Water-resistant and early-strength gypsum cementing material as well as preparation method and application thereof

Abstract

The invention discloses a water-resistant and early-strength gypsum cementing material as well as a preparation method and application thereof. The water-resistant and early-strength gypsum cementing material comprises gypsum powder, a modified high-aluminum active mineral substance, an inorganic mineral exciting agent, a biological water repellent, an inorganic phase reaction promoting substance and a setting time regulator, wherein the specific surface area of the power plant modified high-alumina fly ash is greater than 800 m < 2 > / kg, and alumina is greater than or equal to 70%; wherein the specific surface area of the modified blast furnace slag powder is greater than 800 m < 2 > / kg, and the 28d activity index is greater than or equal to 95; the biological water repellent is spore powder of a wild lycopodium clavatum plant, also known as lycopodium powder. When the water-resistant and early-strength gypsum cementing material is prepared into a gypsum product, the water-resistant and early-strength gypsum cementing material shows excellent water resistance, the softening coefficient is obviously improved, and the early strength is also obviously enhanced. The material has the main characteristics of excellent water resistance and high early strength, so that the material has potential advantages in various application scenes and can be simultaneously applied to indoor dry and wet areas.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a water-resistant, early-strength gypsum cementitious material, its preparation method, and its application. Background Technology

[0002] Gypsum cementitious materials, as one of the three major cementitious materials, have a long history and are a green, low-carbon, and environmentally friendly building material. Their production process consumes only one-quarter the energy of cement. Research on gypsum cementitious materials began in China in the 1980s. After years of technological accumulation, a deep understanding of their applications has been achieved. For example, gypsum cementitious materials are widely used in board products (such as paper-faced gypsum board, gypsum strips, gypsum blocks, etc.), plastering products (such as plastering gypsum, gypsum putty, etc.), and adhesive products (such as bonding gypsum, jointing gypsum, gypsum tile adhesive, etc.), finding their place in multiple industries.

[0003] However, the dihydrate gypsum formed by the reaction of hemihydrate gypsum powder with water is a slightly soluble substance. Therefore, gypsum products prepared using gypsum cementitious materials typically have poor water resistance, a low softening coefficient, and significant strength loss after immersion in water. These characteristics limit the application of gypsum cementitious materials in humid environments, thus affecting the expansion of their application range. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of poor water resistance and narrow application range of the aforementioned gypsum cementitious materials, and to provide a water-resistant, early-strength gypsum cementitious material, its preparation method, and its applications. The water-resistant, early-strength gypsum cementitious material prepared by this invention exhibits excellent water resistance when formulated into gypsum products, significantly improves the softening coefficient, and also shows a marked enhancement in early strength. Its main characteristics include excellent water resistance and high early strength, which give this material potential advantages in various application scenarios, especially its ability to be used simultaneously in both dry and wet indoor areas.

[0005] To solve the above problems, the present invention is achieved through the following technical solution:

[0006] The first objective of this invention is:

[0007] A water-resistant, early-strength gypsum cementitious material is provided, comprising the following components in parts by weight:

[0008] 30.0-85.0 parts of gypsum powder, 10.0-25.0 parts of modified high-alumina active minerals, 0.1-2 parts of inorganic mineral activator, 0.1-1 parts of biological hydrophobic agent, 2-8 parts of inorganic phase reaction promoter, 0.2-1 parts of setting time regulator, and 25.0-55.0 parts of quartz sand;

[0009] The modified high-alumina active mineral is a mixture of power plant modified high-alumina fly ash and modified blast furnace slag powder;

[0010] The modified high-alumina fly ash for power plants is a high-alumina fly ash with a specific surface area > 800 m² / kg and an alumina content ≥ 70%.

[0011] The modified blast furnace slag powder is a blast furnace slag powder with a specific surface area > 800 m² / kg and an activity index ≥ 95 after 28 days.

[0012] The inorganic mineral activator is one or a mixture of several of aluminum sulfate, potassium sulfate, sodium sulfate, potassium aluminum sulfate, sodium silicate, and potassium silicate;

[0013] The aforementioned biological hydrophobic agent is the spore powder of the wild Lycopodium clavatum plant, also known as Lycopodium powder;

[0014] The inorganic phase reaction promoting substance is one or a mixture of several of the following: calcium hydroxide, quicklime, silicate cement, sulfate cement, sulfoaluminate cement, and high-alumina cement.

[0015] The setting time regulator is one or a mixture of two of the following: organic acid retarder, phosphate retarder, boric acid, amino acid retarder, and protein retarder.

[0016] Further optimization of the water-resistant, early-strength gypsum cementitious material of the present invention is as follows:

[0017] The gypsum powder mentioned is a calcined gypsum powder composed of one or more of the following: natural gypsum, desulfurized gypsum, phosphogypsum, high-strength gypsum, citric acid gypsum, titanium gypsum, lactic acid gypsum, and fluorogypsum.

[0018] The second objective of this invention is:

[0019] A method for preparing the aforementioned water-resistant, early-strength gypsum cementitious material is provided, comprising the following preparation steps:

[0020] The gypsum powder, modified high-alumina active minerals, inorganic mineral activators, biological water-repellent agents, inorganic phase reaction promoters, setting time regulators, and quartz sand are metered and then fed into a mixer for high-speed and uniform mixing to prepare the water-resistant, early-strength gypsum cementitious material.

[0021] The third objective of this invention is:

[0022] Applications of the aforementioned water-resistant, early-strength gypsum cementitious materials:

[0023] The water-resistant, early-strength gypsum cementitious material can be used in the preparation of gypsum adhesive products, plastering gypsum products, gypsum putty products, gypsum self-leveling products, paper-faced gypsum board, gypsum strip board, gypsum block, and gypsum ceiling board. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Any simple improvements to the preparation method of this invention based on the inventive concept are within the scope of protection of this invention.

[0025] Example 1

[0026] A gypsum-based ceramic tile adhesive formulated using water-resistant, early-strength gypsum cementitious materials, comprising the following preparation steps:

[0027] S1. Preparation of water-resistant, early-strength gypsum cementitious materials:

[0028] The gypsum powder, modified high-alumina active minerals, inorganic mineral activators, biological water-repellent agents, inorganic phase reaction promoters, setting time regulators, and quartz sand are metered and then fed into a mixer for high-speed and uniform mixing to prepare the water-resistant, early-strength gypsum cementitious material.

[0029] S2. According to specific needs, the cellulose ether, retarder, and thixotropic agent are metered and then transported to a mixer to be mixed evenly with the water-resistant, early-strength gypsum cementitious material prepared in step S1.

[0030] S3. According to specific needs, the inert filler is metered and then transported to a mixer to be mixed evenly with the material prepared in step S2, and finally the gypsum-based ceramic tile adhesive is prepared.

[0031] The preparation methods of Comparative Examples 1 to 4 are basically the same as those of Example 1. The main difference lies in the specific selection and dosage of raw materials, as detailed in Table 1.

[0032] Table 1. Specific raw material composition (parts by weight) of the gypsum-based ceramic tile adhesives in the examples and comparative examples.

[0033]

[0034]

[0035] The physical properties of the gypsum-based ceramic tile adhesive materials in the above embodiments and comparative examples were tested according to the methods specified in the JC / T 547-2017 "Ceramic Adhesives" standard, and the results are shown in Table 2 below.

[0036] Table 2. Physical performance test results of the examples and comparative products.

[0037]

[0038] The test results of the examples and comparative examples in Table 2 show that the water-resistant, early-strength gypsum cementitious material prepared using the present invention significantly improves the water-repellent properties of gypsum-based ceramic adhesives by adding a biological water-repellent agent (lycopodium powder). Generally, such biological water-repellent agents have excellent water-repellent effects, effectively preventing water penetration and thus enhancing the strength of gypsum cementitious materials under immersion conditions. However, lycopodium powder has limited effect on improving 1-day strength, freeze-thaw strength, and thermal aging strength due to its poor weather resistance and durability (see Comparative Example 1). On the other hand, while modified high-alumina fly ash can significantly improve thermal aging strength, its improvement on immersion strength and freeze-thaw strength is not significant. Modified high-alumina slag powder, on the other hand, can improve 1-day strength and freeze-thaw strength. Furthermore, compared with ordinary high-alumina fly ash and ordinary blast furnace slag powder, modified high-alumina fly ash and modified blast furnace slag powder have better enhancing effects on immersion strength, 1-day strength, thermal aging strength, and freeze-thaw strength.

[0039] In summary, the synergistic effect of biological water-repellent agents, modified high-alumina fly ash, and modified high-alumina slag powder can comprehensively improve the 1-day strength, water immersion strength, thermal aging strength, and freeze-thaw strength of gypsum cementitious materials. This comprehensive improvement enables gypsum-based ceramic adhesives to maintain good performance under various environmental conditions.

[0040] The gypsum-based tile adhesive prepared using the water-resistant, early-strength gypsum cementitious material obtained by the present invention has the following significant advantages:

[0041] Early strength enhancement: Due to the application of the water-resistant, early-strength gypsum cementitious material of the present invention, the gypsum-based tile adhesive exhibits high strength in the early stages, which helps to shorten the construction period and thus reduce the overall construction cost.

[0042] Enhanced tensile bond strength after immersion in water: The water-resistant, early-strength gypsum cementitious material of the present invention also improves the tensile bond strength of gypsum-based tile adhesive after immersion in water, which means that the adhesive can maintain its bonding performance even in a humid environment.

[0043] Enhanced tensile bond strength after freeze-thaw cycles: Furthermore, the gypsum-based tile adhesive using the water-resistant, early-strength gypsum cementitious material of the present invention can still maintain good tensile bond strength after experiencing freeze-thaw cycles, which further proves its reliability under extreme climatic conditions.

[0044] Expanded Application Scope: Due to the utilization of the water-resistant, early-strength gypsum cementitious material of this invention, the aforementioned properties of the gypsum-based tile adhesive are all improved. This also indicates that the gypsum-based tile adhesive of this invention is not only suitable for dry indoor areas but can also be safely used in damp indoor areas, providing users with more choices and convenience.

[0045] In summary, the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any changes, modifications, and evolutions made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content shall be considered equivalent embodiments of the present invention. Furthermore, any changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention shall still fall within the protection scope of the present invention.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] Experimental methods not specified in this invention are generally performed under conventional conditions or as recommended by the manufacturer.

[0048] Unless otherwise stated, the various optimized technical solutions in this invention can be combined with each other.

[0049] Unless otherwise stated, percentages and parts are weight percentages and weight parts.

[0050] Experimental methods not specified in the instructions and examples are generally performed under standard conditions or as recommended by the manufacturer.

[0051] The various raw materials, reagents and components used in this invention are all commonly used raw materials in the field unless otherwise stated.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in the methods of this invention.

Claims

1. A water-resistant, early-strength gypsum cementitious material, characterized in that: It comprises the following components in parts by weight: 30.0-85.0 parts of gypsum powder, 10.0-25.0 parts of modified high-alumina active minerals, 0.1-2 parts of inorganic mineral activator, 0.1-1 parts of biological hydrophobic agent, 2-8 parts of inorganic phase reaction promoter, 0.2-1 parts of setting time regulator, and 25.0-55.0 parts of quartz sand; The modified high-alumina active mineral is a mixture of power plant modified high-alumina fly ash and modified blast furnace slag powder; The modified high-alumina fly ash for power plants is a high-alumina fly ash with a specific surface area > 800 m² / kg and an alumina content ≥ 70%. The modified blast furnace slag powder is a blast furnace slag powder with a specific surface area > 800 m² / kg and an activity index ≥ 95 after 28 days. The inorganic mineral activator is one or a mixture of several of aluminum sulfate, potassium sulfate, sodium sulfate, potassium aluminum sulfate, sodium silicate, and potassium silicate; The aforementioned biological hydrophobic agent is the spore powder of the wild Lycopodium clavatum plant, also known as Lycopodium powder; The inorganic phase reaction promoting substance is one or a mixture of several of the following: calcium hydroxide, quicklime, silicate cement, sulfate cement, sulfoaluminate cement, and high-alumina cement. The setting time regulator is one or a mixture of two of the following: organic acid retarder, phosphate retarder, boric acid, amino acid retarder, and protein retarder.

2. The water-resistant, early-strength gypsum cementitious material according to claim 1, characterized in that: The gypsum powder mentioned is a calcined gypsum powder composed of one or more of the following: natural gypsum, desulfurized gypsum, phosphogypsum, high-strength gypsum, citric acid gypsum, titanium gypsum, lactic acid gypsum, and fluorogypsum.

3. A method for preparing the water-resistant, early-strength gypsum cementitious material according to claim 1, characterized in that: It includes the following preparation steps: The gypsum powder, modified high-alumina active minerals, inorganic mineral activators, biological water-repellent agents, inorganic phase reaction promoters, setting time regulators, and quartz sand are metered and then fed into a mixer for high-speed and uniform mixing to prepare the water-resistant, early-strength gypsum cementitious material.

4. An application of the water-resistant, early-strength gypsum cementitious material according to claim 1, characterized in that: The water-resistant, early-strength gypsum cementitious material can be used in the preparation of gypsum adhesive products, plastering gypsum products, gypsum putty products, gypsum self-leveling products, paper-faced gypsum board, gypsum strip board, gypsum block, and gypsum ceiling board.

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