Basalt bar and steel fiber reinforced highway cover and preparation method thereof

Abstract

The present invention discloses a basalt bar and steel fiber reinforced highway cover plate and a preparation method thereof, and relates to the technical field of engineering materials. Cement, pre-treated waste backfill solidified soil coarse aggregate, and pre-treated waste casting sand fine aggregate are added to a mixer and stirred, homemade core-shell slow-release microspheres and a dispersant are added to the mixer and stirred, a polycarboxylate water-reducing agent solution is added to the mixer three times and stirred, steel fiber and lubricant, pre-treated basalt fiber bar, and polypropylene fiber are added to the mixer in sequence and stirred to obtain a mixture, the mixture is poured into a mold, and the mold is cured and demolded to obtain a basalt bar and steel fiber reinforced highway cover plate. The basalt bar and steel fiber reinforced highway cover plate prepared by the present invention have good load-bearing capacity, impact toughness and durability, and are suitable for use in scenarios such as high-load traffic, high maintenance costs, and high-frequency chemical use sections.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering materials, in particular to a basalt bar and steel fiber reinforced highway cover plate and a preparation method thereof. Background Art

[0002] As an integral part of transportation infrastructure, highway cover plates bear the dynamic and static loads of vehicles and environmental erosion for a long time. Their durability and mechanical properties affect road safety and maintenance costs. Traditional concrete cover plates are mostly reinforced with natural aggregates and single fibers, which have problems such as insufficient crack resistance and weak interface bonding. Especially in areas where deicing salt is frequently used or industrially polluted, chloride ion penetration can easily cause internal steel fiber corrosion, resulting in degradation of structural performance. In existing technologies, although the composite reinforcement of basalt fiber and steel fiber can improve the bearing capacity, problems such as uneven fiber dispersion and poor compatibility with the matrix interface still limit its application effect. In addition, conventional admixtures mostly have short-term effects on the regulation of the hydration process and cannot achieve crack self-repair and long-term chloride ion isolation. The expansion of microcracks accelerates the intrusion of environmental media, further shortening the service life. In response to the above problems, it is urgent to develop a highway cover plate system that combines high strength and toughness, intelligent repair and green environmental protection, and break through the bottleneck of traditional technology through material innovation and process optimization. Summary of the Invention

[0003] The object of the present invention is to provide a basalt bar and steel fiber reinforced highway cover and a preparation method thereof, so as to solve the problems raised in the background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A basalt bar and steel fiber reinforced highway cover is obtained by molding and curing a mixture, wherein the mixture includes the following raw material components:

[0006] 200-300 parts of cement;

[0007] 700-900 parts of waste backfill solidified soil coarse aggregate;

[0008] 400-500 parts of discarded foundry sand fine aggregate;

[0009] 0.8-1.2 parts of basalt fiber reinforcement;

[0010] 25-30 parts of steel fiber;

[0011] 1.4-2.2 parts of polypropylene fiber;

[0012] 10-14 copies of core-shell sustained-release microspheres;

[0013] Lubricant 0.15-0.2 parts;

[0014] 1-2 parts of dispersant;

[0015] Polycarboxylate water reducer 7.4-12.6 parts;

[0016] 180-220 parts of distilled water;

[0017] Furthermore, the cement is one of P.O42.5 Portland cement, P.O42.5R Portland cement, and P.C42.5 Portland cement;

[0018] Furthermore, the waste backfill solidified soil coarse aggregate is crushed, magnetically separated to remove iron, alkali treated, and dried to a particle size of 8-20 mm;

[0019] Furthermore, the waste foundry sand fine aggregate is subjected to high temperature roasting, pickling, and screening treatments to obtain a particle size of 0.3-5 mm;

[0020] Furthermore, the surface of the basalt fiber reinforcement is sandblasted, and the length is 1300 mm and the diameter is 12 mm;

[0021] Furthermore, the steel fiber is a copper-plated steel fiber with a length of 30 mm and a diameter of 0.3 mm;

[0022] Furthermore, the polypropylene fiber has a length of 6 mm, a fineness of 15 deniers, and a melting point of 160°C;

[0023] Furthermore, the lubricant is polyethylene oxide;

[0024] Furthermore, the dispersant is at least one of hydroxypropyl methylcellulose and a silane coupling agent;

[0025] Furthermore, the preparation steps of the core-shell sustained-release microspheres are as follows:

[0026] A1. Dissolve hexadecyltrimethylammonium bromide and polyethylene glycol in a mixed solution of ammonia water and ethanol solution, adjust the pH to 12.5, ultrasonicate at 40-50°C for 20-40 min, add tetraethyl orthosilicate dropwise at a rate of 0.5-1 mL / min, and simultaneously add calcium nitrate solution dropwise at a rate of 0.2-0.4 mL / min, adjust the pH to 10.8-11, increase the temperature gradually from 40°C to 50°C, react for 24-36 h, centrifuge at 8000-10000 r / min for 10-20 min, wash with ethanol three times, and dry in supercritical CO2 at 40-50°C and 5-12 MPa for 2 h to prepare a porous SiO2 support core material;

[0027] The molecular weight of the polyethylene glycol is 200-600;

[0028] The concentration of the ammonia solution is 25-30%;

[0029] The mass fraction of ethanol in the ethanol solution is 90-95%;

[0030] The concentration of the calcium nitrate solution is 0.1-0.2 mol / L;

[0031] The usage ratio of hexadecyltrimethylammonium bromide, polyethylene glycol, ammonia water, ethanol solution, ethyl orthosilicate and calcium nitrate solution is (3-5) g: (1.5-2) g: (8-10) mL: (50-60) mL: (10-12) mL: (30-36) mL;

[0032] It should be noted that in step A1, the porous structure is regulated by combining the template agent (hexadecyltrimethylammonium bromide and polyethylene glycol) through the sol-gel method; hexadecyltrimethylammonium bromide is used as a surfactant to form a micelle template, and polyethylene glycol is used as a co-template to adjust the pore size and connectivity; tetraethyl orthosilicate is hydrolyzed and condensed under alkaline conditions to form a SiO2 network, and the Ca of calcium nitrate is used to form a silicate network. 2+ The pore wall stability is enhanced by coordination with silanol groups. Supercritical CO2 drying avoids the capillary collapse of traditional drying, thereby preserving the high specific surface area and open pore structure.

[0033] A2. Pre-react bisphenol F epoxy resin and 2-furylamine at 65°C for 2 hours, cool to 50°C, add isophorone diisocyanate and dibutyltin dilaurate, and react at 80°C under nitrogen protection for 4 hours to obtain a polyurethane shell material;

[0034] The usage ratio of the bisphenol F epoxy resin, 2-furylamine, isophorone diisocyanate and dibutyltin dilaurate is (14-16) g: (2.1-2.7) g: (5-8) g: (0.01-0.05) g;

[0035] It should be noted that in step A2, the epoxy groups of the bisphenol F epoxy resin undergo a ring-opening reaction with the primary amino groups of 2-furylamine to form a prepolymer containing secondary amines and hydroxyl groups. Isophorone diisocyanate is then added. Under the catalysis of dibutyltin dilaurate, the isocyanate groups (-NCO) of the isophorone diisocyanate react with the hydroxyl groups in the prepolymer to form polyurethane segments (-NHCOO-), while leaving unreacted epoxy and amine groups. Nitrogen protection suppresses side reactions (such as reaction of the -NCO groups with water), ultimately forming an epoxy-polyurethane copolymer shell with hydroxyl and amino active sites retained in the molecular chain.

[0036] A3. Add the porous SiO2 support core material and the polyurethane shell material to the mixed solvent, ultrasonically disperse for 30 minutes, add bismaleimide, zinc chloride and nano-kaolin, stir for 20 minutes, react at 120-150°C for 2-3 hours, and heat to 160-165°C for 1-2 hours to obtain the core-shell material;

[0037] The mixed solvent is a mixed solution of toluene and dimethyl sulfoxide in a volume ratio of 8:2;

[0038] The mixed solvent is mixed with BYK-111 wetting and dispersing agent in an amount of 0.05% by mass of the mixed solvent;

[0039] The usage ratio of the porous SiO2 support core material, the polyurethane shell material, the mixed solvent, bismaleimide, zinc chloride and nano-kaolin is (10-14) g:100 g:(300-350) mL:(0.4-0.6) g:(0.4-1.8) mg:(1.5-2.5) g;

[0040] It should be noted that in step A3, the core material is dispersed in the shell material prepolymer and uniformly coated by ultrasound; the bismaleimide reacts with the furan groups in the shell material to form a Diels-Alder reaction, forming a reversible crosslinked network, which gives the shell stress responsiveness; the nano-kaolin flakes are combined with the polymer chain segments through hydrogen bonds and physical intercalation, enhancing the mechanical strength of the shell; and the crosslinking density is gradually increased by curing in stages.

[0041] A4. The core-shell material was dispersed in a γ-glycidyloxypropyltrimethoxysilane / ethanol solution, shaken at 55°C for 6 hours, centrifuged, washed, dried, and plasma treated for 5 minutes. The core-shell material was immersed in a polyethyleneimine solution at 60°C for 2 hours, centrifuged, washed, and dried to obtain core-shell sustained-release microspheres.

[0042] The mass fraction of the ethanol solution is 95%;

[0043] The mass fraction of the polyethyleneimine solution is 5%;

[0044] The plasma treatment was carried out in an argon atmosphere with a power of 100W;

[0045] The ratio of the core-shell material, γ-glycidyloxypropyltrimethoxysilane, ethanol solution and polyethyleneimine solution is (90-110) g: (4.4-5.6) mL: (90-110) mL: (45-55) mL;

[0046] It should be noted that in step A4, the core-shell material is immersed in a γ-glycidyloxypropyltrimethoxysilane / ethanol solution, and the Si-OH generated by silane hydrolysis condenses with the hydroxyl or amino group on the shell surface to graft epoxy groups; the plasma treatment activates the surface by bombarding high-energy particles to generate free radicals and oxygen-containing groups, thereby enhancing the adsorption capacity of polyethyleneimine; the primary amino group of polyethyleneimine undergoes a ring-opening reaction with the epoxy group to form a stable covalent bond, and constructs an epoxy / amino synergistic site on the shell surface. On the one hand, its polar amino group can enhance the hydrophilicity of the microspheres, promote wetting with the cover substrate (cement paste), and increase interfacial compatibility; on the other hand, its strong cationic properties adsorb Cl through electrostatic action. - .

[0047] It should be noted again that the calcium ions coordinated by the core layer of the microspheres are gradually released in the cement environment, maintaining the supersaturation of the liquid phase, promoting the continuous hydration of tricalcium silicate and dicalcium silicate, and improving the later strength. At the same time, the exposed silica can serve as the nucleation site of the CSH gel heterogeneous phase, refining the gel network; the epoxy ring opening on the surface of the microsphere shell reacts with the deprotonated silicon oxygen bond in the high pH CSH phase to form covalent bonds and hydroxyl groups, which can further form hydrogen bonds with the non-deprotonated silicon hydroxyl groups in the CSH phase, further enhancing the interface bonding; in winter, some NaCl or CaCl2 snow-melting agents are spread on the roads, or there are residual chlorine-containing chemicals on the industrial park roads. The highway covers are exposed to the environment for a long time, and Cl - Gradually penetrates into the cover through melting or rain erosion, and accumulation to a certain extent will still cause steel rust, especially in cracks or joints. - The enrichment can be carried out, and the local concentration can exceed the critical value. When the highway cover prepared by the present invention is actually put into use, the microspheres rupture under stress to release calcium ions to repair cracks. The released calcium ions and chloride ions are fixed by Friedel salt, which reduces the diffusion coefficient of chloride ions and inhibits steel corrosion.

[0048] A method for preparing a basalt bar and steel fiber reinforced highway cover comprises the following steps:

[0049] S1. Weigh each raw material according to the above parts by weight;

[0050] S2. Start the mixer at a speed of 30-40 r / min, add cement, waste backfill solidified soil coarse aggregate, and waste foundry sand fine aggregate into the mixer, and stir for 3-5 minutes;

[0051] S3. Add the core-shell sustained-release microspheres and dispersant into a blender and stir for 15-25 minutes;

[0052] S4. Dissolve the polycarboxylate water reducer in distilled water to prepare a water reducer solution, and add it to the mixer at a speed of 60-80 r / min three times, stirring for 1-2 minutes each time, with an interval of 1-2 minutes between each time;

[0053] S5. Reduce the mixer speed to 30-40 r / min, add steel fiber and lubricant into the mixer, and stir for 2-3 minutes; add basalt fiber reinforcement and stir for 3-5 minutes; add polypropylene fiber and stir for 1-2 minutes. The mixer is equipped with a cooling interlayer and the stirring temperature is controlled to be less than 35°C during the stirring period.

[0054] S6. Pour the mixture into the mold, vibrate and compact it for 2-3 minutes, cover the surface with polyethylene film, let it stand for 1 hour, apply 0.8MPa pressure and maintain the pressure for 8-10 minutes, steam cure at a temperature of 60℃ and a humidity of 95% for 24-48 hours, cool it naturally to room temperature, remove the mold, and obtain the basalt rib and steel fiber reinforced highway cover.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The basalt bar and steel fiber reinforced highway cover prepared by the present invention has excellent mechanical properties and long-term durability. Through the synergistic reinforcement of basalt bar and steel fiber, the bending resistance and impact toughness are significantly improved; the core-shell slow-release microspheres control the release of calcium ions during long-term use through alkaline environmental characteristics and stress response characteristics, promote the continuous hydration of the cover matrix and induce the dense growth of CSH phase gel, realize microcrack self-repair and chloride ion directional solidification, and extend the service life. The surface functional group modification is highly compatible with the matrix and effectively inhibits the penetration and diffusion of chloride ions; waste backfill soil and molding sand are used as aggregates, which reduces the environmental burden while ensuring high bearing capacity, reduces cement use, and reduces costs and increases efficiency. DETAILED DESCRIPTION

[0057] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0058] (1) The coarse aggregate of the waste backfill solidified soil was crushed (jaw crusher, feed size ≤ 300 mm, discharge size 8-20 mm, power 45 kW), magnetically separated and iron removed (permanent magnetic drum magnetic separator, magnetic field strength ≥ 1500 gauss, processing capacity 20 t / h), alkali treated (soaked in 5% NaOH solution for 24 h, liquid-to-solid ratio 3:1), and dried (rotary drying kiln, temperature 150 ± 10 °C, time 2 h);

[0059] (2) The waste foundry sand fine aggregate was processed by high temperature roasting (800℃ roasting for 2h in a muffle furnace), pickling (10% HCl solution with stirring for 30min, neutralization with sodium carbonate solution to neutral pH, and rinsing with deionized water three times), and screening (double-layer vibrating screen, upper layer 5mm / lower layer 0.3mm, stainless steel mesh, amplitude 3mm);

[0060] (3) The surface of basalt fiber reinforcement with a length of 1300 mm and a diameter of 12 mm was treated by sandblasting (corundum, particle size 0.5-1 mm, air pressure 0.6 MPa, spray angle 75°, roughness Ra 12.5 μm);

[0061] (4) Copper-coated steel fiber length 30 mm, diameter 0.3 mm;

[0062] (5) Polypropylene fiber length: 6 mm, fineness: 15 denier, melting point: 160°C;

[0063] (6) The preparation steps of core-shell sustained-release microspheres are as follows:

[0064] A1. Dissolve 20 g of hexadecyltrimethylammonium bromide and 8.8 g of polyethylene glycol (molecular weight 400) in a mixed solution of 46 mL of 30% ammonia water and 272.5 mL of 95% ethanol solution, adjust the pH to 12.5, and ultrasonicate at 45°C for 30 min. Add 54 mL of ethyl orthosilicate dropwise at a rate of 0.8 mL / min, and simultaneously add 167 mL of 0.2 mol / L calcium nitrate solution dropwise at a rate of 0.3 mL / min, adjust the pH to 10.8, increase the temperature gradually from 40°C to 50°C, react for 24 h, centrifuge at 8000 r / min for 15 min, wash with ethanol three times, and dry in supercritical CO2 at 45°C and 10 MPa for 2 h to prepare a porous SiO2 support core material.

[0065] A2. Pre-react 150 g of bisphenol F epoxy resin and 24 g of 2-furylamine at 65 ° C for 2 h, cool to 50 ° C, add 65 g of isophorone diisocyanate and 0.3 g of dibutyltin dilaurate, and react at 80 ° C under nitrogen protection for 4 h to obtain a polyurethane shell material;

[0066] A3. 12 g of porous SiO2 support core material and 100 g of polyurethane shell material were added to a mixed solution of 325 mL of toluene and dimethyl sulfoxide (DMSO) with a volume ratio of 8:2 and 0.13 g of BYK-111 wetting and dispersing agent, and ultrasonically dispersed for 30 min. 0.5 g of bismaleimide, 1 mg of zinc chloride, and 2 g of nano-kaolin were added, stirred for 20 min, reacted at 140 ° C for 2 h, and then heated to 160 ° C for 2 h to obtain a core-shell material.

[0067] A4. Disperse 100 g of core-shell material in a mixed solution of 5 mL of γ-glycidyloxypropyltrimethoxysilane and 100 mL of 95% ethanol solution, shake at 55°C for 6 h, centrifuge, wash, dry, and plasma treat for 5 min in an argon atmosphere at a power of 100 W. Immerse in 50 mL of 5% polyethyleneimine solution at 60°C for 2 h, centrifuge, wash, and dry to obtain core-shell sustained-release microspheres.

[0068] Example 1, a basalt bar and steel fiber reinforced highway cover plate is obtained by molding and curing a mixture, wherein the mixture comprises the following raw material components:

[0069] 250 parts of P.O42.5R Portland cement;

[0070] 800 parts of waste backfill solidified soil coarse aggregate;

[0071] 450 parts of discarded foundry sand fine aggregate;

[0072] 1 part of basalt fiber reinforcement;

[0073] 27.5 parts of copper-coated steel fiber;

[0074] 1.8 parts of polypropylene fiber;

[0075] 12 servings of core-shell sustained-release microspheres;

[0076] 0.18 parts of polyethylene oxide;

[0077] 1.5 parts of hydroxypropyl methylcellulose;

[0078] 10 parts of polycarboxylate water reducer;

[0079] 200 parts of distilled water;

[0080] A method for preparing a basalt bar and steel fiber reinforced highway cover comprises the following steps:

[0081] S1. Weigh each raw material according to the above parts by weight;

[0082] S2. Start the mixer at a speed of 30 r / min, add cement, waste backfill solidified soil coarse aggregate and waste foundry sand fine aggregate into the mixer, and stir for 5 minutes;

[0083] S3. Add the core-shell sustained-release microspheres and hydroxypropyl methylcellulose into a blender and stir for 20 minutes;

[0084] S4. Dissolve the polycarboxylate water reducer in distilled water to prepare a water reducer solution, and add it to the mixer at a speed of 60 r / min three times, stirring for 2 minutes each time, with an interval of 1 minute between each time;

[0085] S5. Reduce the mixer speed to 40 r / min, add copper-coated steel fiber and polyethylene oxide into the mixer and stir for 3 minutes; add basalt fiber reinforcement and stir for 5 minutes; add polypropylene fiber and stir for 1 minute. The mixer is equipped with a cooling interlayer and the stirring temperature is controlled to be less than 35°C during the stirring period;

[0086] S6. Pour the mixture into the mold, vibrate and compact for 3 minutes, cover the surface with polyethylene film, let it stand for 1 hour, apply 0.8 MPa pressure and maintain the pressure for 10 minutes, steam cure at a temperature of 60°C and a humidity of 95% for 36 hours, cool naturally to room temperature, remove the mold, and obtain basalt bars and steel fiber reinforced highway cover.

[0087] Example 2, a basalt bar and steel fiber reinforced highway cover plate, obtained by molding and curing a mixture, wherein the mixture comprises the following raw material components:

[0088] 200 parts of P.O42.5R Portland cement;

[0089] 700 parts of waste backfill solidified soil coarse aggregate;

[0090] 400 parts of discarded foundry sand fine aggregate;

[0091] 0.8 parts of basalt fiber reinforcement;

[0092] 25 parts of copper-plated steel fiber;

[0093] 1.4 parts of polypropylene fiber;

[0094] 10 core-shell sustained-release microspheres;

[0095] 0.15 parts of polyethylene oxide;

[0096] 1 part of hydroxypropyl methylcellulose;

[0097] 7.4 parts of polycarboxylate water reducer;

[0098] 180 parts of distilled water;

[0099] A method for preparing a basalt bar and steel fiber reinforced highway cover comprises the following steps:

[0100] S1. Weigh each raw material according to the above parts by weight;

[0101] S2. Start the mixer at a speed of 30 r / min, add cement, waste backfill solidified soil coarse aggregate and waste foundry sand fine aggregate into the mixer, and stir for 5 minutes;

[0102] S3. Add the core-shell sustained-release microspheres and hydroxypropyl methylcellulose into a blender and stir for 20 minutes;

[0103] S4. Dissolve the polycarboxylate water reducer in distilled water to prepare a water reducer solution, and add it to the mixer at a speed of 60 r / min three times, stirring for 2 minutes each time, with an interval of 1 minute between each time;

[0104] S5. Reduce the mixer speed to 40 r / min, add copper-coated steel fiber and polyethylene oxide into the mixer and stir for 3 minutes; add basalt fiber reinforcement and stir for 5 minutes; add polypropylene fiber and stir for 1 minute. The mixer is equipped with a cooling interlayer and the stirring temperature is controlled to be less than 35°C during the stirring period;

[0105] S6. Pour the mixture into the mold, vibrate and compact for 3 minutes, cover the surface with polyethylene film, let it stand for 1 hour, apply 0.8 MPa pressure and maintain the pressure for 10 minutes, steam cure at a temperature of 60°C and a humidity of 95% for 36 hours, cool naturally to room temperature, remove the mold, and obtain basalt bars and steel fiber reinforced highway cover.

[0106] Example 3, a basalt bar and steel fiber reinforced highway cover plate is obtained by molding and curing a mixture, wherein the mixture comprises the following raw material components:

[0107] 300 parts of P.O42.5R Portland cement;

[0108] 900 parts of waste backfill solidified soil coarse aggregate;

[0109] 500 parts of discarded foundry sand fine aggregate;

[0110] 1.2 parts of basalt fiber reinforcement;

[0111] 30 parts of copper-plated steel fiber;

[0112] 2.2 parts of polypropylene fiber;

[0113] 14 core-shell sustained-release microspheres;

[0114] 0.2 parts of polyethylene oxide;

[0115] 2 parts of hydroxypropyl methylcellulose;

[0116] 12.6 parts of polycarboxylate water reducer;

[0117] 220 parts of distilled water;

[0118] A method for preparing a basalt bar and steel fiber reinforced highway cover comprises the following steps:

[0119] S1. Weigh each raw material according to the above parts by weight;

[0120] S2. Start the mixer at a speed of 30 r / min, add cement, waste backfill solidified soil coarse aggregate and waste foundry sand fine aggregate into the mixer, and stir for 5 minutes;

[0121] S3. Add the core-shell sustained-release microspheres and hydroxypropyl methylcellulose into a blender and stir for 20 minutes;

[0122] S4. Dissolve the polycarboxylate water reducer in distilled water to prepare a water reducer solution, and add it to the mixer at a speed of 60 r / min three times, stirring for 2 minutes each time, with an interval of 1 minute between each time;

[0123] S5. Reduce the mixer speed to 40 r / min, add copper-coated steel fiber and polyethylene oxide into the mixer and stir for 3 minutes; add basalt fiber reinforcement and stir for 5 minutes; add polypropylene fiber and stir for 1 minute. The mixer is equipped with a cooling interlayer and the stirring temperature is controlled to be less than 35°C during the stirring period;

[0124] S6. Pour the mixture into the mold, vibrate and compact for 3 minutes, cover the surface with polyethylene film, let it stand for 1 hour, apply 0.8 MPa pressure and maintain the pressure for 10 minutes, steam cure at a temperature of 60°C and a humidity of 95% for 36 hours, cool naturally to room temperature, remove the mold, and obtain basalt bars and steel fiber reinforced highway cover.

[0125] Comparative Example 1:

[0126] A basalt bar and steel fiber reinforced highway cover is obtained by molding and curing a mixture, wherein the mixture includes the following raw material components:

[0127] 250 parts of P.O42.5R Portland cement;

[0128] 800 parts of waste backfill solidified soil coarse aggregate;

[0129] 450 parts of discarded foundry sand fine aggregate;

[0130] 1 part of basalt fiber reinforcement;

[0131] 27.5 parts of copper-coated steel fiber;

[0132] 1.8 parts of polypropylene fiber;

[0133] 12 parts of quartz sand (10-20 mesh);

[0134] 0.18 parts of polyethylene oxide;

[0135] 1.5 parts of hydroxypropyl methylcellulose;

[0136] 10 parts of polycarboxylate water reducer;

[0137] 200 parts of distilled water;

[0138] A method for preparing a basalt bar and steel fiber reinforced highway cover comprises the following steps:

[0139] S1. Weigh each raw material according to the above parts by weight;

[0140] S2. Start the mixer at a speed of 30 r / min, add cement, waste backfill solidified soil coarse aggregate and waste foundry sand fine aggregate into the mixer, and stir for 5 minutes;

[0141] S3, add quartz sand and hydroxypropyl methylcellulose into the blender and stir for 20 minutes;

[0142] S4. Dissolve the polycarboxylate water reducer in distilled water to prepare a water reducer solution, and add it to the mixer at a speed of 60 r / min three times, stirring for 2 minutes each time, with an interval of 1 minute between each time;

[0143] S5. Reduce the mixer speed to 40 r / min, add copper-coated steel fiber and polyethylene oxide into the mixer and stir for 3 minutes; add basalt fiber reinforcement and stir for 5 minutes; add polypropylene fiber and stir for 1 minute. The mixer is equipped with a cooling interlayer and the stirring temperature is controlled to be less than 35°C during the stirring period;

[0144] S6. Pour the mixture into the mold, vibrate and compact for 3 minutes, cover the surface with polyethylene film, let it stand for 1 hour, apply 0.8 MPa pressure and maintain the pressure for 10 minutes, steam cure at a temperature of 60°C and a humidity of 95% for 36 hours, cool naturally to room temperature, remove the mold, and obtain basalt bars and steel fiber reinforced highway cover.

[0145] The difference between this comparative example and Example 1 is that quartz sand is added instead of core-shell sustained-release microspheres.

[0146] Comparative Example 2:

[0147] A basalt bar and steel fiber reinforced highway cover is obtained by molding and curing a mixture, wherein the mixture includes the following raw material components:

[0148] 250 parts of P.O42.5R Portland cement;

[0149] 800 parts of waste backfill solidified soil coarse aggregate;

[0150] 450 parts of discarded foundry sand fine aggregate;

[0151] 1 part of basalt fiber reinforcement;

[0152] 27.5 parts of copper-coated steel fiber;

[0153] 1.8 parts of polypropylene fiber;

[0154] 12 parts of core-shell composite material;

[0155] 0.18 parts of polyethylene oxide;

[0156] 1.5 parts of hydroxypropyl methylcellulose;

[0157] 10 parts of polycarboxylate water reducer;

[0158] 200 parts of distilled water;

[0159] The preparation steps of the core-shell material are as follows:

[0160] B1. Pre-react 150 g of bisphenol F epoxy resin and 24 g of 2-furylamine at 65 ° C for 2 h, cool to 50 ° C, add 65 g of isophorone diisocyanate and 0.3 g of dibutyltin dilaurate, and react at 80 ° C under nitrogen protection for 4 h to obtain a polyurethane shell material;

[0161] B2, 12g of commercially available SiO2 and 100g of polyurethane shell material were added to 325mL of mixed solvent mixed with 0.13g of BYK-111 wetting and dispersing agent, and ultrasonically dispersed for 30min, 0.5g of bismaleimide and 2g of nano-kaolin were added, stirred for 20min, reacted at 140°C for 2h, and then heated to 160°C for 2h to obtain a core-shell material;

[0162] A method for preparing a basalt bar and steel fiber reinforced highway cover comprises the following steps:

[0163] S1. Weigh each raw material according to the above parts by weight;

[0164] S2. Start the mixer at a speed of 30 r / min, add cement, waste backfill solidified soil coarse aggregate and waste foundry sand fine aggregate into the mixer, and stir for 5 minutes;

[0165] S3, adding the core-shell material and hydroxypropyl methylcellulose into a blender and stirring for 20 minutes;

[0166] S4. Dissolve the polycarboxylate water reducer in distilled water to prepare a water reducer solution, and add it to the mixer at a speed of 60 r / min three times, stirring for 2 minutes each time, with an interval of 1 minute between each time;

[0167] S5. Reduce the mixer speed to 40 r / min, add copper-coated steel fiber and polyethylene oxide into the mixer and stir for 3 minutes; add basalt fiber reinforcement and stir for 5 minutes; add polypropylene fiber and stir for 1 minute. The mixer is equipped with a cooling interlayer and the stirring temperature is controlled to be less than 35°C during the stirring period;

[0168] S6. Pour the mixture into the mold, vibrate and compact for 3 minutes, cover the surface with polyethylene film, let it stand for 1 hour, apply 0.8 MPa pressure and maintain the pressure for 10 minutes, steam cure at a temperature of 60°C and a humidity of 95% for 36 hours, cool naturally to room temperature, remove the mold, and obtain basalt bars and steel fiber reinforced highway cover.

[0169] The difference between this comparative example and Example 1 is that core-shell material is added instead of core-shell sustained-release microspheres.

[0170] Comparative Example 3:

[0171] A basalt bar and steel fiber reinforced highway cover is obtained by molding and curing a mixture, wherein the mixture includes the following raw material components:

[0172] 250 parts of P.O42.5R Portland cement;

[0173] 800 parts of waste backfill solidified soil coarse aggregate;

[0174] 450 parts of discarded foundry sand fine aggregate;

[0175] 1 part of basalt fiber reinforcement;

[0176] 27.5 parts of copper-coated steel fiber;

[0177] 1.8 parts of polypropylene fiber;

[0178] 12 parts of porous SiO2 support;

[0179] 0.18 parts of polyethylene oxide;

[0180] 1.5 parts of hydroxypropyl methylcellulose;

[0181] 10 parts of polycarboxylate water reducer;

[0182] 200 parts of distilled water;

[0183] The preparation steps of the porous SiO2 support are as follows:

[0184] 20 g of hexadecyltrimethylammonium bromide and 8.8 g of polyethylene glycol (molecular weight 400) were dissolved in a mixed solution of 46 mL of 30% ammonia water and 272.5 mL of 95% ethanol solution, the pH was adjusted to 12.5, and ultrasonic treatment was performed at 45°C for 30 min. 54 mL of tetraethyl orthosilicate was added dropwise at a rate of 0.8 mL / min, and 167 mL of 0.2 mol / L calcium nitrate solution was added dropwise at a rate of 0.3 mL / min. The pH was adjusted to 10.8, and the temperature was gradually increased from 40°C to 50°C for 24 h. The mixture was centrifuged at 8000 r / min for 15 min, washed with ethanol three times, and dried in supercritical CO2 at 45°C and 10 MPa for 2 h to prepare a porous SiO2 support.

[0185] A method for preparing a basalt bar and steel fiber reinforced highway cover comprises the following steps:

[0186] S1. Weigh each raw material according to the above parts by weight;

[0187] S2. Start the mixer at a speed of 30 r / min, add cement, waste backfill solidified soil coarse aggregate and waste foundry sand fine aggregate into the mixer, and stir for 5 minutes;

[0188] S3, adding the porous SiO2 support and hydroxypropyl methylcellulose into a blender and stirring for 20 minutes;

[0189] S4. Dissolve the polycarboxylate water reducer in distilled water to prepare a water reducer solution, and add it to the mixer at a speed of 60 r / min three times, stirring for 2 minutes each time, with an interval of 1 minute between each time;

[0190] S5. Reduce the mixer speed to 40 r / min, add copper-coated steel fiber and polyethylene oxide into the mixer and stir for 3 minutes; add basalt fiber reinforcement and stir for 5 minutes; add polypropylene fiber and stir for 1 minute. The mixer is equipped with a cooling interlayer and the stirring temperature is controlled to be less than 35°C during the stirring period;

[0191] S6. Pour the mixture into the mold, vibrate and compact for 3 minutes, cover the surface with polyethylene film, let it stand for 1 hour, apply 0.8 MPa pressure and maintain the pressure for 10 minutes, steam cure at a temperature of 60°C and a humidity of 95% for 36 hours, cool naturally to room temperature, remove the mold, and obtain basalt bars and steel fiber reinforced highway cover.

[0192] The difference between this comparative example and Example 1 is that core-shell sustained-release microspheres are not added, but porous SiO2 support is added.

[0193] test:

[0194] 1. Crack load

[0195] Specimen size: 600mm x 600mm x 20mm cuboid. Test method referenced China Southern Power Grid's "Standard Technical Specification for Cable Trench Covers."

[0196] 2. Destruction load

[0197] Sample size: 600mm × 600mm × 20mm. Test method refers to the China Southern Power Grid's "Standard Technical Bid for Cable Trench Covers."

[0198] 3. Impact resistance

[0199] Specimen size: 600mm×600mm×20mm. Place the specimen horizontally with simple supports on both sides, with a clear span of 65cm. A 5kg steel ball is dropped from a height of 1.5m and impacts the cement cover plate multiple times without breaking.

[0200] 4. Chloride ion diffusion coefficient

[0201] Specimen size: Φ100×50mm cylinder. Test method reference GB / T 50082-2024 Standard for Test Methods of Long-term Properties and Durability of Ordinary Concrete.

[0202] 5. Wear resistance (mass loss rate)

[0203] Sample size: 100mm × 100mm × 20mm. Test method: GB / T 16925 Test method for abrasion resistance of concrete and its products (ball bearing method).

[0204] 6. Results Summary

[0205] Table 1

[0206]

[0207] It can be seen from Table 1 that the highway cover plate samples prepared in Examples 1-3 have good load-bearing capacity, impact toughness and durability compared with Comparative Examples 1-3, and are suitable for use in scenarios such as high-load traffic, high maintenance costs and high-frequency chemical use sections.

[0208] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0209] 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 described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A basalt bar and steel fiber reinforced highway cover plate, obtained by molding and curing a mixture, characterized by: The mixture comprises the following raw material components: 200-300 parts of cement; 700-900 parts of waste backfill solidified soil coarse aggregate; 400-500 parts of discarded foundry sand fine aggregate; 0.8-1.2 parts of basalt fiber reinforcement; 25-30 parts of steel fiber; 1.4-2.2 parts of polypropylene fiber; 10-14 copies of core-shell sustained-release microspheres; Lubricant 0.15-0.2 parts; 1-2 parts of dispersant; Polycarboxylate water reducer 7.4-12.6 parts; 180-220 parts of distilled water; The preparation steps of the core-shell sustained-release microspheres are as follows: A1. Dissolve hexadecyltrimethylammonium bromide and polyethylene glycol in a mixed solution of ammonia water and ethanol solution, adjust the pH to 12.5, ultrasonicate at 40-50°C for 20-40 min, add tetraethyl orthosilicate dropwise at a rate of 0.5-1 mL / min, and simultaneously add calcium nitrate solution dropwise at a rate of 0.2-0.4 mL / min, adjust the pH to 10.8-11, increase the temperature gradually from 40°C to 50°C, react for 24-36 h, centrifuge at 8000-10000 r / min for 10-20 min, wash with ethanol three times, and dry in supercritical CO2 at 40-50°C and 5-12 MPa for 2 h to prepare a porous SiO2 support core material; The usage ratio of hexadecyltrimethylammonium bromide, polyethylene glycol, ammonia water, ethanol solution, ethyl orthosilicate and calcium nitrate solution is (3-5) g: (1.5-2) g: (8-10) mL: (50-60) mL: (10-12) mL: (30-36) mL; A2. Pre-react bisphenol F epoxy resin and 2-furylamine at 65°C for 2 hours, cool to 50°C, add isophorone diisocyanate and dibutyltin dilaurate, and react at 80°C under nitrogen protection for 4 hours to obtain a polyurethane shell material; The usage ratio of the bisphenol F epoxy resin, 2-furylamine, isophorone diisocyanate and dibutyltin dilaurate is (14-16) g: (2.1-2.7) g: (5-8) g: (0.01-0.05) g; A3. Add the porous SiO2 support core material and the polyurethane shell material to the mixed solvent, ultrasonically disperse for 30 minutes, add bismaleimide, zinc chloride and nano-kaolin, stir for 20 minutes, react at 120-150°C for 2-3 hours, and heat to 160-165°C for 1-2 hours to obtain the core-shell material; The usage ratio of the porous SiO2 support core material, the polyurethane shell material, the mixed solvent, bismaleimide, zinc chloride and nano-kaolin is (10-14) g:100 g:(300-350) mL:(0.4-0.6) g:(0.4-1.8) mg:(1.5-2.5) g; A4. The core-shell material was dispersed in a γ-glycidyloxypropyltrimethoxysilane / ethanol solution, shaken at 55°C for 6 hours, centrifuged, washed, dried, and plasma treated for 5 minutes. The core-shell material was immersed in a polyethyleneimine solution at 60°C for 2 hours, centrifuged, washed, and dried to obtain core-shell sustained-release microspheres. The usage ratio of the core-shell material, gamma-glycidyloxypropyltrimethoxysilane, ethanol solution and polyethyleneimine solution is (90-110) g: (4.4-5.6) mL: (90-110) mL: (45-55) mL.

2. The basalt bar and steel fiber reinforced highway cover according to claim 1, characterized in that: The waste backfill solidified soil coarse aggregate is crushed, magnetically separated to remove iron, alkali treated, and dried to have a particle size of 8-20 mm.

3. The basalt bar and steel fiber reinforced highway cover according to claim 1, characterized in that: The waste foundry sand fine aggregate is processed by high-temperature roasting, pickling and screening, and has a particle size of 0.3-5 mm.

4. The basalt bar and steel fiber reinforced highway cover according to claim 1, characterized in that: The surface of the basalt fiber reinforcement is sandblasted, and the length is 1300 mm and the diameter is 12 mm.

5. The basalt bar and steel fiber reinforced highway cover according to claim 1, characterized in that: The steel fiber is a copper-plated steel fiber with a length of 30 mm and a diameter of 0.3 mm.

6. The basalt bar and steel fiber reinforced highway cover according to claim 1, characterized in that: The polypropylene fiber has a length of 6 mm, a fineness of 15 deniers, and a melting point of 160°C.

7. The basalt bar and steel fiber reinforced highway cover according to claim 1, characterized in that: The lubricant is polyethylene oxide.

8. The basalt bar and steel fiber reinforced highway cover according to claim 1, characterized in that: The dispersant is at least one of hydroxypropyl methylcellulose and a silane coupling agent.

9. The basalt bar and steel fiber reinforced highway cover according to claim 1, characterized in that: In step A1, the molecular weight of the polyethylene glycol is 200-600, the concentration of the ammonia water is 25-30%, the mass fraction of ethanol in the ethanol solution is 90-95%, and the concentration of the calcium nitrate solution is 0.1-0.2 mol / L; in step A3, the mixed solvent is a mixed solution of toluene and dimethyl sulfoxide in a volume ratio of 8:2, and the mixed solvent contains 0.05% of BYK-111 wetting and dispersing agent by mass of the mixed solvent; in step A4, the mass fraction of the ethanol solution is 95%, the mass fraction of the polyethyleneimine solution is 5%, and the plasma treatment is performed in an argon atmosphere at a power of 100 W.

10. A method for preparing the basalt bar and steel fiber reinforced highway cover according to any one of claims 1 to 9, characterized in that: S1. Weigh each raw material according to the above parts by weight; S2. Start the mixer at a speed of 30-40 r / min, add cement, waste backfill solidified soil coarse aggregate, and waste foundry sand fine aggregate into the mixer, and stir for 3-5 minutes; S3. Add the core-shell sustained-release microspheres and dispersant into a blender and stir for 15-25 minutes; S4. Dissolve the polycarboxylate water reducer in distilled water to prepare a water reducer solution, and add it to the mixer at a speed of 60-80 r / min three times, stirring for 1-2 minutes each time, with an interval of 1-2 minutes between each time; S5. Reduce the mixer speed to 30-40 r / min, add steel fiber and lubricant into the mixer, and stir for 2-3 minutes; add basalt fiber reinforcement and stir for 3-5 minutes; add polypropylene fiber and stir for 1-2 minutes. The mixer is equipped with a cooling interlayer and the stirring temperature is controlled to be less than 35°C during the stirring period. S6. Pour the mixture into the mold, vibrate and compact it for 2-3 minutes, cover the surface with polyethylene film, let it stand for 1 hour, apply 0.8MPa pressure and maintain the pressure for 8-10 minutes, steam cure at a temperature of 60℃ and a humidity of 95% for 24-48 hours, cool it naturally to room temperature, remove the mold, and obtain the basalt rib and steel fiber reinforced highway cover.

Images