High-strength pervious concrete and preparation method thereof

Abstract

The invention discloses high-strength pervious concrete and a preparation method thereof, and relates to the technical field of concrete materials. The steel slag is used as a raw material, elements such as iron, magnesium, manganese, calcium, silicon, aluminum, chromium and the like are obtained through low-temperature carbon thermal reduction and precise impurity removal, then special-shaped fibers are obtained through bonding plasticity of silica sol to metal materials, and therefore the water permeability and high mechanical performance of the concrete are achieved. Then the metal fibers and the shear particles thereof are subjected to laser treatment under different auxiliary conditions; wherein a bionic ant-cave-shaped structure is constructed on the fiber surface by utilizing ultrasonic-assisted laser, so that the drainage effect of the concrete is further improved, meanwhile, metal is promoted to generate a ceramic phase surface through an oxidation condition, the concrete is further strengthened, and a granular material is subjected to ammonia-assisted laser treatment, and through hydroxyl groups on the surface and a crystal nucleus effect of the hydroxyl groups, the water drainage effect of the concrete is improved. The mechanical property of the concrete is improved again.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete materials, in particular to high-strength permeable concrete and a preparation method thereof. Background Art

[0002] In recent years, with the rapid urbanization of my country, much of the urban surface has been covered by various buildings and impermeable pavements. However, these impermeable pavements have had some adverse impacts on the urban ecological environment. For example, prolonged heavy rainfall can cause water to accumulate on impermeable pavements, increasing the load on urban drainage systems and causing urban flooding. Furthermore, impermeable pavements have a low heat capacity and cannot fully exchange heat with the air, resulting in high surface temperatures and a heat island effect. To address this urgent problem and reduce unnecessary losses, the concept of "sponge cities" has emerged. Also known as "water-resilient cities," sponge cities are designed to absorb, store, infiltrate, and purify water during rainfall, and release stored water for reuse during droughts, giving cities a degree of resilience to natural disasters. Furthermore, problems such as urban flooding and acid rain erosion have become prominent in my country's southeastern coastal areas. Acid rain can further cause sulfate erosion and damage urban roads.

[0003] Permeable concrete is a key component of sponge city construction. Composed primarily of coarse aggregate, cement, water, admixtures, and additives, it is a green building material with numerous interconnected pores. These interconnected pores not only relieve pressure on urban drainage systems but also allow rainwater to quickly infiltrate the ground, replenishing groundwater resources. However, cement permeable concrete suffers from poor mechanical properties, making it more susceptible to acid rain and sulfate attack. Therefore, the development of high-strength permeable concrete is crucial. Summary of the Invention

[0004] The object of the present invention is to provide a high-strength permeable concrete and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing high-strength permeable concrete, comprising the following steps:

[0006] (1) Grind the steel slag until it passes through a 200-mesh sieve, pour it into an 8 wt% sulfuric acid solution, stir it at 200 rpm for 10-15 h, filter it, and wash it with deionized water until the pH of the filtrate is 7. After drying at 120°C for 6 h, mix it with carbon powder and perform a reduction treatment to obtain a refined powder;

[0007] (2) Silica sol, refined powder, metal additive, polyvinyl pyrrolidone, and N,N-dimethylformamide are uniformly mixed and spun using a cross-shaped spinneret. The resulting fiber is then heated at 300-400°C under nitrogen protection for 5-8 hours, then heated to 800-1000°C and calcined for 0.5-2 hours to obtain a fiber material;

[0008] (3) laser treating the fiber material in an oxygen atmosphere and performing annealing to enhance the stability of the material to obtain filler A;

[0009] (4) Shearing the fiber material into a material with a particle size of 0.1 to 0.5 mm, laser processing it in a liquid environment, and annealing it to obtain filler B;

[0010] (5) 1 / 5 of the mass of deionized water was first mixed with melon stone, recycled aggregate with a particle size of 4.7 mm, and recycled aggregate with a particle size of 9.5 mm, and stirred at 60 rpm for 100 s. Filler A, filler B, polypropylene fiber, water-based epoxy resin, and 1 / 2 of the mass of deionized water were added and stirred for 100 to 200 s. The water reducer and the remaining deionized water were added, and finally stirred for 100 s to obtain high-strength permeable concrete.

[0011] Furthermore, the chemical components of the steel slag in step (1) are as follows: 37.42% by weight of iron oxide, 31.98% by weight of calcium oxide, 12.63% by weight of silicon dioxide, 5.35% by weight of aluminum oxide, 5.32% by weight of magnesium oxide, 4.07% by weight of manganese oxide, 1.72% by weight of chromium oxide, and 1.17% by weight of others.

[0012] Furthermore, the specific steps of the reduction treatment in step (1) are: first, the slag is treated for 30 to 90 minutes under the conditions of a vacuum degree of 10 Pa and a temperature of 600 to 750°C, and then the iron is recovered. The remaining slag is further heated to 1200 to 1500°C and treated for 30 to 90 minutes to obtain a partial reduction product. Finally, hydrogen is introduced and the temperature is raised to 1500 to 2000°C and treated for 30 minutes to obtain the remaining reduction product.

[0013] Furthermore, the mass ratio of the steel slag, 8wt% sulfuric acid solution and carbon powder in step (1) is 10:80:1-3.

[0014] Furthermore, the spinning rate in step (2) is 1000-1500 m / min.

[0015] Furthermore, the mass ratio of the silica sol, refined powder, metal additive, polyvinyl pyrrolidone and N,N-dimethylformamide in step (2) is 1:0.5:0.05-0.1:0.2-0.4:0.1.

[0016] Furthermore, the metal auxiliary agent in step (2) is at least one of zirconium sulfate, aluminum chloride, titanium orthosulfate, magnesium sulfide, and tin chloride.

[0017] Furthermore, the process conditions of the laser treatment in step (3) are: power of 600mW, pulse width of 40fs, wavelength of 800-1100nm, pulse frequency of 1kHz, scanning speed of 1mm / s, spacing of 60-120μm, and ultrasonic power of 100W.

[0018] Furthermore, the process conditions of the laser treatment in step (4) are: the auxiliary liquid is 5-30wt% ammonia solution, the power is 600mW, the scanning speed is 350mm / s, the number of scans is 5-10 times, the wavelength is 800-1100nm, the pulse width is 40fs, and the pulse frequency is 5-25kHz.

[0019] Furthermore, in step (5), the mass ratio of the melon stone, the recycled aggregate with a particle size of 4.7 mm, the recycled aggregate with a particle size of 9.5 mm, filler A, filler B, polypropylene fiber, water-based epoxy resin, water reducer, and deionized water is 250:70:70:0.5~2:0.1~0.5:0.1:3:1:40~50.

[0020] Compared with the existing technology, the beneficial effects achieved are:

[0021] The steel slag of the present invention is used as raw material, and elemental iron is obtained by low-temperature carbon thermal reduction. The remaining slag is then precisely removed to obtain elemental substances such as magnesium, manganese, calcium, silicon, aluminum, and chromium. Silica sol is then used to bond and plasticize the metal material to obtain special-shaped fibers, which are connected through contact points in the concrete to form a three-dimensional network drainage channel. The fibers are like "micro-rebars", which not only play the role of "bridging fibers" but also cross with the fiber materials around the matrix to form a network structure. The interaction between the two limits the relative displacement of aggregates in the concrete, and can also ensure the strength of the surface transition zone and the fiber anchoring effect in the concrete, thereby achieving permeability and high mechanical properties. Finally, the metal fibers and their sheared particles are laser treated with different auxiliary conditions.

[0022] Among them, ultrasound-assisted laser is used to construct a bionic ant-hole structure dominated by the subcrystalline phase on the fiber surface. This unique multi-level micro-nano structure helps to achieve stable utilization of air capture and greatly reduce the surface free energy of the material, thereby achieving an efficient and stable self-starting superhydrophobic effect, further enhancing the drainage effect of concrete. At the same time, through oxidation conditions, the metal is prompted to generate a ceramic phase surface, thereby enhancing the chemical stability of the material, thereby further strengthening the concrete. The granular material is treated with ammonia-assisted laser, which can not only enhance the chemical stability of the material, but also facilitate the formation of a stable spatial structure of the hydration product through the hydroxyl groups generated on the surface and its "nucleus effect", thereby enhancing the bonding strength between the geopolymer and the aggregate. In addition, a small amount of chromium in the metal can form chemical bonds with polymer substances, further enhancing the mechanical properties of the matrix. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the high-strength permeable concrete prepared in the following examples.

[0025] Mechanical properties: The concrete of the embodiment and the comparative example were made into specimens with a size of 100 mm×100 mm×100 mm, and the compressive strength of the specimens at 28 days was tested with reference to GB / T50081.

[0026] Water permeability: The concrete of the embodiment and the comparative example was made into specimens with a diameter of 100 mm and a height of 50 mm. The water permeability coefficient was tested using a STA type water permeability meter according to CJJ / T135.

[0027] Example 1

[0028] (1) The steel slag was ground to pass through a 200-mesh sieve, poured into an 8 wt% sulfuric acid solution, stirred at 200 rpm for 10 h, filtered and washed with deionized water until the pH of the filtrate was 7, dried at 120 ° C for 6 h, mixed with carbon powder, and subjected to reduction treatment: first, the slag was treated at a vacuum degree of 10 Pa and a temperature of 600 ° C for 30 min, and then the iron was recovered. The remaining slag was further heated to 1200 ° C and treated for 30 min to obtain a partially reduced product. Finally, hydrogen was introduced at a flow rate of 0.7 L / min and a time of 3 0min, and heating to 1500℃, treating for 30min to obtain residual reduction product, and finally mixing the three to obtain refined powder; the mass ratio of the steel slag, 8wt% sulfuric acid solution, and carbon powder is 10:80:1; the mass percentage of the chemical composition of the steel slag is 37.42% iron oxide, 31.98% calcium oxide, 12.63% silicon dioxide, 5.35% aluminum oxide, 5.32% magnesium oxide, 4.07% manganese oxide, 1.72% chromium oxide, and 1.17% others; the particle size of the carbon powder is 10μm;

[0029] (2) Silica sol, refined powder, zirconium sulfate, polyvinyl pyrrolidone, and N,N-dimethylformamide were uniformly mixed and spun using a cross-shaped spinneret at a spinning speed of 1000 m / min. The obtained fiber was then kept at 300°C under nitrogen protection for 5 hours, then heated to 800°C and calcined for 0.5 hours to obtain a fiber material; the mass ratio of the silica sol, refined powder, zirconium sulfate, polyvinyl pyrrolidone, and N,N-dimethylformamide was 1:0.5:0.05:0.2:0.1; the silica sol was KHAS silica sol from Shandong Kehan Silicon Source; the molecular weight of the polyvinyl pyrrolidone was 1300000; the length of the fiber material was 15 mm;

[0030] (3) The fiber material was laser treated in an oxygen atmosphere under the following process conditions: power of 600 mW, pulse width of 40 fs, wavelength of 800 nm, pulse frequency of 1 kHz, scanning speed of 1 mm / s, spacing of 60 μm, and ultrasonic power of 100 W. The material was then annealed at 400°C for 1 h to enhance its stability, thereby obtaining filler A.

[0031] (4) The fiber material was sheared into a material with a particle size of 0.1 mm and subjected to laser treatment in a liquid environment. The process conditions were: auxiliary liquid was 5 wt% ammonia solution, power was 600 mW, scanning speed was 350 mm / s, number of scans was 5 times, wavelength was 800 nm, pulse width was 40 fs, pulse frequency was 5 kHz, and finally annealing treatment was performed at a temperature of 400 ° C and time was 1 h to obtain filler B;

[0032] (5) 1 / 5 of the mass of deionized water was first mixed with melon stone, recycled aggregate with a particle size of 4.7 mm, and recycled aggregate with a particle size of 9.5 mm, and stirred at 60 rpm for 100 s, and filler A, filler B, polypropylene fiber, water-based epoxy resin, and 1 / 2 of the mass of deionized water were added, and stirred for 100 s, and a water reducer and the remaining deionized water were added, and finally stirred for 100 s to obtain high-strength permeable concrete; the mass ratio of the melon stone, recycled aggregate with a particle size of 4.7 mm, recycled aggregate with a particle size of 9.5 mm, filler A, filler B, polypropylene fiber, water-based epoxy resin, water reducer, and deionized water was 250:70:70:0.5:0.1:0.1:3:1:40; the particle size of the melon stone was 5 mm; the density of the polypropylene fiber was 0.9 g cm -3 , length 12mm, diameter 0.03mm; the water-based epoxy resin is H123AB water-based epoxy resin; the water reducer is PC-1007 polycarboxylic acid high-performance water reducer.

[0033] Example 2

[0034] (1) The steel slag was ground to pass through a 200-mesh sieve, poured into an 8 wt% sulfuric acid solution, stirred at 200 rpm for 12 h, filtered, and washed with deionized water until the pH of the filtrate was 7. After drying at 120 °C for 6 h, it was mixed with carbon powder and subjected to reduction treatment: first, the slag was treated at a vacuum degree of 10 Pa and a temperature of 700 °C for 60 min, and then the iron was recovered. The remaining slag was further heated to 1350 °C and treated for 60 min to obtain a partially reduced product. Finally, hydrogen was introduced at a flow rate of 0.7 L / min for 3 min. 0min, and heating to 1800℃, treating for 30min to obtain residual reduction product, and finally mixing the three to obtain refined powder; the mass ratio of the steel slag, 8wt% sulfuric acid solution, and carbon powder is 10:80:2; the mass percentage of the chemical composition of the steel slag is 37.42% iron oxide, 31.98% calcium oxide, 12.63% silicon dioxide, 5.35% aluminum oxide, 5.32% magnesium oxide, 4.07% manganese oxide, 1.72% chromium oxide, and 1.17% others; the particle size of the carbon powder is 10μm;

[0035] (2) Silica sol, refined powder, zirconium sulfate, polyvinyl pyrrolidone, and N,N-dimethylformamide were uniformly mixed and spun using a cross-shaped spinneret at a spinning speed of 1300 m / min. The obtained fiber was then kept at 350°C under nitrogen protection for 6.5 hours, then heated to 900°C and calcined for 1 hour to obtain a fiber material; the mass ratio of the silica sol, refined powder, zirconium sulfate, polyvinyl pyrrolidone, and N,N-dimethylformamide was 1:0.5:0.08:0.3:0.1; the silica sol was KHAS silica sol from Shandong Kehan Silicon Source; the molecular weight of the polyvinyl pyrrolidone was 1300000; the length of the fiber material was 15 mm;

[0036] (3) The fiber material was laser treated in an oxygen atmosphere under the following process conditions: power of 600 mW, pulse width of 40 fs, wavelength of 1000 nm, pulse frequency of 1 kHz, scanning speed of 1 mm / s, spacing of 90 μm, and ultrasonic power of 100 W. The material was then annealed at 400°C for 1 h to enhance its stability, thereby obtaining filler A.

[0037] (4) The fiber material was sheared into a material with a particle size of 0.3 mm and subjected to laser treatment in a liquid environment. The process conditions were: auxiliary liquid was 18 wt% ammonia solution, power was 600 mW, scanning speed was 350 mm / s, number of scans was 7 times, wavelength was 1000 nm, pulse width was 40 fs, pulse frequency was 16 kHz, and finally annealing treatment was performed at a temperature of 400 ° C and time was 1 h to obtain filler B;

[0038] (5) 1 / 5 of the mass of deionized water was first mixed with melon stone, recycled aggregate with a particle size of 4.7 mm, and recycled aggregate with a particle size of 9.5 mm, and stirred at 60 rpm for 100 s, and filler A, filler B, polypropylene fiber, water-based epoxy resin, and 1 / 2 of the mass of deionized water were added, and stirred for 150 s, and a water reducer and the remaining deionized water were added, and finally stirred for 100 s to obtain high-strength permeable concrete; the mass ratio of the melon stone, recycled aggregate with a particle size of 4.7 mm, recycled aggregate with a particle size of 9.5 mm, filler A, filler B, polypropylene fiber, water-based epoxy resin, water reducer, and deionized water was 250:70:70:1.3:0.3:0.1:3:1:45; the particle size of the melon stone was 8 mm; the density of the polypropylene fiber was 0.9 g·cm -3 , length 12mm, diameter 0.03mm; the water-based epoxy resin is H123AB water-based epoxy resin; the water reducer is PC-1007 polycarboxylic acid high-performance water reducer.

[0039] Example 3

[0040] (1) The steel slag was ground to pass through a 200-mesh sieve, poured into an 8 wt% sulfuric acid solution, stirred at 200 rpm for 15 h, filtered, and washed with deionized water until the pH of the filtrate was 7. After drying at 120 °C for 6 h, it was mixed with carbon powder and subjected to reduction treatment: first, the slag was treated at a vacuum degree of 10 Pa and a temperature of 750 °C for 90 min, and then the iron was recovered. The remaining slag was further heated to 1500 °C and treated for 90 min to obtain a partially reduced product. Finally, hydrogen was introduced at a flow rate of 0.7 L / min for 3 min. 0min, and heating to 2000℃, treating for 30min to obtain residual reduction product, and finally mixing the three to obtain refined powder; the mass ratio of the steel slag, 8wt% sulfuric acid solution, and carbon powder is 10:80:3; the mass percentage of the chemical composition of the steel slag is 37.42% iron oxide, 31.98% calcium oxide, 12.63% silicon dioxide, 5.35% aluminum oxide, 5.32% magnesium oxide, 4.07% manganese oxide, 1.72% chromium oxide, and 1.17% others; the particle size of the carbon powder is 10μm;

[0041] (2) Silica sol, refined powder, zirconium sulfate, polyvinyl pyrrolidone, and N,N-dimethylformamide were uniformly mixed and spun using a cross-shaped spinneret at a spinning speed of 1500 m / min. The obtained fiber was then kept at 400°C under nitrogen protection for 8 hours, then heated to 1000°C and calcined for 2 hours to obtain a fiber material; the mass ratio of the silica sol, refined powder, zirconium sulfate, polyvinyl pyrrolidone, and N,N-dimethylformamide was 1:0.5:0.1:0.4:0.1; the silica sol was KHAS silica sol from Shandong Kehan Silicon Source; the molecular weight of the polyvinyl pyrrolidone was 1300000; and the length of the fiber material was 15 mm;

[0042] (3) The fiber material was laser treated in an oxygen atmosphere under the following process conditions: power of 600 mW, pulse width of 40 fs, wavelength of 1100 nm, pulse frequency of 1 kHz, scanning speed of 1 mm / s, spacing of 120 μm, and ultrasonic power of 100 W. The material was then annealed at 400°C for 1 h to enhance its stability, thereby obtaining filler A.

[0043] (4) The fiber material was sheared into a material with a particle size of 0.5 mm and subjected to laser treatment in a liquid environment. The process conditions were: auxiliary liquid was 30 wt% ammonia solution, power was 600 mW, scanning speed was 350 mm / s, number of scans was 10 times, wavelength was 1100 nm, pulse width was 40 fs, pulse frequency was 25 kHz, and finally annealing treatment was performed at a temperature of 400 ° C and time was 1 h to obtain filler B;

[0044] (5) 1 / 5 of the mass of deionized water was first mixed with melon stone, recycled aggregate with a particle size of 4.7 mm, and recycled aggregate with a particle size of 9.5 mm, and stirred at 60 rpm for 100 s, and filler A, filler B, polypropylene fiber, water-based epoxy resin, and 1 / 2 of the mass of deionized water were added, and stirred for 200 s, and a water reducer and the remaining deionized water were added, and finally stirred for 100 s to obtain high-strength permeable concrete; the mass ratio of the melon stone, recycled aggregate with a particle size of 4.7 mm, recycled aggregate with a particle size of 9.5 mm, filler A, filler B, polypropylene fiber, water-based epoxy resin, water reducer, and deionized water was 250:70:70:2:0.5:0.1:3:1:50; the particle size of the melon stone was 10 mm; the density of the polypropylene fiber was 0.9 g cm -3 , length 12mm, diameter 0.03mm; the water-based epoxy resin is H123AB water-based epoxy resin; the water reducer is PC-1007 polycarboxylic acid high-performance water reducer.

[0045] Comparative Example 1

[0046] The difference between Comparative Example 1 and Example 2 is that step (2) is different. Step (2) is changed to: the silica sol, refined powder, zirconium sulfate, polyvinyl pyrrolidone, and N,N-dimethylformamide are mixed evenly and spun at a rate of 1300 m / min, and then the obtained fiber is kept at 350°C under nitrogen protection for 6.5 hours, then heated to 900°C and calcined for 1 hour to obtain a fiber material; the mass ratio of the silica sol, refined powder, zirconium sulfate, polyvinyl pyrrolidone, and N,N-dimethylformamide is 1:0.5:0.08:0.3:0.1; the silica sol is KHAS silica sol from Shandong Kehan Silicon Source; the molecular weight of the polyvinyl pyrrolidone is 1300000; the length of the cross-shaped fiber material is 15 mm; the remaining steps are the same as Example 2.

[0047] Comparative Example 2

[0048] Comparative Example 2 differs from Example 2 in that there is no step (3), and step (5) is changed to: 1 / 5 of the mass of deionized water is first mixed with melon stone, a recycled aggregate with a particle size of 4.7 mm, and a recycled aggregate with a particle size of 9.5 mm, stirred at 60 rpm for 100 s, fibrous material, filler B, polypropylene fiber, water-based epoxy resin and 1 / 2 of the mass of deionized water are added, stirred for 150 s, a water reducer and the remaining deionized water are added, and finally stirred for 100 s to obtain high-strength permeable concrete; the mass ratio of the melon stone, the recycled aggregate with a particle size of 4.7 mm, the recycled aggregate with a particle size of 9.5 mm, the fibrous material, filler B, polypropylene fiber, water-based epoxy resin, water reducer and deionized water is 250:70:70:1.3:0.3:0.1:3:1:45; the particle size of the melon stone is 8 mm; the density of the polypropylene fiber is 0.9 g cm -3 , length 12 mm, diameter 0.03 mm; the water-based epoxy resin is H123AB water-based epoxy resin; the water-reducing agent is PC-1007 polycarboxylic acid high-performance water-reducing agent; the remaining steps are the same as in Example 2.

[0049] Comparative Example 3

[0050] The difference between Comparative Example 3 and Example 2 is that step (4) is different. Step (4) is changed to: shearing the cross-shaped fiber material into a material with a particle size of 0.3 mm to obtain filler B; the remaining steps are the same as Example 2.

[0051] Comparative Example 4

[0052] Comparative Example 4 differs from Example 2 in that there is no step (3), and step (5) is changed to: 1 / 5 of the mass of deionized water is first mixed with melon stone, a recycled aggregate with a particle size of 4.7 mm, and a recycled aggregate with a particle size of 9.5 mm, stirred at 60 rpm for 100 s, filler B, polypropylene fiber, water-based epoxy resin and 1 / 2 of the mass of deionized water are added, stirred for 150 s, a water reducer and the remaining deionized water are added, and finally stirred for 100 s to obtain high-strength permeable concrete; the mass ratio of the melon stone, the recycled aggregate with a particle size of 4.7 mm, the recycled aggregate with a particle size of 9.5 mm, filler B, polypropylene fiber, water-based epoxy resin, water reducer and deionized water is 250:70:70:0.3:0.1:3:1:45; the particle size of the melon stone is 8 mm; the density of the polypropylene fiber is 0.9 g cm -3 , length 12 mm, diameter 0.03 mm; the water-based epoxy resin is H123AB water-based epoxy resin; the water-reducing agent is PC-1007 polycarboxylic acid high-performance water-reducing agent; the remaining steps are the same as in Example 2.

[0053] Comparative Example 5

[0054] Comparative Example 5 differs from Example 2 in that there is no step (4), and step (5) is changed to: 1 / 5 of the mass of deionized water is first mixed with melon stone, a recycled aggregate with a particle size of 4.7 mm, and a recycled aggregate with a particle size of 9.5 mm, stirred at 60 rpm for 100 s, filler A, polypropylene fiber, water-based epoxy resin and 1 / 2 of the mass of deionized water are added, stirred for 150 s, a water reducer and the remaining deionized water are added, and finally stirred for 100 s to obtain high-strength permeable concrete; the mass ratio of the melon stone, the recycled aggregate with a particle size of 4.7 mm, the recycled aggregate with a particle size of 9.5 mm, filler A, polypropylene fiber, water-based epoxy resin, water reducer and deionized water is 250:70:70:1.3:0.1:3:1:45; the particle size of the melon stone is 8 mm; the density of the polypropylene fiber is 0.9 g cm -3 , length 12 mm, diameter 0.03 mm; the water-based epoxy resin is H123AB water-based epoxy resin; the water-reducing agent is PC-1007 polycarboxylic acid high-performance water-reducing agent; the remaining steps are the same as in Example 2.

[0055] Effect Examples

[0056] Table 1 below shows the performance analysis results of the high-strength permeable concrete using Examples 1 to 3 of the present invention and Comparative Examples 1 to 5.

[0057] Table 1

[0058] Compressive strength (MPa) Water permeability (cm / s) Example 1 42 0.43 Example 2 46 0.47 Example 3 43 0.44 Comparative Example 1 42 0.31 Comparative Example 2 40 0.33 Comparative Example 3 38 0.42 Comparative Example 4 32 0.24 Comparative Example 5 35 0.39

[0059] From the comparison of the experimental data of the embodiment and the comparative example in Table 1, it can be found that the steel slag of the present invention is used as a raw material, and elemental iron is obtained by low-temperature carbon thermal reduction, and then elemental substances such as magnesium, manganese, calcium, silicon, aluminum, and chromium are obtained. Then, silica sol is used to bond the metal material to plasticity, thereby obtaining special-shaped fibers, thereby forming a three-dimensional network drainage channel in the concrete through contact points. The fibers are like "micro-rebars", not only playing the role of "bridging fibers", but also intersecting with the fiber materials around the matrix to form a network structure, thereby achieving water permeability and high mechanical properties. Finally, the metal fibers and their sheared particles are laser-treated under different auxiliary conditions; among them, ultrasound-assisted laser is used to form a multi-level micro-nano structure on the fiber surface, thereby achieving a super-hydrophobic effect, while promoting the metal to generate a ceramic phase surface and strengthen the concrete. The granular material is laser-treated with ammonia, which can not only enhance the chemical stability of the material, but also facilitate the formation of a stable spatial structure of the hydration product, thereby enhancing the bonding strength between the geopolymer and the aggregate. In addition, a small amount of chromium in the metal can form a chemical bond with the polymer substance, further enhancing the mechanical properties of the matrix.

[0060] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A method for preparing high-strength permeable concrete, characterized in that: The following steps are involved: (1) Grind the steel slag until it passes through a 200-mesh sieve, pour it into an 8 wt% sulfuric acid solution, stir it at 200 rpm for 10-15 h, filter and wash it until the pH of the filtrate is 7, dry it, mix it with carbon powder, and perform a reduction treatment to obtain a refined powder; (2) Silica sol, refined powder, metal additive, polyvinyl pyrrolidone, and N,N-dimethylformamide are uniformly mixed and spun using a cross-shaped spinneret. The resulting fiber is then heated at 300-400°C under nitrogen protection for 5-8 hours, then heated to 800-1000°C and calcined for 0.5-2 hours to obtain a fiber material; (3) treating the fiber material with a laser in an oxygen atmosphere to obtain filler A; (4) Shearing the fiber material into a material with a particle size of 0.1 to 0.5 mm, and subjecting it to laser treatment in a liquid environment to obtain filler B; (5) 1 / 5 of the mass of deionized water was first mixed with melon stone, recycled aggregate with a particle size of 4.7 mm, and recycled aggregate with a particle size of 9.5 mm, and stirred at 60 rpm for 100 s. Filler A, filler B, polypropylene fiber, water-based epoxy resin, and 1 / 2 of the mass of deionized water were added and stirred for 100 to 200 s. The water reducer and the remaining deionized water were added, and finally stirred for 100 s to obtain high-strength permeable concrete.

2. The method for preparing high-strength permeable concrete according to claim 1, wherein: The chemical components of the steel slag in step (1) are as follows: 37.42% by weight of iron oxide, 31.98% by weight of calcium oxide, 12.63% by weight of silicon dioxide, 5.35% by weight of aluminum oxide, 5.32% by weight of magnesium oxide, 4.07% by weight of manganese oxide, 1.72% by weight of chromium oxide, and 1.17% by weight of others.

3. The method for preparing high-strength permeable concrete according to claim 1, wherein: The specific steps of the reduction treatment in step (1) are as follows: first, the slag is treated for 30 to 90 minutes under the conditions of a vacuum degree of 10 Pa and a temperature of 600 to 750° C., and then the iron is recovered. The remaining slag is further heated to 1200 to 1500° C. and treated for 30 to 90 minutes to obtain a partial reduction product. Finally, hydrogen is introduced and the temperature is raised to 1500 to 2000° C. and treated for 30 minutes to obtain a residual reduction product.

4. The method for preparing high-strength permeable concrete according to claim 1, wherein: The mass ratio of the steel slag, 8wt% sulfuric acid solution and carbon powder in step (1) is 10:80:1-3.

5. The method for preparing high-strength permeable concrete according to claim 1, wherein: The spinning rate in step (2) is 1000-1500 m / min.

6. The method for preparing high-strength permeable concrete according to claim 1, characterized in that: The mass ratio of the silica sol, refined powder, metal additive, polyvinyl pyrrolidone and N,N-dimethylformamide in step (2) is 1:0.5:0.05-0.1:0.2-0.4:0.

1.

7. The method for preparing high-strength permeable concrete according to claim 1, characterized in that: The metal auxiliary agent in step (2) is at least one of zirconium sulfate, aluminum chloride, titanium orthosulfate, magnesium sulfide, and tin chloride.

8. The method for preparing high-strength permeable concrete according to claim 1, wherein: The process conditions of the laser treatment in step (3) are as follows: power of 600 mW, pulse width of 40 fs, wavelength of 800-1100 nm, pulse frequency of 1 kHz, scanning speed of 1 mm / s, spacing of 60-120 μm, and ultrasonic power of 100 W.

9. The method for preparing high-strength permeable concrete according to claim 1, wherein: The process conditions of the laser treatment in step (4) are as follows: the auxiliary liquid is 5-30wt% ammonia solution, the power is 600mW, the scanning speed is 350mm / s, the number of scans is 5-10 times, the wavelength is 800-1100nm, the pulse width is 40fs, and the pulse frequency is 5-25kHz.

10. The method for preparing high-strength permeable concrete according to claim 1, characterized in that: The mass ratio of the melon stone, the recycled aggregate with a particle size of 4.7 mm, the recycled aggregate with a particle size of 9.5 mm, filler A, filler B, polypropylene fiber, water-based epoxy resin, water reducer and deionized water in step (5) is 250:70:70:0.5-2:0.1-0.5:0.1:3:1:40-50.