Basalt-doped cement mortar and preparation method thereof

Abstract

The invention discloses cement mortar doped with basalt and a preparation method of the cement mortar, relates to the technical field of building materials, and aims to improve the mechanical property, high-temperature fire resistance and self-repairing capability of the cement mortar through a specific raw material ratio and process. The cement mortar is prepared from basalt aggregate, Portland cement, steelmaking slag, polysilazane, expanded polystyrene, repairing capsules, a polycarboxylic acid high-performance water reducing agent and water. The preparation method comprises the following steps: performing dry mixing on the basalt aggregate, the cement and other raw materials, spraying the polysilazane, adding the water reducing agent solution, the expanded polystyrene and the repairing capsule, and stirring until slurry is fluidized. Experiments show that the cement mortar has significantly improved compressive strength, breaking strength and high-temperature fire resistance, also has a self-repairing function, and can effectively repair cracks and prolong the service life.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment agents, in particular to a cement mortar mixed with basalt and a preparation method thereof. Background Art

[0002] With the rapid development of modern construction technology, concrete, as an indispensable material in the construction field, has continuously improved its performance requirements. However, traditional concrete has obvious deficiencies in mechanical properties and high-temperature fire resistance. The compressive strength and tensile strength of ordinary concrete are relatively low, which makes it difficult to meet the application requirements under complex stress states; at the same time, in high temperature environments, concrete is prone to lose strength, leading to structural damage. This problem is particularly prominent under extreme conditions such as fire, which seriously affects the safety and durability of buildings.

[0003] To solve the above problems, researchers are constantly exploring new methods to improve the performance of concrete. Among them, adding special aggregates and functional additives is an effective way. For example, basalt, as a natural volcanic rock, has excellent heat resistance and mechanical properties, and can significantly improve the high-temperature fire resistance and mechanical strength of concrete. In addition, the introduction of materials such as polysilazane and expanded polystyrene not only enhances the thermal insulation performance of concrete, but also makes it lightweight, further expanding its application range in the field of construction. However, the shortcomings of existing concrete in mechanical properties, high-temperature fire resistance and durability still prompt researchers to continuously seek new materials and technological breakthroughs. In this context, the present invention proposes a cement mortar mixed with basalt, which aims to comprehensively improve the comprehensive performance of concrete by optimizing the raw material ratio and improving the preparation process to meet the needs of modern buildings for high-performance concrete. Summary of the invention

[0004] The purpose of the present invention is to provide a cement mortar mixed with basalt and a preparation method thereof, so as to solve the problems raised in the background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A cement mortar mixed with basalt comprises the following raw materials in parts by weight: 230-300 parts of basalt aggregate; 90-160 parts of Portland cement; 11-13 parts of steelmaking slag; 6-10 parts of polysilazane; 44-56 parts of expanded polystyrene; 24-28 servings of repair capsules; 0.8-1.5 parts of polycarboxylic acid high performance water reducer; 160-220 parts of water.

[0006] Furthermore, the basalt aggregate is composed of basalt coarse aggregate and basalt fine aggregate, the particle size of the basalt coarse aggregate is 8-20 mesh, and the particle size of the basalt fine aggregate is 325-400 mesh.

[0007] Furthermore, the mass ratio of the basalt coarse aggregate to the basalt fine aggregate is 7:1 to 10:1.

[0008] Furthermore, the CaO content in the steelmaking slag is 36%-40%.

[0009] Furthermore, the cement is PO42.5 grade Portland cement.

[0010] Furthermore, the preparation method of the expanded polystyrene is as follows: sodium carboxymethyl starch and alkylphenol polyoxyethylene ether are added to an aqueous solution containing 5wt% sodium alginate, and high-speed shearing is performed at 500-800rpm for 15-20min under 40°C-50°C water bath conditions to obtain a stable aqueous phase; styrene monomer, azodicarbonamide, ammonium persulfate, hexaphenoxy cyclotriphosphazene and toluene are mixed, and ultrasonic dispersion is performed for 20-30min to obtain an oil phase; the oil phase is gradually added to the aqueous phase, stirring is maintained at 800rpm to form a uniform emulsion, the temperature is raised to 60°C for reaction for 25-30min, the temperature is raised to 80°C for reaction for 30-40min, the temperature is raised to 90°C for reaction for 3-5h, and after cooling, washing, filtering and drying are performed to obtain the expanded polystyrene; Furthermore, the weight proportions of the sodium carboxymethyl starch, alkylphenol polyoxyethylene ether, 5wt% sodium alginate aqueous solution, styrene monomer, azodicarbonamide, ammonium persulfate, hexaphenoxy cyclotriphosphazene, and toluene are respectively 10-15 parts of sodium carboxymethyl starch, 2-3 parts of alkylphenol polyoxyethylene ether, 120-200 parts of 5wt% sodium alginate aqueous solution, 42-52 parts of styrene monomer, 1-3 parts of azodicarbonamide, 0.1-0.3 parts of ammonium persulfate, 5-8 parts of hexaphenoxy cyclotriphosphazene, and 30-45 parts of toluene.

[0011] Furthermore, the preparation method of the repair capsule is as follows: epoxy resin and acetone are mixed and dissolved, a curing agent is added, and a uniform core material solution is formed by ultrasonic dispersion and vacuum degassing; chitosan, acetic acid solution and gelatin are mixed, the pH is adjusted to 4-5, glutaraldehyde is added, stirred and reacted for 2 hours, and a wall material solution is obtained after cooling; Tween-80 emulsifier is added to the core material solution and the wall material solution, an emulsion is formed by high-pressure homogenization, CaCl2 is added, the reaction is carried out at 55°C-60°C for 2-3 hours, and a repair capsule is obtained by spray drying.

[0012] Furthermore, the curing agent is dicyandiamide.

[0013] Furthermore, the mass proportions of the epoxy resin, acetone, dicyandiamide, chitosan, acetic acid solution, gelatin, glutaraldehyde, Tween-80 emulsifier, and NH4Cl are respectively 30-48 parts of epoxy resin, 10-15 parts of acetone, 5-8 parts of dicyandiamide, 20-30 parts of chitosan, 50-70 parts of acetic acid solution, 10-20 parts of gelatin, 0.2-0.5 parts of glutaraldehyde, 2-3 parts of Tween-80 emulsifier, and 0.2-0.5 parts of CaCl2.

[0014] Furthermore, the acetic acid solution is an acetic acid aqueous solution with a mass fraction of 1%.

[0015] Furthermore, the water content of the polycarboxylic acid high-performance water-reducing agent is less than 2.8%, and the water reduction rate is greater than 25%.

[0016] A method for preparing cement mortar mixed with basalt, the specific steps are as follows: S1. Dry mix basalt aggregate, silicate cement and steelmaking slag for 3-5 minutes, spray polysilazane, set the stirring speed to 60-80 rpm, and continue stirring for 2-3 minutes to obtain a primary mixture; S2. Dissolve the polycarboxylic acid high-performance water-reducing agent in water, stir the mixture with a homogenizer at a speed of 1000-1500 rpm for 3-5 minutes to obtain a polycarboxylic acid high-performance water-reducing agent solution, pour half of the water-reducing agent solution into the primary mixture and stir for 3-5 minutes, control the mixer speed at 100-120 rpm, add expanded polystyrene, introduce nitrogen, control the flow rate at 0.5-1.0 L / min, continue stirring for 3-5 minutes, add the repair capsule, stir for 3-5 minutes, add the remaining water-reducing agent solution in batches, until the slurry is completely fluidized in the mixer, and obtain cement mortar mixed with basalt.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Expanded polystyrene forms a microporous structure in the mortar, which can provide a release space for the water vapor generated by the decomposition of cement hydration products at high temperature, thereby reducing the pressure inside the mortar and reducing the risk of high-temperature bursting.

[0018] 2. The present invention significantly improves the compressive strength and flexural strength of cement mortar by reasonably mixing basalt aggregate, silicate cement, polysilazane, expanded polystyrene and other ingredients.

[0019] 3. The present invention imparts a certain self-repairing function to cement mortar by adding repair capsules. When cracks appear in the cement mortar, the microcapsules rupture and release the repair agent, which can partially repair the cracks. DETAILED DESCRIPTION

[0020] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Embodiment 1:

[0022] A method for preparing cement mortar mixed with basalt, the specific process is as follows: 1. Preparation of foam polystyrene: Add 12 parts of sodium carboxymethyl starch and 2.5 parts of alkylphenol polyoxyethylene ether to 160 parts of an aqueous solution containing 5 wt% of sodium alginate, and shear at 600 rpm for 18 minutes in a 45°C water bath to obtain a stable aqueous phase; 48 parts of styrene monomer, 2 parts of azodicarbonamide, 0.2 parts of ammonium persulfate, 6 parts of hexaphenoxycyclotriphosphazene and 38 parts of toluene are mixed and ultrasonically dispersed for 25 minutes to obtain an oil phase; the oil phase is gradually added to the aqueous phase, stirred at 800 rpm to form an emulsion, and the temperature is raised to 60°C for reaction for 28 minutes, 80°C for reaction for 35 minutes, and 90°C for reaction for 4 hours, and filtered and dried after cooling.

[0023] 2. Preparation of repair microcapsules: Mix and dissolve 39 parts of epoxy resin and 12 parts of acetone, add 6 parts of dicyandiamide, and form a uniform core material solution through ultrasonic dispersion and vacuum degassing; mix 25 parts of chitosan, 65 parts of acetic acid solution and 16 parts of gelatin, adjust the pH to 4.5, add 0.4 parts of glutaraldehyde, stir and react for 2 hours, and obtain the wall material solution after cooling; add 2 parts of Tween-80 emulsifier to the core material solution and the wall material solution, form an emulsion through high-pressure homogenization, add 0.5 parts of CaCl2, react at 56°C for 2-3 hours, and spray dry to obtain the repair capsules.

[0024] 3. Preparation of cement mortar mixed with basalt: S1, dry-mix 210 parts of basalt aggregate, 30 parts of fine aggregate, 120 parts of Portland cement, and 12 parts of steelmaking slag for 4 minutes, spray 8 parts of polysilazane, and stir at 70 rpm for 2.5 minutes to obtain a primary mixture; S2. Dissolve 1.2 parts of polycarboxylic acid high-performance water-reducing agent in 180 parts of water, stir at 1200rpm for 4min to obtain a polycarboxylic acid high-performance water-reducing agent solution, pour half of the polycarboxylic acid high-performance water-reducing agent solution into the primary mixture and stir for 3-5min, control the mixer speed at 120rpm, add expanded polystyrene, introduce nitrogen, control the flow rate at 0.8 L / min, continue stirring for 5min, add repair capsules, stir for 3min, add the remaining polycarboxylic acid high-performance water-reducing agent solution in batches, until the slurry is completely fluidized in the mixer, and obtain cement mortar mixed with basalt.

[0025] Embodiment 2:

[0026] A method for preparing cement mortar mixed with basalt, the specific process is as follows: 1. Preparation of expanded polystyrene: Add 15 parts of sodium carboxymethyl starch and 3 parts of alkylphenol polyoxyethylene ether to 200 parts of an aqueous solution containing 5 wt% of sodium alginate, and shear at 800 rpm for 15 min in a 50°C water bath to obtain a stable aqueous phase; 52 parts of styrene monomer, 3 parts of azodicarbonamide, 0.3 parts of ammonium persulfate, 8 parts of hexaphenoxycyclotriphosphazene and 45 parts of toluene are mixed and ultrasonically dispersed for 20 min to obtain an oil phase; the oil phase is gradually added to the aqueous phase, stirred at 800 rpm to form an emulsion, and the temperature is raised to 60°C for reaction for 30 min, 80°C for reaction for 40 min, and 90°C for reaction for 3 hours, and filtered and dried after cooling.

[0027] 2. Preparation of repair capsules: Mix and dissolve 48 parts of epoxy resin and 15 parts of acetone, add 8 parts of dicyandiamide, and form a uniform core material solution through ultrasonic dispersion and vacuum degassing; mix 30 parts of chitosan, 70 parts of acetic acid solution and 20 parts of gelatin, adjust the pH to 5, add 0.5 parts of glutaraldehyde, stir and react for 2 hours, and obtain the wall material solution after cooling; add 3 parts of Tween-80 emulsifier to the core material solution and the wall material solution, form an emulsion through high-pressure homogenization, add 0.3 parts of CaCl2, react at 50°C for 2-3 hours, and spray dry to obtain the repair capsules.

[0028] 3. Preparation of cement mortar mixed with basalt: S1: 230 parts of basalt aggregate, 30 parts of fine aggregate, 160 parts of Portland cement, and 13 parts of steelmaking slag were dry-mixed for 3 minutes, 10 parts of polysilazane were sprayed, and stirred at 60 rpm for 3 minutes to obtain a primary mixture.

[0029] S2: Dissolve 1.5 parts of polycarboxylic acid high-performance water-reducing agent in 220 parts of water, stir at 1500rpm for 3min to obtain a polycarboxylic acid high-performance water-reducing agent solution, pour half of the polycarboxylic acid high-performance water-reducing agent solution into the primary mixture and stir for 3min, control the mixer speed at 100rpm, add expanded polystyrene, introduce nitrogen, control the flow rate at 1.0 L / min, continue stirring for 3min, add repair capsules, stir for 3min, add the remaining polycarboxylic acid high-performance water-reducing agent solution in batches, until the slurry is completely fluidized in the mixer, and obtain cement mortar mixed with basalt.

[0030] Embodiment 3:

[0031] A method for preparing cement mortar mixed with basalt, the specific process is as follows: 1. Preparation of expanded polystyrene: Add 10 parts of sodium carboxymethyl starch and 2 parts of alkylphenol polyoxyethylene ether to 120 parts of an aqueous solution containing 5 wt% of sodium alginate, and shear at 500 rpm for 20 min in a 40°C water bath to obtain a stable aqueous phase; 42 parts of styrene monomer, 1 part of azodicarbonamide, 0.1 part of ammonium persulfate, 5 parts of hexaphenoxycyclotriphosphazene and 30 parts of toluene are mixed and ultrasonically dispersed for 30 min to obtain an oil phase; the oil phase is gradually added to the aqueous phase, stirred at 800 rpm to form an emulsion, and the temperature is raised to 60°C for reaction for 25 min, 80°C for reaction for 30 min, and 90°C for reaction for 5 hours, and filtered and dried after cooling.

[0032] 2. Preparation of repair capsules: Mix and dissolve 30 parts of epoxy resin and 10 parts of acetone, add 5 parts of dicyandiamide, and form a uniform core material solution through ultrasonic dispersion and vacuum degassing; mix 20 parts of chitosan, 50 parts of acetic acid solution and 10 parts of gelatin, adjust the pH to 4-5, add 0.2 parts of glutaraldehyde, stir and react for 2 hours, and obtain the wall material solution after cooling; mix the core material solution and the wall material solution, add 2 parts of Tween-80 emulsifier, form an emulsion through high-pressure homogenization, add 0.2 parts of CaCl2, react at 55°C for 3 hours, and spray dry to obtain the repair capsules.

[0033] 3. Preparation of cement mortar mixed with basalt: S1: 250 parts of basalt aggregate, 30 parts of fine aggregate, 140 parts of Portland cement, and 12 parts of steelmaking slag were dry-mixed for 4 minutes, 7 parts of polysilazane was sprayed, and stirred at 70 rpm for 2 minutes to obtain a primary mixture.

[0034] S2: Dissolve 1.0 part of polycarboxylic acid high-performance water-reducing agent in 190 parts of water, stir at 1300rpm for 4min to obtain a polycarboxylic acid high-performance water-reducing agent solution, pour half of the polycarboxylic acid high-performance water-reducing agent solution into the primary mixture and stir for 4min, control the mixer speed at 110rpm, add expanded polystyrene, introduce nitrogen, control the flow rate at 0.5 L / min, continue stirring for 4min, add repair capsules, stir for 3min, add the remaining polycarboxylic acid high-performance water-reducing agent solution in batches, until the slurry is completely fluidized in the mixer, and obtain cement mortar mixed with basalt.

[0035] Embodiment 4:

[0036] A method for preparing cement mortar mixed with basalt, the specific process is as follows: 1. Preparation of expanded polystyrene: Add 13 parts of sodium carboxymethyl starch and 2.5 parts of alkylphenol polyoxyethylene ether to 180 parts of an aqueous solution containing 5 wt% of sodium alginate, and shear at 700 rpm for 17 min in a 45°C water bath to obtain a stable aqueous phase; mix 45 parts of styrene monomer, 2.5 parts of azodicarbonamide, 0.25 parts of ammonium persulfate, 7 parts of hexaphenoxycyclotriphosphazene and 40 parts of toluene, and ultrasonically disperse for 28 min to obtain an oil phase; gradually add the oil phase to the aqueous phase, stir at 800 rpm to form an emulsion, heat to 60°C for reaction for 27 min, 80°C for reaction for 38 min, and 90°C for reaction for 3.5 hours, and filter and dry after cooling.

[0037] 2. Preparation of repair capsules: Mix and dissolve 40 parts of epoxy resin and 12 parts of acetone, add 7 parts of dicyandiamide, and form a uniform core material solution through ultrasonic dispersion and vacuum degassing; mix 25 parts of chitosan, 60 parts of acetic acid solution and 15 parts of gelatin, adjust the pH to 4-5, add 0.4 parts of glutaraldehyde, stir and react for 2 hours, and obtain the wall material solution after cooling; mix the core material solution with the wall material solution, add 2.5 parts of Tween-80 emulsifier, form an emulsion through high-pressure homogenization, add 0.3 parts of CaCl2, react at 58°C for 2.5 hours, and spray dry to obtain the repair capsules.

[0038] 3. Preparation of cement mortar mixed with basalt: S1: 270 parts of basalt aggregate, 30 parts of fine aggregate, 150 parts of Portland cement, and 12.5 parts of steelmaking slag were dry-mixed for 5 minutes, 9 parts of polysilazane was sprayed, and stirred at 80 rpm for 3 minutes to obtain a primary mixture.

[0039] S2: Dissolve 1.3 parts of polycarboxylic acid high-performance water-reducing agent in 200 parts of water, stir at 1400rpm for 3.5min to obtain a polycarboxylic acid high-performance water-reducing agent solution, pour half of the polycarboxylic acid high-performance water-reducing agent solution into the primary mixture and stir for 4min, control the mixer speed at 105rpm, add expanded polystyrene, introduce nitrogen, control the flow rate at 0.7 L / min, continue stirring for 4min, add repair capsules, stir for 4min, add the remaining polycarboxylic acid high-performance water-reducing agent solution in batches, until the slurry is completely fluidized in the mixer, and obtain cement mortar mixed with basalt.

[0040] Comparative Example 1: A method for preparing cement mortar mixed with basalt, the specific process is as follows: 1. Preparation of repair capsules: Mix and dissolve 39 parts of epoxy resin and 12 parts of acetone, add 6 parts of dicyandiamide, and form a uniform core material solution through ultrasonic dispersion and vacuum degassing; mix 25 parts of chitosan, 65 parts of acetic acid solution and 16 parts of gelatin, adjust the pH to 4.5, add 0.4 parts of glutaraldehyde, stir and react for 2 hours, and obtain a wall material solution after cooling; add 2 parts of Tween-80 emulsifier to the core material solution and the wall material solution, form an emulsion through high-pressure homogenization, add 0.5 parts of CaCl2, react at 56°C for 2-3 hours, and spray dry to obtain a repair capsule.

[0041] 2. Preparation of cement mortar mixed with basalt: S1, dry-mix 210 parts of basalt aggregate, 30 parts of fine aggregate, 120 parts of Portland cement, and 12 parts of steelmaking slag for 4 minutes, spray 8 parts of polysilazane, and stir at 70 rpm for 2.5 minutes to obtain a primary mixture; S2. Dissolve 1.2 parts of polycarboxylic acid high-performance water-reducing agent in 180 parts of water, stir at 1200rpm for 4 minutes to obtain a polycarboxylic acid high-performance water-reducing agent solution, pour half of the polycarboxylic acid high-performance water-reducing agent solution into the primary mixture and stir for 3-5 minutes, control the mixer speed at 120rpm, add repair capsules, stir for 3 minutes, add the remaining polycarboxylic acid high-performance water-reducing agent solution in batches until the slurry is completely fluidized in the mixer to obtain cement mortar mixed with basalt.

[0042] Comparative Example 2: A method for preparing cement mortar mixed with basalt, the specific process is as follows: 1. Preparation of foam polystyrene: Add 12 parts of sodium carboxymethyl starch and 2.5 parts of alkylphenol polyoxyethylene ether to 160 parts of an aqueous solution containing 5 wt% of sodium alginate, and shear at 600 rpm for 18 minutes in a 45°C water bath to obtain a stable aqueous phase; 48 parts of styrene monomer, 2 parts of azodicarbonamide, 0.2 parts of ammonium persulfate, 6 parts of hexaphenoxycyclotriphosphazene and 38 parts of toluene are mixed and ultrasonically dispersed for 25 minutes to obtain an oil phase; the oil phase is gradually added to the aqueous phase, stirred at 800 rpm to form an emulsion, and the temperature is raised to 60°C for reaction for 28 minutes, 80°C for reaction for 35 minutes, and 90°C for reaction for 4 hours, and filtered and dried after cooling.

[0043] 2. Preparation of cement mortar mixed with basalt: S1, dry-mix 210 parts of basalt aggregate, 30 parts of fine aggregate, 120 parts of Portland cement, and 12 parts of steelmaking slag for 4 minutes, spray 8 parts of polysilazane, and stir at 70 rpm for 2.5 minutes to obtain a primary mixture; S2. Dissolve 1.2 parts of polycarboxylic acid high-performance water-reducing agent in 180 parts of water, stir at 1200rpm for 4min to obtain a polycarboxylic acid high-performance water-reducing agent solution, pour half of the polycarboxylic acid high-performance water-reducing agent solution into the primary mixture and stir for 3-5min, control the mixer speed at 120rpm, add expanded polystyrene, introduce nitrogen, control the flow rate at 0.8 L / min, continue stirring for 5min, add the remaining polycarboxylic acid high-performance water-reducing agent solution in batches, until the slurry is completely fluidized in the mixer, and obtain cement mortar mixed with basalt.

[0044] Performance testing: According to the standard "Test Method for Strength of Cement Mortar" (GB / T 17671-1999), the flexural strength and compressive strength tests of the cement mortar samples mixed with basalt prepared in Examples 1-5 and Comparative Examples 1-2 were respectively carried out after 7 days and 28 days of curing. The test results are shown in Table 1.

[0045]

[0046] High temperature fire resistance test: According to GB / T 9978-2008 "Fire resistance test method for building components", the cement mortar mixed with basalt prepared in Examples 1-5 and Comparative Examples 1-2 was built into a 100mm×100mm×100mm cubic test block. After standard curing for 28 days, 3 parallel samples were taken from each group for fire resistance test: the test block was placed in a high temperature furnace and heated to 800°C at a rate of 5°C / min and kept warm for 2 hours. After naturally cooling to room temperature, the residual compressive strength was tested using a universal testing machine with an accuracy of ±1%. According to the formula, ×100%, calculate the strength retention rate. Finally, take the average value as the test result, and the test results are shown in Table 2.

[0047]

[0048] Self-healing ability test: The cement mortar mixed with basalt prepared in Examples 1-5 and Comparative Examples 1-2 was built into a 100mm×100mm×100mm cubic test block, and a 0 crack was generated in the middle of the test block using the three-point bending method. The initial crack width was tested, and the test block was placed in a 20°C, 95% humidity environment for 7 days. The crack width after seven days was tested. The detailed results are shown in Table 3.

[0049]

[0050] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A cement mortar mixed with basalt, characterized in that: It includes the following raw materials in parts by weight: 230-300 parts of basalt aggregate; 90-160 parts of Portland cement; 11-13 parts of steelmaking slag; 6-10 parts of polysilazane; 44-56 parts of expanded polystyrene; 24-28 servings of repair capsules; 0.8-1.5 parts of polycarboxylic acid high performance water reducer; 160-220 parts of water.

2. The cement mortar mixed with basalt according to claim 1, characterized in that: The basalt aggregate is composed of basalt coarse aggregate and basalt fine aggregate. The particle size of the basalt coarse aggregate is 8-20 meshes, and the particle size of the basalt fine aggregate is 325-400 meshes.

3. The cement mortar mixed with basalt according to claim 2, characterized in that: The mass ratio of the basalt coarse aggregate to the basalt fine aggregate is 7:1 to 10:

1.

4. The cement mortar mixed with basalt according to claim 1, characterized in that: The CaO content in the steelmaking slag is 36%-40%.

5. The cement mortar mixed with basalt according to claim 1, characterized in that: The silicate cement is PO42.5 grade silicate cement.

6. The cement mortar mixed with basalt according to claim 1, characterized in that: The preparation method of the expanded polystyrene comprises the following steps: adding sodium carboxymethyl starch and alkylphenol polyoxyethylene ether to an aqueous solution containing 5wt% sodium alginate, and subjecting the mixture to high-speed shearing at 500-800rpm for 15-20min under a water bath condition of 40°C-50°C to obtain a stable aqueous phase; mixing styrene monomer, azodicarbonamide, ammonium persulfate, hexaphenoxy cyclotriphosphazene and toluene, and ultrasonically dispersing the mixture for 20-30min to obtain an oil phase; gradually adding the oil phase to the aqueous phase, maintaining stirring at 800rpm to form a uniform emulsion, heating the mixture to 60°C for reaction for 25-30min, heating the mixture to 80°C for reaction for 30-40min, and heating the mixture to 90°C for reaction for 3-5h, and washing, filtering and drying the mixture after cooling to obtain the expanded polystyrene.

7. The cement mortar mixed with basalt according to claim 1, characterized in that: The preparation method of the repair capsule comprises the following steps: mixing and dissolving epoxy resin and acetone, adding a curing agent, and performing ultrasonic dispersion and vacuum degassing to form a uniform core material solution; mixing chitosan, acetic acid solution and gelatin, adjusting the pH to 4-5, adding glutaraldehyde, stirring and reacting for 2 hours, and cooling to obtain a wall material solution; adding Tween-80 emulsifier to the core material solution and the wall material solution, performing high-pressure homogenization to form an emulsion, adding CaCl2, reacting at 55°C-60°C for 2-3 hours, and spray drying to obtain a repair capsule.

8. The cement mortar mixed with basalt according to claim 7, characterized in that: The curing agent is dicyandiamide.

9. The cement mortar mixed with basalt according to claim 1, characterized in that: The polycarboxylic acid high-performance water-reducing agent has a water content of less than 2.8% and a water reduction rate of greater than 25%.

10. The method for preparing cement mortar mixed with basalt according to any one of claims 1 to 9, characterized in that: The specific steps are as follows: S1. Dry-mix basalt aggregate, silicate cement and steelmaking slag for 3-5 minutes, spray polysilazane, and continue stirring for 2-3 minutes to obtain a primary mixture; S2. Dissolve the polycarboxylic acid high-performance water-reducing agent in water and homogenize to obtain a water-reducing agent solution. Pour half of the polycarboxylic acid high-performance water-reducing agent solution into the primary mixture and stir for 3-5 minutes. Add expanded polystyrene, introduce nitrogen, continue stirring for 3-5 minutes, add repair capsules, stir for 3-5 minutes, and add the remaining water-reducing agent solution in batches until the slurry is completely fluidized in the mixer to obtain cement mortar mixed with basalt.

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