal to 3 wt.%, and the content of the alkali metal or alkaline earth metal hydroxide is less than or equal to 6 wt.%.

2. The cementitious material as described in claim 1, characterized in that, Based on the weight of the slag, the content of the alkali metal or alkaline earth metal formate is less than or equal to 1.5 wt.%.

3. The cementitious material as described in claim 1, characterized in that, Based on the weight of the slag, the content of alkali metal or alkaline earth metal hydroxides is greater than or equal to 1.5 wt.% and less than or equal to 3 wt.%.

4. The cementitious material as described in claim 1, characterized in that, It further includes chlorides of alkali metals or alkaline earth metals, wherein the content of the chlorides of alkali metals or alkaline earth metals is at least 1.5 wt.% based on the weight of the slag.

5. The cementitious material as described in claim 4, characterized in that, The chlorides of the alkali metals or alkaline earth metals are lithium chloride, magnesium chloride, calcium chloride, potassium chloride, or sodium chloride.

6. The cementitious material as described in claim 1, characterized in that, The formate of the alkali metal or alkaline earth metal is sodium formate, calcium formate, potassium formate, magnesium formate, or lithium formate.

7. The cementitious material as described in claim 1, characterized in that, The hydroxides of the alkali metals or alkaline earth metals are sodium hydroxide, calcium hydroxide, potassium hydroxide, magnesium hydroxide, or lithium hydroxide.

8. The cementitious material as described in claim 1, characterized in that, Based on the weight of the slag, the content of the silicate cement is greater than or equal to 5 wt.%.

9. A dry-mixed mortar composition comprising the following components: The cementitious material as described in any one of claims 1-8, 25-40 wt.%; Aggregate, 55-80 wt.%; Additives, less than or equal to 5 wt.%; The remainder consists of fillers, based on the total weight of the dry-mixed mortar composition.

10. The dry-mixed mortar composition as described in claim 9, characterized in that, The additive is at least one of cellulose ether and redispersible latex powder.

11. The dry-mixed mortar composition as described in claim 9, characterized in that, The additives include at least one of the following: coagulant, water-retaining agent, water-reducing agent, rheology modifier, and reinforcing agent.

12. A method for preparing the dry-mixed mortar composition according to any one of claims 9-11, comprising: Step 1: Provide the cementitious material according to any one of claims 1-8; Step 2: Mix and stir the cementitious material, the aggregate, the additive and the filler in the proportions described in claim 9 until homogeneous.

13. A binding mortar comprising the dry-mixed mortar composition as described in any one of claims 9-11 and water, wherein the weight ratio of the dry-mixed mortar composition to water is 100:15-30.

14. A method for preparing the adhesive slurry of claim 13, comprising: Step 1: Provide the dry-mixed mortar composition according to claims 9-11; Step 2: Mix the dry-mixed mortar composition with water in the proportions described in claim 13.

15. A building component having a building body, wherein the surface of the building body is provided with a coating formed by the adhesive slurry of claim 13.

Images