Permeable concrete for garden road and construction method

Abstract

The invention discloses pervious concrete for garden roads and a construction method, and belongs to the technical field of concrete. The concrete is prepared from the following raw materials in parts by weight: 100-150 parts of cement, 300-360 parts of coarse aggregate, 80-100 parts of fine aggregate, 3-4 parts of a modified fiber reinforcing agent, 15-25 parts of silica fume, 20-30 parts of slag powder, 2-3 parts of a polycarboxylate superplasticizer, 0.1-0.2 part of a nano composite air entraining agent and 220-240 parts of water. According to the concrete, the proportion of the raw materials is reasonably designed, the pore structure is optimized, and the specific modified fiber reinforcing agent is added, so that the pervious concrete has the characteristics of excellent strength, freezing and thawing resistance and fertilizer corrosion resistance while keeping good pervious rate, and has a good market application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete, and in particular relates to permeable concrete for garden roads and a construction method thereof. Background Art

[0002] Permeable concrete (also known as porous concrete or sandless concrete) is a porous structural material made by mixing coarse aggregate, a binder (such as cement), water, and admixtures in specific proportions, with no or only a small amount of fine aggregate added. Point contact between the aggregates creates a large number of interconnected pores (typically with a porosity of 15%-30%), allowing rainwater to quickly penetrate the ground, combining load-bearing capacity with ecological benefits. Due to its unique permeability, permeable concrete is widely used in the following scenarios: sponge city construction, landscape engineering, municipal infrastructure, and some special scenarios such as flood control dams and slope protection projects to enhance soil stability and promote water circulation; sports venues (such as permeable plastic running track bases) to improve drainage efficiency and safety.

[0003] Permeable concrete can effectively alleviate local waterlogging and waterlogging problems in cities, and when combined with urban rainwater recycling systems, it can achieve the secondary reuse of natural water resources. Therefore, permeable concrete is increasingly used in garden landscapes and garden roads. With its widespread application, the corresponding permeable concrete has also exposed more and more problems during the use of garden roads. For example, at present, permeable concrete has good permeability, but it is difficult to ensure high mechanical properties and is prone to early damage. In cold areas, water penetrates into the pores and freezes and expands, which may cause cracking of the concrete and poor freeze-thaw resistance. Chemical substances such as fertilizers and pesticides used in gardens may corrode cementitious materials, shorten the service life of roads, and have poor resistance to chemical erosion. Therefore, it is urgent to study permeable concrete materials with high strength, good freeze-thaw resistance, and high durability while ensuring permeability. Summary of the Invention

[0004] The purpose of the present invention is to provide a permeable concrete for garden roads. By rationally designing the ratio of raw materials, optimizing the pore structure, and adding a specific modified fiber reinforcement, the permeable concrete can maintain good permeability while also having excellent strength, freeze-thaw resistance, and fertilizer corrosion resistance.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is: A permeable concrete for a garden road is prepared from the following raw materials in parts by weight: 100-150 parts of cement, 300-360 parts of coarse aggregate, 80-100 parts of fine aggregate, 3-4 parts of a modified fiber reinforcing agent, 15-25 parts of silica fume, 20-30 parts of slag powder, 2-3 parts of a polycarboxylic acid water reducer, 0.1-0.2 parts of a nano-composite air entraining agent, and 220-240 parts of water.

[0006] Preferably, the modified fiber reinforcement is prepared by the following method: A, polypropylene imitation steel fiber and carbon nanotubes were mixed according to the mass ratio and activated by argon plasma for 20 minutes; B, the activated product was immersed in 5% KH-570 ethanol solution, reacted at 60℃ for 2-3h, and dried at 80℃ for 1h after the reaction to obtain a pretreated fiber mixture; C, deionized water, NaOH, and m-diphenol were mixed in proportion and magnetically stirred until transparent. Glutaraldehyde solution was slowly added dropwise at room temperature. After the addition, magnetic stirring was continued for 2 hours. Then, butylpyrrolidone latex was added and stirred at 600 rpm for 10 minutes until uniform. Then, 25% ammonia water was added dropwise and the pH was adjusted to 8.5 to obtain an emulsion; D. Immerse the pretreated fiber mixture obtained in step B into the emulsion obtained in step C, stir magnetically at 40° C. for 10 minutes, take it out, and dry it at 80° C. for 1 hour to obtain the modified fiber reinforcement.

[0007] Preferably, in step A, the mass ratio of polypropylene imitation steel fiber to carbon nanotube is 10:1; and the argon plasma activation conditions are 10 kV, 50 kHz.

[0008] Preferably, in step C, the mass ratio of deionized water, NaOH, m-diphenol, 50% glutaraldehyde solution, and butylpyrrolidone latex is 600:0.2:1:0.6:7; and the solid content of the butylpyrrolidone latex is 40%.

[0009] Preferably, the preparation method of the nanocomposite air entraining agent is: (1) Dispersing nano-silica in 10% ethanol, ultrasonically treating for 30-40 min, then adding silane coupling agent, stirring at 70 ° C for 4 h, centrifuging and washing 3 times, and vacuum drying to obtain pretreated nano-silica; (2) Add nanocellulose to deionized water and homogenize under high pressure to form a 1 wt% transparent gel solution; (3) The gel solution obtained in step (2) and the pretreated nano-silica obtained in step (1) were mixed according to a mass ratio, dispersed by ultrasonic at 40 kHz for 1 hour, and then allowed to stand and age for 24 hours to obtain a composite gel material; (4) The composite gel material was diluted to a solid content of 0.5 wt%, and then the pH was adjusted to 9.0 with NaOH solution to obtain a nanocomposite air entraining agent.

[0010] Preferably, the silane coupling agent in step (1) is KH570, and the mass ratio of nano-silica to KH570 is 3:1.

[0011] Preferably, in step (3), the mass ratio of the gel solution to the pretreated nano-silica is 10:3.

[0012] Preferably, the coarse aggregate is basalt crushed stone, wherein the mass ratio of coarse aggregate with particle size of 15-20 mm and 10-15 mm is 2:5; the fine aggregate is river sand, wherein the mass ratio of fine aggregate with particle size of 2-3 mm and 3.5-4.5 mm is 3:7.

[0013] The present invention also provides a construction method for permeable concrete for garden roads, comprising the following steps: Step 1, mixing coarse aggregate and fine aggregate according to the required particle size ratio; Step 2: Prepare a modified fiber reinforcement, and put it into a mixer with coarse aggregate and fine aggregate for dry mixing; Step 3: Continue adding cement, silica fume, slag powder, and polycarboxylate water reducer into the mixer and continue stirring for 3-5 minutes to form a uniform mixture; Step 4: add 80% of the total water into the mixer, stir at 60 rpm for 1-2 minutes, then add the mixture consisting of the nano-composite air-entraining agent and the remaining 20% ​​of water, stir at 30 rpm for 30-40 seconds, and then discharge the material to obtain the permeable concrete for the garden road.

[0014] The modified fiber reinforcement of the present invention is made of polypropylene imitation steel fibers and carbon nanotubes. The polypropylene imitation steel fibers form a three-dimensional network structure in concrete, inhibiting the expansion of microcracks through a physical "bridging" effect. The addition of carbon nanotubes (mass ratio of 10:1) further enhances the stiffness and tensile strength of the fibers, significantly improving the flexural strength and impact resistance of the concrete. After argon plasma activation and treatment with a KH-570 silane coupling agent, active groups (-Si-OH) are generated on the fiber surface, forming chemical bonds with cement hydration products (CSH gel) to reduce interfacial defects. The butylpyridine latex-resin coating layer (a three-dimensional network structure formed by cross-linking resorcinol / glutaraldehyde) enhances the bonding between the fiber and the matrix, preventing interfacial delamination caused by stress concentration. The pyridine ring in the butylpyridine latex has alkaline tolerance, can resist erosion by garden fertilizers and pesticides, and improve the durability of permeable concrete. The modified fiber reinforcement of the present invention is modified through three steps of "plasma activation-silane coupling-resin coating" to achieve efficient synergy between fiber and cement matrix and significantly improve the mechanical properties of concrete.

[0015] The nanocomposite air-entraining agent used in the present invention can produce evenly distributed nano-scale bubbles during the mixing process. These bubbles are stably wrapped by the gel network and are not easy to merge and break. The nano-bubbles are stabilized by "nano-SiO2-cellulose gel" to form an ice expansion pressure buffer system, thereby improving the freeze-thaw resistance of concrete. At the same time, the stable nano-bubbles adhere to the pore walls to form a hydrophobic layer, reducing the viscous resistance of water on the pore walls and accelerating the flow of water. Nano-SiO2 can also fill the nano-scale pores of cement stone, improve the density of the cement stone matrix, reduce the overflow of slurry into the large pores between aggregates, and avoid slurry blocking the main permeable channel. Nano-cellulose gel improves the toughness of the slurry and indirectly improves the compressive strength. The use of the nano-composite air-entraining agent of the present invention not only maintains the high permeability of permeable concrete but also significantly improves the freeze-thaw resistance and mechanical strength of concrete.

[0016] Compared with the existing technology, the beneficial effects of the present invention are as follows: the present invention forms a "continuous gradation + discontinuous gradation" composite skeleton by optimizing the aggregate gradation, and then adds an appropriate amount of silica fume and slag powder to fill part of the cement stone pores through the micro-aggregate effect, thereby further optimizing and adjusting the porosity; the rough surface of the modified fiber reinforcement provides an anchor point for the CSH gel, forming a "fiber-CSH-aggregate" three-dimensional network structure, and synergistically improving the mechanical properties; the nano-composite air-entraining agent introduces uniformly distributed and stable tiny bubbles through the synergistic effect of nano-silica and nano-cellulose, significantly improving the freeze-thaw resistance; the two optimize the structure from the macro scale (fiber network) and micro scale (bubbles / pores) respectively, and synergistically achieve a triple breakthrough in strength, durability and frost resistance while ensuring permeability, which is particularly suitable for garden road scenes with high requirements for ecology and durability. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be further described below with reference to specific embodiments, but the present invention is not limited thereto. In the following embodiments, cement is ordinary Portland cement, specifically ordinary Portland cement PO 42.5.

[0018] Example 1 A permeable concrete for a garden road is prepared from the following raw materials in parts by weight: 100 parts of cement, 300 parts of coarse aggregate, 80 parts of fine aggregate, 3 parts of a modified fiber reinforcing agent, 15 parts of silica fume, 20 parts of slag powder, 2 parts of a polycarboxylate water reducer, 0.1 part of a nano-composite air entraining agent, and 220 parts of water.

[0019] The modified fiber reinforcing agent is prepared by the following method: A, polypropylene imitation steel fibers and carbon nanotubes were mixed in a mass ratio of 10:1 and activated by argon plasma for 20 min at 10 kV and 50 kHz; B, the activated product was immersed in 5% KH-570 ethanol solution, reacted at 60℃ for 2-3h, and dried at 80℃ for 1h after the reaction to obtain a pretreated fiber mixture; C, deionized water, NaOH, and m-diphenol were mixed in proportion and magnetically stirred until transparent. Glutaraldehyde solution was slowly added dropwise at room temperature. After the addition, magnetic stirring was continued for 2 hours. Then, butylpyrrolidone latex was added and stirred at 600 rpm for 10 minutes until uniform. Then, 25% ammonia water was added dropwise and the pH was adjusted to 8.5 to obtain an emulsion; D. Immerse the pretreated fiber mixture obtained in step B into the emulsion obtained in step C, stir magnetically at 40° C. for 10 minutes, take it out, and dry it at 80° C. for 1 hour to obtain the modified fiber reinforcement.

[0020] In the step C, the mass ratio of deionized water, NaOH, m-diphenol, 50% glutaraldehyde solution, and butylpyrrolidone latex is 600:0.2:1:0.6:7; and the solid content of the butylpyrrolidone latex is 40%.

[0021] The preparation method of the nanocomposite air-entraining agent is as follows: (1) Nano-silica was dispersed in 10% ethanol and ultrasonically treated for 30-40 min. Then, silane coupling agent KH570 was added thereto, stirred and reacted at 70°C for 4 h, centrifuged and washed 3 times, and vacuum dried to obtain pretreated nano-silica; the mass ratio of nano-silica to KH570 was 3:1; (2) Add nanocellulose to deionized water and homogenize under high pressure to form a 1 wt% transparent gel solution; (3) The gel solution obtained in step (2) and the pretreated nano-silica obtained in step (1) were mixed in a mass ratio of 10:3, dispersed under 40 kHz ultrasonication for 1 hour, and then allowed to stand and age for 24 hours to obtain a composite gel material; (4) The composite gel material was diluted to a solid content of 0.5 wt%, and then the pH was adjusted to 9.0 with NaOH solution to obtain a nanocomposite air entraining agent.

[0022] The coarse aggregate is basalt crushed stone, wherein the mass ratio of the coarse aggregate with particle sizes of 15-20 mm and 10-15 mm is 2:5; the fine aggregate is river sand, wherein the mass ratio of the fine aggregate with particle sizes of 2-3 mm and 3.5-4.5 mm is 3:7.

[0023] The construction method of the above-mentioned garden road permeable concrete comprises the following steps: Step 1, mixing coarse aggregate and fine aggregate according to the required particle size ratio; Step 2: Prepare a modified fiber reinforcement, and put it into a mixer with coarse aggregate and fine aggregate for dry mixing; Step 3: Continue adding cement, silica fume, slag powder, and polycarboxylate water reducer into the mixer and continue stirring for 3-5 minutes to form a uniform mixture; Step 4: add 80% of the total water into the mixer, stir at 60 rpm for 1-2 minutes, then add the mixture consisting of the nano-composite air-entraining agent and the remaining 20% ​​of water, stir at 30 rpm for 30-40 seconds, and then discharge the material to obtain the permeable concrete for the garden road.

[0024] Example 2 A permeable concrete for a garden road is prepared from the following raw materials in parts by weight: 150 parts of cement, 360 parts of coarse aggregate, 100 parts of fine aggregate, 4 parts of a modified fiber reinforcement, 25 parts of silica fume, 30 parts of slag powder, 3 parts of a polycarboxylate water reducer, 0.2 parts of a nano-composite air entraining agent, and 240 parts of water.

[0025] The modified fiber reinforcing agent is prepared by the following method: A, polypropylene imitation steel fibers and carbon nanotubes were mixed in a mass ratio of 10:1 and activated by argon plasma for 20 min at 10 kV and 50 kHz; B, the activated product was immersed in 5% KH-570 ethanol solution, reacted at 60℃ for 2-3h, and dried at 80℃ for 1h after the reaction to obtain a pretreated fiber mixture; C, deionized water, NaOH, and m-diphenol were mixed in proportion and magnetically stirred until transparent. Glutaraldehyde solution was slowly added dropwise at room temperature. After the addition, magnetic stirring was continued for 2 hours. Then, butylpyrrolidone latex was added and stirred at 600 rpm for 10 minutes until uniform. Then, 25% ammonia water was added dropwise and the pH was adjusted to 8.5 to obtain an emulsion; D. Immerse the pretreated fiber mixture obtained in step B into the emulsion obtained in step C, stir magnetically at 40° C. for 10 minutes, take it out, and dry it at 80° C. for 1 hour to obtain the modified fiber reinforcement.

[0026] In the step C, the mass ratio of deionized water, NaOH, m-diphenol, 50% glutaraldehyde solution, and butylpyrrolidone latex is 600:0.2:1:0.6:7; and the solid content of the butylpyrrolidone latex is 40%.

[0027] The preparation method of the nanocomposite air-entraining agent is as follows: (1) Nano-silica was dispersed in 10% ethanol and ultrasonically treated for 30-40 min. Then, silane coupling agent KH570 was added thereto, stirred and reacted at 70°C for 4 h, centrifuged and washed 3 times, and vacuum dried to obtain pretreated nano-silica; the mass ratio of nano-silica to KH570 was 3:1; (2) Add nanocellulose to deionized water and homogenize under high pressure to form a 1 wt% transparent gel solution; (3) The gel solution obtained in step (2) and the pretreated nano-silica obtained in step (1) were mixed in a mass ratio of 10:3, dispersed under 40 kHz ultrasonication for 1 hour, and then allowed to stand and age for 24 hours to obtain a composite gel material; (4) The composite gel material was diluted to a solid content of 0.5 wt%, and then the pH was adjusted to 9.0 with NaOH solution to obtain a nanocomposite air entraining agent.

[0028] The coarse aggregate is basalt crushed stone, wherein the mass ratio of the coarse aggregate with particle sizes of 15-20 mm and 10-15 mm is 2:5; the fine aggregate is river sand, wherein the mass ratio of the fine aggregate with particle sizes of 2-3 mm and 3.5-4.5 mm is 3:7.

[0029] The construction method of the above-mentioned garden road permeable concrete comprises the following steps: Step 1, mixing coarse aggregate and fine aggregate according to the required particle size ratio; Step 2: Prepare a modified fiber reinforcement, and put it into a mixer with coarse aggregate and fine aggregate for dry mixing; Step 3: Continue adding cement, silica fume, slag powder, and polycarboxylate water reducer into the mixer and continue stirring for 3-5 minutes to form a uniform mixture; Step 4: add 80% of the total water into the mixer, stir at 60 rpm for 1-2 minutes, then add the mixture consisting of the nano-composite air-entraining agent and the remaining 20% ​​of water, stir at 30 rpm for 30-40 seconds, and then discharge the material to obtain the permeable concrete for the garden road.

[0030] Example 3 A permeable concrete for a garden road is prepared from the following raw materials in parts by weight: 120 parts of cement, 340 parts of coarse aggregate, 90 parts of fine aggregate, 3.5 parts of a modified fiber reinforcement, 20 parts of silica fume, 25 parts of slag powder, 2.5 parts of a polycarboxylate water reducer, 0.15 parts of a nano-composite air entraining agent, and 230 parts of water.

[0031] The modified fiber reinforcing agent is prepared by the following method: A, polypropylene imitation steel fibers and carbon nanotubes were mixed in a mass ratio of 10:1 and activated by argon plasma for 20 min at 10 kV and 50 kHz; B, the activated product was immersed in 5% KH-570 ethanol solution, reacted at 60℃ for 2-3h, and dried at 80℃ for 1h after the reaction to obtain a pretreated fiber mixture; C, deionized water, NaOH, and m-diphenol were mixed in proportion and magnetically stirred until transparent. Glutaraldehyde solution was slowly added dropwise at room temperature. After the addition, magnetic stirring was continued for 2 hours. Then, butylpyrrolidone latex was added and stirred at 600 rpm for 10 minutes until uniform. Then, 25% ammonia water was added dropwise and the pH was adjusted to 8.5 to obtain an emulsion; D. Immerse the pretreated fiber mixture obtained in step B into the emulsion obtained in step C, stir magnetically at 40° C. for 10 minutes, take it out, and dry it at 80° C. for 1 hour to obtain the modified fiber reinforcement.

[0032] In the step C, the mass ratio of deionized water, NaOH, m-diphenol, 50% glutaraldehyde solution, and butylpyrrolidone latex is 600:0.2:1:0.6:7; and the solid content of the butylpyrrolidone latex is 40%.

[0033] The preparation method of the nanocomposite air-entraining agent is as follows: (1) Nano-silica was dispersed in 10% ethanol and ultrasonically treated for 30-40 min. Then, silane coupling agent KH570 was added thereto, stirred and reacted at 70°C for 4 h, centrifuged and washed 3 times, and vacuum dried to obtain pretreated nano-silica; the mass ratio of nano-silica to KH570 was 3:1; (2) Add nanocellulose to deionized water and homogenize under high pressure to form a 1 wt% transparent gel solution; (3) The gel solution obtained in step (2) and the pretreated nano-silica obtained in step (1) were mixed in a mass ratio of 10:3, dispersed under 40 kHz ultrasonication for 1 hour, and then allowed to stand and age for 24 hours to obtain a composite gel material; (4) The composite gel material was diluted to a solid content of 0.5 wt%, and then the pH was adjusted to 9.0 with NaOH solution to obtain a nanocomposite air entraining agent.

[0034] The coarse aggregate is basalt crushed stone, wherein the mass ratio of the coarse aggregate with particle sizes of 15-20 mm and 10-15 mm is 2:5; the fine aggregate is river sand, wherein the mass ratio of the fine aggregate with particle sizes of 2-3 mm and 3.5-4.5 mm is 3:7.

[0035] The construction method of the above-mentioned garden road permeable concrete comprises the following steps: Step 1, mixing coarse aggregate and fine aggregate according to the required particle size ratio; Step 2: Prepare a modified fiber reinforcement, and put it into a mixer with coarse aggregate and fine aggregate for dry mixing; Step 3: Continue adding cement, silica fume, slag powder, and polycarboxylate water reducer into the mixer and continue stirring for 3-5 minutes to form a uniform mixture; Step 4: add 80% of the total water into the mixer, stir at 60 rpm for 1-2 minutes, then add the mixture consisting of the nano-composite air-entraining agent and the remaining 20% ​​of water, stir at 30 rpm for 30-40 seconds, and then discharge the material to obtain the permeable concrete for the garden road.

[0036] Comparative Example 1 A permeable concrete for garden roads, whose raw material composition and preparation method are basically the same as those in Example 1, the only difference being that the modified fiber reinforcement is replaced by polypropylene imitation steel fiber.

[0037] Comparative Example 2 A permeable concrete for garden roads, whose raw material composition and preparation method are basically the same as those in Example 1, the only difference being that the nanocomposite air-entraining agent is replaced by a conventional rosin resin air-entraining agent.

[0038] Comparative Example 3 A permeable concrete for garden roads, whose raw material composition and preparation method are basically the same as those in Example 1, except that the modified fiber reinforcement is replaced by ordinary polypropylene imitation steel fiber, and the nano-composite air entraining agent is replaced by a conventional rosin resin air entraining agent.

[0039] Comparative Example 4 A conventional permeable concrete is made from the following ingredients: 150 parts cement, 350 parts coarse aggregate (single-graded 10-15mm basalt crushed stone), 2 parts polycarboxylate superplasticizer, and 180 parts water. During construction, simply mix all ingredients and stir.

[0040] Performance Testing Test methods and standards Permeability coefficient: According to the test method for permeable cement concrete pavement materials in GB / T 25993-2010, the permeability rate (mm / s) under a water head of 30 cm is measured.

[0041] Mechanical Properties: Compressive strength was measured using 100 mm cubic specimens prepared according to GB / T 50081-2019 and tested after 28 days of curing. Flexural strength was measured using prismatic specimens (100 mm × 100 mm × 400 mm) prepared according to the same standard. Freeze-thaw resistance was measured using the rapid freezing method (-20°C to 20°C cycling) according to GB / T 50082-2009, with the compressive strength loss rate measured after 50 cycles.

[0042] Chemical resistance: Test specimens were immersed in a 5% urea + 2% ammonium sulfate solution (simulating garden fertilizer) for 28 days. The mass loss and compressive strength loss rates were measured. The test results are shown in Table 1 below.

[0043] Table 1 Performance test results As can be seen from the results in Table 1 above, the permeable coefficient of the permeable concrete obtained in the embodiment of the present invention (3.8-4.1 mm / s) meets the requirements of garden roads (>2 mm / s), and the 28-day compressive strength and 28-day flexural strength are significantly higher than those of the comparative example. The compressive strength loss rate after 50 cycles in the freeze-thaw test, the 28-day mass loss rate and compressive strength loss rate in the corrosion resistance test are significantly lower than those of the comparative example. This shows that the permeable concrete prepared by the present invention maintains excellent mechanical properties while maintaining good permeability, and has excellent freeze-thaw resistance and chemical corrosion resistance in low temperature environments. It is particularly suitable for garden road scenarios with high ecological requirements (permeability), high loads (garden vehicles) and severe cold / corrosive environments (fertilizers, snow melting agents), and has broad market application prospects. The present invention achieves this through the synergistic effects of "aggregate gradation optimization (intermittently graded basalt / river sand) + modified fiber reinforcement + nano-composite air-entraining agent." The coarse aggregate and fine aggregate form a stable skeleton, ensuring permeable channels. The modified fiber reinforcement chemically bonds with the CSH gel to inhibit crack propagation and achieve high flexural strength. Simultaneously, the hydroquinone / glutaraldehyde cross-linking network strengthens the fiber-matrix interface bonding, improving overall mechanical properties. The nano-composite air-entraining agent introduces evenly distributed and stable micro-bubbles, significantly improving freeze-thaw resistance. The various raw materials of the present invention work together to optimize the structure at both the macroscale (fiber network) and the microscale (bubbles / pores). While ensuring water permeability, the synergistic effects achieve a triple breakthrough in strength, durability, and frost resistance.

[0044] It should be noted that the above embodiments are only some of the preferred embodiments of the present invention, and not all of them. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

Claims

1. A permeable concrete for garden roads, characterized in that: The invention is prepared from the following raw materials in parts by weight: 100-150 parts of cement, 300-360 parts of coarse aggregate, 80-100 parts of fine aggregate, 3-4 parts of modified fiber reinforcing agent, 15-25 parts of silica fume, 20-30 parts of slag powder, 2-3 parts of polycarboxylic acid water reducer, 0.1-0.2 parts of nano composite air entraining agent and 220-240 parts of water.

2. The permeable concrete for garden roads according to claim 1, characterized in that: The modified fiber reinforcing agent is prepared by the following method: A, polypropylene imitation steel fiber and carbon nanotubes were mixed according to the mass ratio and activated by argon plasma for 20 minutes; B, the activated product was immersed in 5% KH-570 ethanol solution, reacted at 60℃ for 2-3h, and dried at 80℃ for 1h after the reaction to obtain a pretreated fiber mixture; C, deionized water, NaOH, and m-diphenol were mixed in proportion and magnetically stirred until transparent. Glutaraldehyde solution was slowly added dropwise at room temperature. After the addition, magnetic stirring was continued for 2 hours. Then, butylpyrrolidone latex was added and stirred at 600 rpm for 10 minutes until uniform. Then, 25% ammonia water was added dropwise and the pH was adjusted to 8.5 to obtain an emulsion; D. Immerse the pretreated fiber mixture obtained in step B into the emulsion obtained in step C, stir magnetically at 40° C. for 10 minutes, take it out, and dry it at 80° C. for 1 hour to obtain the modified fiber reinforcement.

3. The permeable concrete for garden roads according to claim 2, characterized in that: In step A, the mass ratio of polypropylene imitation steel fiber to carbon nanotube is 10:1; and the argon plasma activation conditions are 10 kV and 50 kHz.

4. The permeable concrete for garden roads according to claim 2, characterized in that: In the step C, the mass ratio of deionized water, NaOH, m-diphenol, 50% glutaraldehyde solution, and butylpyrrolidone latex is 600:0.2:1:0.6:7; and the solid content of the butylpyrrolidone latex is 40%.

5. The permeable concrete for garden roads according to claim 1, characterized in that: The preparation method of the nanocomposite air-entraining agent is as follows: (1) Dispersing nano-silica in 10% ethanol, ultrasonically treating for 30-40 min, then adding silane coupling agent, stirring at 70 ° C for 4 h, centrifuging and washing 3 times, and vacuum drying to obtain pretreated nano-silica; (2) Add nanocellulose to deionized water and homogenize under high pressure to form a 1 wt% transparent gel solution; (3) The gel solution obtained in step (2) and the pretreated nano-silica obtained in step (1) were mixed according to a mass ratio, dispersed by ultrasonic at 40 kHz for 1 hour, and then allowed to stand and age for 24 hours to obtain a composite gel material; (4) The composite gel material was diluted to a solid content of 0.5 wt%, and then the pH was adjusted to 9.0 with NaOH solution to obtain a nanocomposite air entraining agent.

6. The permeable concrete for garden roads according to claim 5, characterized in that: In the step (1), the silane coupling agent is KH570, and the mass ratio of nano-silica to KH570 is 3:

1.

7. The permeable concrete for garden roads according to claim 5, characterized in that: In step (3), the mass ratio of the gel solution to the pretreated nano-silica is 10:

3.

8. The permeable concrete for garden roads according to claim 1, characterized in that: The coarse aggregate is basalt crushed stone, wherein the mass ratio of the coarse aggregate with particle sizes of 15-20 mm and 10-15 mm is 2:5; the fine aggregate is river sand, wherein the mass ratio of the fine aggregate with particle sizes of 2-3 mm and 3.5-4.5 mm is 3:

7.

9. A construction method for permeable concrete for garden roads according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1, mixing coarse aggregate and fine aggregate according to the required particle size ratio; Step 2: Prepare a modified fiber reinforcement, and put it into a mixer with coarse aggregate and fine aggregate for dry mixing; Step 3: Continue adding cement, silica fume, slag powder, and polycarboxylate water reducer into the mixer and continue stirring for 3-5 minutes to form a uniform mixture; Step 4: add 80% of the total water into the mixer, stir at 60 rpm for 1-2 minutes, then add the mixture consisting of the nano-composite air-entraining agent and the remaining 20% ​​of water, stir at 30 rpm for 30-40 seconds, and then discharge the material to obtain the permeable concrete for the garden road.

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