An alkali-activated slag concrete and its preparation method

Abstract

This application relates to the field of concrete technology, and specifically discloses an alkali-activated slag concrete and a preparation method thereof. The alkali-activated slag concrete of this application is mainly made from the following raw materials: cement, water, recycled coarse aggregate, fine steel slag aggregate, slag, admixture, water glass, modified glass fiber. The preparation method of the modified glass fiber includes the following steps: impregnating glass fiber in methyl hydrogen silicone oil, taking it out and drying to obtain pretreated glass fiber; impregnating the pretreated glass fiber in an elastic solution, taking it out and drying to obtain the modified glass fiber. The elastic solution is mainly made from the following raw materials: acrylic emulsion, styrene-butadiene latex, calcium sulfate whisker, elasticizer, water, kaolin. The preparation method includes the following steps: mixing the recycled coarse aggregate, fine steel slag aggregate, slag, admixture, modified glass fiber, and water glass to obtain a mixture; mixing the cement and water, and adding the mixture to obtain the alkali-activated slag concrete. The concrete of this application has better waterproof performance and compressive strength.

Description

Technical Field

[0001] This application relates to the technical field of concrete preparation, and more specifically, to an alkali-activated slag concrete and a preparation method thereof. Background Art

[0002] Granulated blast furnace slag powder is the waste residue generated during ironmaking. It is ground after being quenched rapidly with water and has a special aluminosilicate structure. Slag is an active mineral material with potential hydraulicity. Since 2009, the annual output of granulated blast furnace slag in China has reached more than 200 million tons. The vast majority of granulated blast furnace slag is utilized by the cement and concrete industries and is the preferred material for realizing green, energy-saving, low-carbon and environmental protection in the production of concrete industry.

[0003] Compared with ordinary Portland cement concrete, alkali-activated slag concrete has the characteristic of fast setting time, which can effectively shorten the demolding time, and the structure can be loaded at an early stage, thus greatly accelerating the industrial production progress of precast components and shortening the construction period. The main raw materials of the cementitious material of alkali-activated slag concrete are industrial by-products or industrial waste residues, which are rich in resources and low in price.

[0004] At present, when alkali-activated slag concrete is applied to reinforced concrete structures, there are still some problems. Among them, carbonation is the reason for the low durability of reinforced concrete structures. When carbonation exceeds the concrete cover layer, in the presence of water and air, it will cause the concrete to lose its protective effect on the steel bars, thereby reducing the durability of the reinforced concrete structure.

[0005] In order to improve the durability of reinforced concrete structures, a waterproof coating is usually applied on the concrete surface to form a waterproof layer. However, the waterproof coating has poor use effect in actual use. Therefore, there is an urgent need to prepare an alkali-activated slag concrete with good waterproof performance. Summary of the Invention

[0006] In order to improve the waterproof property of alkali-activated slag concrete, this application provides an alkali-activated slag concrete and a preparation method thereof.

[0007] In the first aspect, this application provides an alkali-activated slag concrete, adopting the following technical solution:

[0008] An alkali-activated slag concrete is mainly made of the following raw materials in parts by weight: 20-30 parts of cement, 6-10 parts of water, 80-120 parts of recycled coarse aggregate, 60-70 parts of fine steel slag aggregate, 5-10 parts of slag, 0.5-1 part of admixture, 3-8 parts of modified glass fiber, and 2-3 parts of water glass. The preparation method of the modified glass fiber comprises the following steps: S1, pretreatment of glass fiber: immersing the glass fiber in methyl hydrogen silicone oil, taking it out and drying it, Pretreated glass fiber is obtained; S2, preparation of modified glass fiber: the pretreated glass fiber obtained in step S1 is immersed in an elastic solution, taken out, and dried to obtain the modified glass fiber, wherein the elastic solution is mainly made of the following raw materials in parts by weight: 10-20 parts of acrylic emulsion, 10-20 parts of styrene-butadiene latex, 2-3 parts of calcium sulfate whiskers, 5-10 parts of elastic agent, 5-10 parts of water, and 3-5 parts of kaolin, and the elastic agent is at least one of rubber particles and polyurethane elastomer.

[0009] By adopting the above technical solution, the present application adds modified glass fiber to concrete. The modified glass fiber is prepared by immersing the glass fiber in an elastic solution. The elastomer in the elastic solution adheres to the surface of the glass fiber under the action of acrylic emulsion to form an elastic layer. The elastomers abut against each other, which helps to increase the density of the concrete. The elastomer has good hydrophobicity, so as to further enhance the waterproofness of the concrete. There are countless fine grooves on the surface of the glass fiber, which is an irregular ellipse in the horizontal direction, and is covered with pores on the cross section and has cracks on the edges. Therefore, the content of acrylic emulsion on the surface of the glass fiber is increased, and the stability of the distribution of the elastomer on the surface of the glass fiber is further enhanced, thereby improving the compressive strength and waterproofness of the concrete.

[0010] Preferably, the elastic agent is composed of rubber particles and polyurethane elastomer in a mass ratio of (1-2): (4-5).

[0011] By adopting the above technical solution, the elastomer is obtained by compounding two components, rubber particles and polyurethane elastomer, and the mass ratio of the two components is adjusted to optimize the mass ratio of the two components. Polyurethane elastomer is a block polymer, generally composed of two parts, hard segments and soft segments. The hard segments are arranged alternately in an orderly manner to form a repeating structural crystalline unit, which gives the elastomer properties such as high strength, rigidity and high melting point; the soft segments are arranged in a disordered curling to form an amorphous region, which gives the elastomer flexibility, elasticity, hygroscopicity and low-temperature resistance; polyurethane elastomer has excellent wear resistance, toughness and high elasticity, and polyurethane elastomer has good compatibility with rubber particles. Rubber particles are not water-absorbent, and their surfaces have irregular convex and concave shapes and are relatively rough, which have good compatibility with polyurethane elastomer, helping to further enhance the stability and strength of the elastic layer on the surface of the glass fiber.

[0012] Preferably, the particle size ratio of the rubber particles to the polyurethane elastomer is (5 - 7):(1 - 2).

[0013] Preferably, the rubber particles are ethylene propylene diene monomer (EPDM) rubber particles.

[0014] By adopting the above technical solution, the particle sizes of the two substances, namely the rubber particles and the polyurethane elastomer, are adjusted so that the particle size ratio of the two components reaches the optimum, in order to better exert the elastic effects of the rubber particles and the polyurethane elastomer, improve the elastic strength and elastic stability of the elastic layer formed on the surface of the glass fiber. The particle size of the rubber particles is larger than that of the polyurethane elastomer. The rubber particles are distributed on the surface of the glass fiber to form the framework of the elastic layer, and pores are formed between adjacent rubber particles. The polyurethane elastomer is filled in the pores formed by the rubber particles to improve the density of the elastic layer, and further improve the strength of the elastic layer.

[0015] Preferably, the rubber particles are modified rubber particles. The preparation method of the modified rubber particles includes the following steps: roughen the rubber particles, immerse them in styrene-acrylic emulsion to obtain pretreated rubber particles, and mix the pretreated rubber particles with chopped basalt fibers and then dry them to obtain the modified rubber particles.

[0016] By adopting the above technical solution, after the rubber particles are roughened, their surfaces become rougher, the surface area in contact with the styrene-acrylic emulsion is larger, the content of the styrene-acrylic emulsion adhered to the surface of the rubber particles increases, and the viscosity increases, which is convenient for increasing the adhesion stability of the chopped basalt fibers on the surface of the rubber particles. The chopped basalt fibers form an interlaced network structure on the surface of the rubber particles, and the chopped basalt fibers have better mechanical properties and compatibility, with high tensile strength, high elastic modulus and corrosion resistance, so as to enhance the strength of the rubber particles, and further enhance the strength of the elastic layer, and then improve the strength of the modified glass fiber.

[0017] Preferably, the glass fiber is a mesh glass fiber.

[0018] By adopting the above technical solution, the appearance of the mesh glass fiber is a mesh structure formed by the interconnection of multiple glass fiber filaments. When the mesh glass fiber is put into the concrete, during the concrete mixing process, the transverse connection between the fiber filaments is damaged by the kneading and friction of the concrete itself, forming single filaments or a fully opened mesh structure, so as to achieve the effect of strengthening the concrete with a large number of modified mesh glass fibers.

[0019] Preferably, the concrete further includes 3 - 5 parts of a waterproofing agent, and the waterproofing agent is composed of bentonite and tetrapod-like zinc oxide whiskers in a mass ratio of (1 - 2):(3 - 5).

[0020] By adopting the above technical solution, montmorillonite crystals in bentonite have large ion exchange properties. When montmorillonite encounters water, water molecules can enter between the unit crystal layers of bentonite, causing lattice expansion. After contacting water for 48 hours, it is completely hydrated. Hydration causes the water absorption and swelling volume of bentonite to increase, thus forming a natural water barrier, which may block the water transmission channels in concrete. Moreover, bentonite has a migration effect and may fill the cracks formed in concrete; the structure of tetrapod-shaped zinc oxide whiskers is a tetrapod-shaped three-dimensional structure. Based on the three-dimensional structure of tetrapod-shaped zinc oxide whiskers, tetrapod-shaped zinc oxide whiskers are easily evenly distributed in concrete and cooperate synergistically with modified glass fibers in concrete to jointly play a skeletal role.

[0021] Preferably, the bentonite is modified bentonite. The preparation method of the modified bentonite includes the following steps: uniformly mixing rubber powder, kaolin, bentonite, and water, drying and pulverizing to obtain it.

[0022] Preferably, the mass ratio of the bentonite to water is 1:(10 - 20).

[0023] Preferably, the mass ratio of the bentonite, rubber powder, and kaolin is 1:(5 - 8):(2 - 3).

[0024] Preferably, the particle size ratio of the kaolin is 5 - 10 μm.

[0025] By adopting the above technical solution, after the bentonite is mixed with the rubber powder, the free bound water of the bentonite becomes more and more and tends to be stable, the free water of the consolidated body decreases, the porosity in the grout decreases, and the grout consolidated body becomes denser, so the permeability coefficient decreases; for the bentonite modified by the rubber powder, its interlayer structure changes, having stronger bonding ability and adsorption. It fills the gaps in the cement stone skeleton, improves the particle size distribution, pore structure and pore size distribution of the consolidated body, extends the seepage path, weakens the seepage effect, makes it difficult for external water molecules to invade, shows sufficient water stability, and improves the impermeability; after the bentonite is modified, it has high adsorption and cohesion, adsorbs the fine particles brought by the seepage water and further hydrates the cement in the seepage channel, resulting in the blockage of the channel, so as to further improve the waterproof performance of the concrete.

[0026] Preferably, the particle size distribution of the bentonite is that the mass ratio of 6 - 8 mm is 30 - 35%, the mass ratio of 8 - 15 mm is 25 - 35%, the mass ratio of 15 - 25 mm is 25 - 30%, and the mass ratio of 25 - 30 mm is 10 - 25%.

[0027] By adopting the above technical solution, bentonite adopts a variety of particle size gradations. The addition of small-particle bentonite increases the density of concrete, makes the concrete particles arranged closely, and greatly reduces the pores. In addition, the bentonite with a variety of particle size gradations is distributed more evenly in the concrete, which helps to better block the channels for water transmission in the concrete, thereby improving the waterproofness of the concrete.

[0028] Preferably, the admixture is a sulfamate-based water reducer.

[0029] Preferably, the recycled coarse aggregate particle size gradation is 10-15 mm, accounting for 25-35% by mass; 15-20 mm, accounting for 55-60% by mass; and 20-30 mm, accounting for 10-25% by mass.

[0030] By adopting the above technical solution, the particle size gradation of recycled coarse aggregate improves the compressive strength of concrete while improving the waterproof performance of concrete, so that the strength and waterproof performance of the mixed concrete are more suitable for actual production and application.

[0031] In a second aspect, the present application provides a method for preparing alkali-activated slag concrete, which adopts the following technical solution: A method for preparing alkali-activated slag concrete, comprising the following steps:

[0032] (1) Preparation of a mixture: mixing recycled coarse aggregate, fine steel slag aggregate, slag, admixture, modified glass fiber, and water glass to obtain a mixture;

[0033] (2) Concrete preparation: Mix cement and water, then add the mixture obtained in step (1), mix well, and obtain the concrete.

[0034] By adopting the above technical solution, the concrete prepared in the present application has a simple and easy preparation method, and the prepared concrete has excellent waterproof and compressive properties.

[0035] Preferably, the waterproofing agent is added in step (1).

[0036] By adopting the above technical solution, the addition of waterproofing agent helps to improve the waterproofness of concrete, so as to improve the durability of reinforced concrete structures.

[0037] In summary, this application has the following beneficial effects:

[0038] 1. Modified glass fibers are added to the alkali-activated slag concrete of the present application. The modified glass fibers are wrapped with an elastic layer. Part of the elastomers in the elastic layer abut against each other, thereby enhancing the density of the elastic layer. At the same time, adjacent modified glass fibers absorb water and expand, further enhancing the abutting force between adjacent modified glass fibers, thereby enhancing the compressive strength and waterproofness of the concrete.

[0039] 2. A waterproofing agent is added to the alkali-activated slag concrete of the present application. The waterproofing agent is obtained by compounding bentonite and tetrapod zinc oxide whiskers. The addition of the waterproofing agent improves the waterproof property of the concrete on the one hand, and on the other hand, the entanglement of the tetrapod zinc oxide whiskers and the modified glass fiber enhances the stability of the network structure, thereby enhancing the compressive strength of the concrete. Detailed implementation manners

[0040] The present application will be further described in detail below with reference to the embodiments.

[0041] Preparation examples of modified glass fiber

[0042] Preparation example 1; A preparation method of modified glass fiber, comprising the following steps:

[0043] S1. Glass fiber pretreatment: Immerse the glass fiber in methyl hydrogen silicone oil for 5 minutes, take it out and dry it to obtain pretreated glass fiber;

[0044] S2. Preparation of modified glass fiber: Immerse the pretreated glass fiber obtained in step S1 in an elastic solution for 30 minutes, take it out and dry it to obtain the modified glass fiber. Among them, the elastic solution includes the following raw materials by weight: 10 kg of acrylic emulsion, 10 kg of styrene-butadiene latex, 2 kg of calcium sulfate whiskers, 5 kg of elasticizer, 5 kg of water, and 3 kg of kaolin. The elasticizer is rubber particles. The rubber particles are ethylene-propylene-diene monomer rubber particles.

[0045] Preparation example 2: A preparation method of modified glass fiber, different from preparation example 1 in that: the elastic solution includes the following raw materials by weight: 20 kg of acrylic emulsion, 20 kg of styrene-butadiene latex, 3 kg of calcium sulfate whiskers, 10 kg of elasticizer, 10 kg of water, and 5 kg of kaolin.

[0046] Preparation example 3: A preparation method of modified glass fiber, different from preparation example 2 in that: the elasticizer is composed of rubber particles and polyurethane elastomer in a mass ratio of 1:1. The particle size ratio of the rubber particles to the polyurethane elastomer is 1:1.

[0047] Preparation example 4: A preparation method of modified glass fiber, different from preparation example 3 in that: the elasticizer is composed of rubber particles and polyurethane elastomer in a mass ratio of 1:4.

[0048] Preparation example 5: A preparation method of modified glass fiber, different from preparation example 3 in that: the elasticizer is composed of rubber particles and polyurethane elastomer in a mass ratio of 2:5.

[0049] Preparation example 6: A preparation method of modified glass fiber, different from preparation example 5 in that: the particle size ratio of the rubber particles to the polyurethane elastomer is 5:1.

[0050] Preparation Example 7: A method for preparing modified glass fibers, which is different from Preparation Example 5 in that the particle size ratio of rubber particles to polyurethane elastomer is 7:2.

[0051] Preparation Example 8: A method for preparing modified glass fibers, which is different from Preparation Example 7 in that the rubber particles are modified rubber particles. The method for preparing the modified rubber particles includes the following steps: roughening the rubber particles, impregnating them in styrene-acrylic emulsion for 5 minutes to obtain pretreated rubber particles, and mixing the pretreated rubber particles with chopped basalt fibers and drying them to obtain the modified rubber particles. The roughening treatment method includes the following steps: placing the rubber particles in an acidic solution for corrosion treatment for 13 seconds. The acidic solution is a sulfuric acid solution with a molar concentration of 1 mol / L.

[0052] Preparation Example 9: A method for preparing modified glass fibers, which is different from Preparation Example 8 in that the glass fibers are reticulated glass fibers.

[0053] Examples

[0054] Example 1: An alkali-activated slag concrete, comprising the following raw materials by weight: 20 kg of cement, 6 kg of water, 80 kg of recycled coarse aggregate, 60 kg of fine steel slag aggregate, 5 kg of slag, 0.5 kg of admixture, 3 kg of modified glass fibers, and 2 kg of water glass. Among them, the modified glass fibers are prepared according to Preparation Example 1, the cement is P.O 42.5 ordinary Portland cement, the recycled coarse aggregate is obtained by mixing construction solid waste and slag in a mass ratio of 1:1, the particle size distribution of the recycled coarse aggregate is 35% by mass of 10-15 mm, 55% by mass of 15-20 mm, and 10% by mass of 20-30 mm. The fine steel slag aggregate is steel slag with a particle size less than 5 mm, and the admixture is an amino sulfonate-based water reducer.

[0055] Example 2: An alkali-activated slag concrete, which is different from Example 1 in that it comprises the following raw materials by weight: 30 kg of cement, 10 kg of water, 120 kg of recycled coarse aggregate, 70 kg of fine steel slag aggregate, 10 kg of slag, 1 kg of admixture, 8 kg of modified glass fibers, and 3 kg of water glass. Among them, the modified glass fibers are prepared according to Preparation Example 2.

[0056] Table 1 Modified glass fibers for alkali-activated slag concrete in Examples 1-9

[0057] Serial number Modified glass fiber Example 1 Preparation Example 1 Example 2 Preparation Example 2 Example 3 Preparation Example 3 Example 4 Preparation Example 4 Example 5 Preparation Example 5 Example 6 Preparation Example 6 Example 7 Preparation Example 7 Example 8 Preparation Example 8 Example 9 Preparation Example 9

[0058] Examples 3-9: An alkali-activated slag concrete, which is different from Example 2 in that the modified glass fibers are prepared according to different preparation examples.

[0059] Example 10: An alkali-activated slag concrete, which is different from Example 2 in that it comprises raw materials with the following weights: 30 kg of cement, 10 kg of water, 120 kg of recycled coarse aggregate, 70 kg of fine steel slag aggregate, 10 kg of slag, 1 kg of admixture, 8 kg of modified glass fiber, and 4 kg of waterproofing agent, wherein the waterproofing agent is composed of bentonite and tetrapod zinc oxide whiskers in a mass ratio of 1:4. The particle size of the bentonite is 15 mm.

[0060] A preparation method of an alkali-activated slag concrete comprises the following steps:

[0061] (1) Preparation of the mixture: Mix the recycled coarse aggregate, fine steel slag aggregate, slag, admixture, modified glass fiber, water glass, and waterproofing agent to obtain a mixture;

[0062] (2) Preparation of the concrete: Mix the cement and water, and then add the mixture obtained in step (1), and mix evenly to obtain the concrete.

[0063] Example 11: An alkali-activated slag concrete, which is different from Example 10 in that the bentonite is modified bentonite, and the preparation method of the modified bentonite comprises the following steps: Mix the rubber powder, kaolin, bentonite, and water evenly, dry and crush them to obtain the modified bentonite. Among them, the mass ratio of bentonite to water is 1:15; the mass ratio of bentonite, rubber powder, and kaolin is 1:8:3; the particle size of the kaolin is 8 μm.

[0064] Example 12: An alkali-activated slag concrete, which is different from Example 10 in that the particle size distribution of the bentonite is 30% by mass of 6-8 mm, 30% by mass of 8-15 mm, 30% by mass of 15-25 mm, and 10% by mass of 25-30 mm.

[0065] Comparative Examples

[0066] Comparative Example 1: An alkali-activated slag concrete, which is different from Example 1 in that equal amounts of glass fiber are used to replace the modified glass fiber.

[0067] Comparative Example 2: An alkali-activated slag concrete, which is different from Example 1 in that no elasticizer is added.

[0068] Testing Method

[0069] Mechanical property testing: Take the alkali-activated slag concretes prepared in Examples 1-12 and Comparative Examples 1-2, and in accordance with the testing method in JC474-2008 "Waterproofing Agents for Mortars and Concretes", test the compressive strength ratio and water absorption ratio of the alkali-activated slag concrete, and the test results are shown in Table 2.

[0070] Table 2 Mechanical Property Testing of Alkali-Activated Slag Concretes in Examples 1-12 and Comparative Examples 1-2

[0071]

[0072]

[0073] Combining Example 1 and Comparative Example 1, and in combination with the data in Table 2, it can be seen that the compressive strength ratio and water absorption ratio of the concrete prepared in Example 1 are superior to those of the concrete prepared in Comparative Example 1. The difference between Example 1 and Comparative Example 1 is that: the fiber in Example 1 is a modified glass fiber, while Comparative Example 1 uses ordinary glass fiber. The inventors of the present application believe that: by treating the glass fiber, an elastic layer is wrapped outside the glass fiber, which is convenient for improving the compressive strength ratio and water absorption ratio of the prepared concrete, and further improving the performance of the prepared concrete.

[0074] Combining Example 1 and Comparative Example 2, and in combination with the data in Table 2, it can be seen that the concrete prepared in Example 1 has a relatively high compressive strength and a relatively low water absorption, and the performance of the prepared concrete is better. The difference between Example 1 and Comparative Example 2 is that: an elasticizer is added in Example 1. The inventors of the present application believe that: the addition of the elasticizer improves the waterproofness and compressive strength of the elastic layer on the surface of the glass fiber, and further improves the waterproofness and compressive strength of the prepared concrete.

[0075] Combining Examples 1-2, and in combination with the data in Table 2, it can be seen that the waterproofness and compressive strength of the concrete prepared in Examples 1-2 are better. The inventors of the present application believe that: by adjusting the proportion of each component of the elastic solution and the concrete raw materials, the performance of the prepared concrete is better.

[0076] Combining Examples 2-5, and in combination with the data in Table 2, it can be seen that the waterproofness and compressive strength of the concrete prepared in Examples 3-5 are better. The inventors of the present application believe that: by adjusting the components and the proportion of the elasticizer, the waterproofness and compressive strength of the elastic layer formed on the surface of the glass fiber are both better, so as to improve the waterproofness and compressive strength of the concrete.

[0077] Combining Examples 5-7, and in combination with the data in Table 2, it can be seen that the concrete prepared in Examples 6-7 has a relatively high compressive strength and a relatively low water absorption, indicating that the prepared concrete has a relatively high compressive strength and strong waterproofness. The inventors of the present application believe that: the elasticizer is obtained by compounding rubber particles and polyurethane elastomer, and by adjusting the particle size ratio of the two components, the density of the elastic layer is adjusted, and further the compressive strength and waterproofness of the modified glass fiber are improved, so as to improve the compressive strength and waterproofness of the concrete prepared from the modified glass fiber.

[0078] Combined with Examples 7-8 and the data in Table 2, it can be seen that the compressive strength ratio of the concrete prepared in Example 8 is higher than that of the concrete prepared in Example 7, and the water absorption is relatively low. The difference between Example 8 and Example 7 is that the rubber particles in Example 8 are modified and short-cut basalt fibers are adhered to the surface. The inventors of the present application believe that: after the rubber particles are modified and short-cut basalt fibers are adhered to the surface, it is convenient to improve the strength of the rubber particles. At the same time, the role of the rubber particles in the elastic layer is improved, thereby improving the strength and waterproofness of the modified glass fiber, and further improving the compressive strength and waterproofness of the prepared concrete.

[0079] Combined with Examples 8-9 and the data in Table 2, it can be seen that the compressive strength ratio of the concrete prepared in Example 9 is higher than that of the concrete prepared in Example 8, and the water absorption is relatively low. The difference between Example 9 and Example 8 is that the glass fiber in Example 9 is a mesh glass fiber, and the compressive strength of the concrete prepared therefrom is better.

[0080] Combined with Example 2 and Example 10 and the data in Table 2, it can be seen that the concrete prepared in Example 10 has a relatively high compressive strength and good waterproofness. The inventors of the present application believe that: adding a waterproof agent to the concrete can, on the one hand, improve the waterproofness of the concrete, and on the other hand, improve the compressive strength of the concrete.

[0081] Combined with Examples 10-11 and the data in Table 2, it can be seen that the concrete prepared in Example 11 has better waterproofness and the compressive strength has also been improved. The difference between Example 11 and Example 10 is that the bentonite in Example 11 is modified with rubber powder. The inventors of the present application believe that: after the bentonite is modified with rubber powder, the waterproofness is better, and the adhesion between the bentonite and other components of the concrete is improved, which helps to enhance the compressive strength of the concrete.

[0082] Combined with Example 10 and Example 12 and the data in Table 2, it can be seen that the water absorption of the concrete prepared in Example 12 is relatively low. The difference between Example 12 and Example 10 is that the bentonite in Example 12 adopts a particle size grading method, which is convenient to improve the distribution of the bentonite in the concrete, and further improve the waterproofness and compressive strength of the concrete.

[0083] This specific embodiment is only an explanation of the present application, and it is not a limitation of the present application. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An alkali-activated slag concrete, characterized in that, It is mainly made of the following raw materials in parts by weight: 20 - 30 parts of cement, 6 - 10 parts of water, 80 - 120 parts of recycled coarse aggregate, 60 - 70 parts of fine steel slag aggregate, 5 - 10 parts of slag, 0.5 - 1 part of admixture, 3 - 8 parts of modified glass fiber, 2 - 3 parts of water glass. The preparation method of the modified glass fiber includes the following steps: S1. Pretreatment of glass fiber: Immerse the glass fiber in methyl hydrogen silicone oil, take it out and dry it to obtain pretreated glass fiber; S2. Preparation of modified glass fiber: Immerse the pretreated glass fiber obtained in step S1 in an elastic solution, take it out and dry it to obtain the modified glass fiber. The elastic solution is mainly made of the following raw materials in parts by weight: 10 - 20 parts of acrylic emulsion, 10 - 20 parts of styrene - butadiene latex, 2 - 3 parts of calcium sulfate whisker, 5 - 10 parts of elasticizer, 5 - 10 parts of water, 3 - 5 parts of kaolin. The elasticizer is composed of rubber particles and polyurethane elastomer in a mass ratio of (1 - 2):(4 - 5), and the particle size ratio of the rubber particles to the polyurethane elastomer is (5 - 7):(1 - 2); The rubber particles are modified rubber particles. The preparation method of the modified rubber particles includes the following steps: Roughen the rubber particles, immerse them in styrene - acrylic emulsion to obtain pretreated rubber particles, mix the pretreated rubber particles with chopped basalt fiber, and dry them to obtain the modified rubber particles.

2. The alkali-activated slag concrete according to claim 1, characterized in that: The glass fiber is reticulated glass fiber.

3. The alkali-activated slag concrete according to claim 1, wherein: The concrete also includes 3 - 5 parts of waterproof agent. The waterproof agent is composed of bentonite and tetrapod - shaped zinc oxide whisker in a mass ratio of (1 - 2):(3 - 5).

4. An alkali-activated slag concrete according to claim 3, characterized in that: The bentonite is modified bentonite. The preparation method of the modified bentonite includes the following steps: Mix rubber powder, kaolin, bentonite and water evenly, dry and crush them to obtain the modified bentonite.

5. The alkali-activated slag concrete according to claim 3, wherein: The particle size distribution of the bentonite is that the mass ratio of 6 - 8mm is 30 - 35%, the mass ratio of 8 - 15mm is 25 - 35%, the mass ratio of 15 - 25mm is 25 - 30%, and the mass ratio of 25 - 30mm is 10 - 25%.

6. A preparation method of an alkali-activated slag concrete according to any one of claims 1-5, characterized in that: It includes the following steps: (1) Preparation of the mixture: Mix the recycled coarse aggregate, fine steel slag aggregate, slag, admixture, modified glass fiber and water glass to obtain a mixture; (2) Preparation of concrete: Mix cement and water, then add the mixture obtained in step (1) and mix evenly to obtain the concrete.

7. The preparation method of the alkali-activated slag concrete according to claim 6, characterized in that: The waterproof agent is added in step (1).

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