Pervious concrete and preparation method thereof

Abstract

The invention belongs to the technical field of concrete, and particularly relates to pervious concrete and a preparation method thereof. According to the invention, the ardealite aggregate is adopted to replace natural aggregate and is introduced into the pervious concrete material, and the ultra-thin slurry is used to bond the ardealite aggregate together to form the pervious concrete, so that the demand on natural resources is reduced, and the production cost of the pervious concrete is reduced; meanwhile, the problem of accumulation of phosphogypsum can be effectively relieved, and the resource utilization rate of phosphogypsum solid waste is increased. Compared with the existing common pervious concrete, the pervious concrete provided by the invention can further improve the water permeability and porosity on the basis of ensuring the mechanical strength and avoiding cracking.

Description

Technical Field

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

[0002] Phosphogypsum is a solid waste generated during the production of wet phosphoric acid. The wet process is economical, but it produces a large amount of phosphogypsum. For every ton of phosphoric acid produced, 4.5 to 5.5 tons of phosphogypsum will be produced. According to statistics, the global cumulative stockpile of phosphogypsum has exceeded 6 billion tons, and the cumulative stockpile in my country has reached 870 million tons, with an annual increase of about 80 million tons. It is mainly accumulated in the Yangtze River Economic Belt. There are many harmful impurities in phosphogypsum, such as phosphate, fluoride, sulfate ions and organic matter. This large-scale accumulation of phosphogypsum not only occupies a large amount of land resources, but also causes environmental pollution, causing serious impacts on the life and property safety of local residents. Therefore, it is particularly urgent and necessary to study the resource utilization of phosphogypsum solid waste. At present, the resource utilization of phosphogypsum is mainly reflected in the fields of agricultural fertilizers, soil improvement, road foundation materials and cement retarders. Although some progress has been made in these applications, the amount of phosphogypsum processed by these applications is relatively limited. Research shows that less than 15% of phosphogypsum is effectively recycled and utilized, while the remaining 85% is not treated and is piled up or landfilled as solid waste. This situation restricts the large-scale application of phosphogypsum and makes it difficult to overcome the technical difficulties of comprehensive utilization of phosphogypsum industrial waste residue.

[0003] Pervious concrete is a new type of building material with good permeability. It has been widely used in urban construction and environmental protection in recent years. Due to its unique permeable structure, pervious concrete can effectively reduce urban rainwater runoff, prevent floods, improve the permeability of urban green spaces and public spaces, and is conducive to groundwater recharge and ecological restoration. In the preparation process of pervious concrete, natural aggregates account for 70-80% of the total volume of its design mix, which is the largest volume proportion of pervious concrete materials. With the expansion of the production volume and application scope of pervious concrete, as well as the wide availability and cost-effectiveness of sand and gravel materials, the demand for natural aggregates has shown rapid growth, making the shortage of natural aggregates gradually evolve into an urgent problem facing the concrete industry. In addition, affected by the restrictions on natural aggregate mining by environmental protection policies and the continuous rise in aggregate prices, domestic and foreign researchers have begun to look for low value-added products as alternatives to natural aggregates. Summary of the invention

[0004] The purpose of the present invention is to provide a permeable concrete and a preparation method thereof. The permeable concrete provided by the present invention replaces natural aggregate with phosphogypsum aggregate, thereby reducing production costs, realizing resource utilization of phosphogypsum, and further improving the permeability and porosity of the permeable concrete.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a permeable concrete, comprising the following components in parts by weight:

[0007] 85-95 parts of cement, 20-30 parts of stone powder, 10-20 parts of silica fume, 1000-1200 parts of phosphogypsum aggregate, 110-130 parts of sand, 1-3 parts of water reducer and 20-30 parts of water;

[0008] The water-to-cement ratio of the permeable concrete is 0.2-0.23.

[0009] Preferably, the cement comprises silicate cement; the particle size of the cement is 0.275-79.433 μm, and the 28d strength is ≥48 MPa.

[0010] Preferably, the particle size of the stone powder is 0.363-13.183 μm; the particle size of the silica fume is 0.136-45.709 μm.

[0011] Preferably, the sand particles include first sand particles and second sand particles; the particle size of the first sand particles is 0.6-1.25 mm; the particle size of the second sand particles is 0.05-0.6 mm, excluding 0.6 mm;

[0012] The mass ratio of the first sand particles to the second sand particles is 15-25:60-90.

[0013] Preferably, the particle size of the phosphogypsum aggregate is 10.51-22.34 mm.

[0014] Preferably, the phosphogypsum aggregate comprises a phosphogypsum core and a persulfated phosphogypsum layer and a cement layer sequentially wrapped on the surface of the phosphogypsum core; the mass ratio of the phosphogypsum core, the persulfated phosphogypsum layer and the cement layer is 90-110:90-110:3-7.

[0015] Preferably, the preparation materials of the phosphogypsum core include original phosphogypsum, calcium oxide, cement clinker, mineral powder and residual slurry of electric poles, and the mass ratio of the original phosphogypsum, calcium oxide, cement clinker, mineral powder and residual slurry of electric poles is 85-90: 0.20-0.30: 2-6: 5.50-6.00: 1-3;

[0016] The preparation materials of the persulfated phosphogypsum layer include fine phosphogypsum, slag and cement clinker, and the mass ratio of the fine phosphogypsum, slag and cement clinker is 40-50:45-55:3-7;

[0017] The preparation materials of the cement layer include silicate cement and phosphogypsum cement, and the mass ratio of the silicate cement to the phosphogypsum cement is 50-60:40-50.

[0018] The present invention also provides a method for preparing the permeable concrete according to the above technical solution, comprising the following steps:

[0019] The components of the permeable concrete are mixed, and then molded and cured in sequence to obtain the permeable concrete.

[0020] Preferably, the mixing comprises:

[0021] Firstly mixing cement, lime, silica fume and sand to obtain a premix;

[0022] The premix, water reducing agent and water are mixed for the second time to obtain slurry;

[0023] The slurry and phosphogypsum aggregate are mixed for the third time.

[0024] Preferably, the curing temperature is 18-22° C., and the relative humidity is ≥95%.

[0025] The present invention provides a permeable concrete, comprising the following components by mass: 85-95 parts of cement, 20-30 parts of stone powder, 10-20 parts of silica fume, 1000-1200 parts of phosphogypsum aggregate, 110-130 parts of sand, 1-3 parts of water reducer and 20-30 parts of water; the water-cement ratio of the permeable concrete is 0.2-0.23. The present invention uses phosphogypsum aggregate to replace natural aggregate, incorporates it into the permeable concrete material, and uses ultra-thin slurry to cement the phosphogypsum aggregate together to form permeable concrete, which not only helps to reduce the demand for natural resources and reduce the production cost of permeable concrete, but also can effectively reduce the accumulation problem of phosphogypsum and improve the resource utilization rate of phosphogypsum solid waste. Compared with the currently commonly used permeable concrete, the permeable concrete provided by the present invention can further improve the permeability and porosity on the basis of ensuring mechanical strength and avoiding cracking. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a physical picture of the phosphogypsum aggregate provided by the present invention. DETAILED DESCRIPTION

[0027] The present invention provides a permeable concrete, comprising the following components in parts by weight:

[0028] 85-95 parts of cement, 20-30 parts of stone powder, 10-20 parts of silica fume, 1000-1200 parts of phosphogypsum aggregate, 110-130 parts of sand, 1-3 parts of water reducer and 20-30 parts of water;

[0029] The water-to-cement ratio of the permeable concrete is 0.2-0.23.

[0030] The permeable concrete provided by the present invention comprises 85 to 95 parts by mass of cement, more preferably 87 to 93 parts, and more preferably 89 to 91 parts. In the present invention, the cement preferably comprises silicate cement. In the present invention, the particle size of the cement is preferably 0.275 to 79.433 μm, more preferably 0.275 to 45.237 μm, and more preferably 7.692 to 25.538 μm; the 28d strength is preferably ≥48 MPa. In the present invention, the cement has high strength and fast coagulation and hardening.

[0031] The permeable concrete provided by the present invention comprises 20 to 30 parts by mass of stone powder, more preferably 23 to 27 parts. In the present invention, the particle size of the stone powder is preferably 0.363 to 13.183 μm, more preferably 0.363 to 8.183 μm, and more preferably 1.363 to 2.583 μm. In the present invention, the stone powder has high bonding strength and can increase the nucleation effect of the hydration product, providing sites for the crystal nucleus.

[0032] The permeable concrete provided by the present invention comprises 10 to 20 parts by mass of silica fume, more preferably 12 to 18 parts. In the present invention, the particle size of the silica fume is preferably 0.136 to 45.709 μm, more preferably 0.136 to 1.109 μm, and more preferably 0.136 to 0.307 μm. In the present invention, the activity of the silica fume is very high, and the silica fume can fill the pores inside the concrete, so that the active silicon dioxide can undergo a secondary reaction, thereby compacting the internal structure of the concrete.

[0033] The permeable concrete provided by the present invention includes 110 to 130 parts by mass of sand, more preferably 115 to 125 parts, and more preferably 117 to 123 parts. In the present invention, the sand preferably includes first sand and second sand. In the present invention, the particle size of the first sand is preferably 0.6 to 1.25 mm; the particle size of the second sand is preferably 0.05 to 0.6 mm, and 0.6 mm is not included. In the present invention, the mass ratio of the first sand to the second sand is preferably 15 to 25: 60 to 90, more preferably 17 to 23: 70 to 80, and more preferably 18 to 22: 72 to 77. In the present invention, the use of sand with the above-mentioned grading ratio can make the materials closely stacked.

[0034] The permeable concrete provided by the present invention comprises 1000 to 1200 parts by mass of phosphogypsum aggregate, more preferably 1050 to 1150 parts by mass. In the present invention, the particle size of the phosphogypsum aggregate is preferably 10.51 to 22.34 mm, more preferably 13.2 to 19.0 mm.

[0035] In the present invention, the phosphogypsum aggregate preferably includes a phosphogypsum core and a persulfated phosphogypsum layer and a cement layer sequentially wrapped on the surface of the phosphogypsum core; the mass ratio of the phosphogypsum core, the persulfated phosphogypsum layer and the cement layer is preferably 90-110:90-110:3-7.

[0036] In the present invention, the materials for preparing the phosphogypsum core preferably include original phosphogypsum, calcium oxide, cement clinker, mineral powder and pole slurry. The mass ratio of the original phosphogypsum, calcium oxide, cement clinker, mineral powder and pole slurry is preferably 85-90: 0.20-0.30: 2-6: 5.50-6.00: 1-3; further preferably 88: 0.26: 4: 5.74: 2.

[0037] In the present invention, the materials for preparing the persulfated phosphogypsum layer preferably include fine phosphogypsum, slag and cement clinker, and the mass ratio of the fine phosphogypsum, slag and cement clinker is preferably 40-50:45-55:3-7; more preferably 45:50:5.

[0038] In the present invention, the preparation material of the cement layer preferably includes Portland cement and phosphogypsum cement, and the mass ratio of the Portland cement to the phosphogypsum cement is preferably 50-60:40-50, and more preferably 55:45.

[0039] In the present invention, the preparation method of the phosphogypsum aggregate preferably comprises the following steps:

[0040] The original phosphogypsum, calcium oxide, cement clinker, mineral powder, residual slurry of electric poles and water are first mixed and granulated to obtain the phosphogypsum core;

[0041] The fine phosphogypsum, slag and cement clinker are mixed for the second time to obtain a persulfated phosphogypsum layer material;

[0042] The phosphogypsum core and the persulfated phosphogypsum layer material are thirdly mixed to obtain a core wrapped with the persulfated phosphogypsum layer;

[0043] The core wrapped with the persulfated phosphogypsum layer is fourthly mixed with silicate cement and phosphogypsum cement to obtain the phosphogypsum aggregate.

[0044] In the present invention, the mass of water in the first mixture is preferably 16.5% of the phosphogypsum core.

[0045] The present invention has no particular limitation on the processes of the first mixing, the second mixing, the third mixing and the fourth mixing, and they may be carried out using processes well known to those skilled in the art.

[0046] The permeable concrete provided by the present invention comprises 1 to 3 parts by weight of a water reducer, more preferably 1.5 to 2.5 parts by weight, and more preferably 2 parts by weight. In the present invention, the water reducer preferably comprises a polycarboxylate water reducer.

[0047] The permeable concrete provided by the present invention comprises 10 to 30 parts by mass of water, more preferably 22 to 28 parts by mass. In the present invention, the use of the above amount of water can make the slurry better bonded with the aggregate.

[0048] In the present invention, the water-cement ratio of the permeable concrete is 0.2-0.23, specifically 0.2, 0.21, 0.22, or 0.23.

[0049] The present invention also provides a method for preparing the permeable concrete according to the above technical solution, comprising the following steps:

[0050] The components of the permeable concrete are mixed, and then molded and cured in sequence to obtain the permeable concrete.

[0051] In the present invention, the mixing is preferably carried out in a stirring pot. In the present invention, the mixing preferably includes: first mixing cement, lime, silica fume and sand to obtain a premix; second mixing the premix with a water reducer and water to obtain a slurry; and third mixing the slurry with phosphogypsum aggregate.

[0052] In the present invention, the first mixing is preferably performed under stirring conditions; the stirring speed is preferably 130 to 140 rpm, more preferably 132 to 138 rpm, and more preferably 133 to 135 rpm; and the time is preferably 60 s.

[0053] In the present invention, the second mixing preferably includes first slow stirring, second slow stirring, standing and fast stirring in sequence. In the present invention, the speed of the first slow stirring is preferably 130-140 rpm, and the time is preferably 60 s; the speed of the second slow stirring is preferably 130-140 rpm, and the time is preferably 90 s; the standing time is preferably 70 s; the speed of the fast stirring is preferably 275-285 rpm, and the time is preferably 80 s.

[0054] In the present invention, the third mixing is preferably carried out under stirring conditions; the stirring speed is preferably 130-140 rpm; and the stirring time is preferably 60 s.

[0055] In the present invention, the molding preferably includes: pouring the mixed slurry aggregate into a mold, compacting it on a vibration table and coating the surface, and removing the mold after leaving it at room temperature for 24 hours.

[0056] In the present invention, the curing temperature is preferably 18-22°C, more preferably 19-21°C, and more preferably 20°C; the relative humidity is preferably ≥95%. In the present invention, the curing ages are preferably 3d, 7d, and 28d, respectively.

[0057] The present invention has no particular limitation on the curing process, and the curing process may be carried out using a process well known to those skilled in the art.

[0058] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0059] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] Embodiments 1 to 4

[0061] The original phosphogypsum, calcium oxide, cement clinker, mineral powder, residual slurry of electric poles and water are first mixed and granulated to obtain a phosphogypsum core; wherein the mass ratio of the original phosphogypsum, calcium oxide, cement clinker, mineral powder and residual slurry of electric poles is 88:0.26:4:5.74:2; and the amount of water added is 16.5% of the phosphogypsum core;

[0062] The fine phosphogypsum, slag and cement clinker are mixed for the second time to obtain a persulfated phosphogypsum layer material; wherein the mass ratio of the fine phosphogypsum, slag and cement clinker is 45:50:5;

[0063] The phosphogypsum core and the persulfated phosphogypsum layer material are thirdly mixed to obtain a core wrapped with the persulfated phosphogypsum layer;

[0064] The core wrapped with the persulfated phosphogypsum layer is mixed with silicate cement and phosphogypsum cement to obtain the phosphogypsum aggregate (particle size is 13.2-19.0 mm); wherein the mass ratio of silicate cement to phosphogypsum cement is 55:45; and the mass ratio of the phosphogypsum core, the persulfated phosphogypsum layer and the cement layer is 100:100:5;

[0065] Prepare permeable concrete according to the raw material ratio in Table 1;

[0066] Put cement (OPC, particle size of 7.692-25.538 μm, 28d strength ≥48 MPa), stone powder (LP, particle size of 1.363-2.583 μm), silica fume (SF, particle size of 0.136-0.307 μm) and sand (wherein the particle size of the first sand is 0.6-1.25 mm, and the particle size of the second sand is 0.15-0.6 mm, excluding 0.6 mm) in a stirring pot, and stir at a speed of 130 rpm for 60 seconds to obtain a premix;

[0067] Adding polycarboxylate water-reducing agent (SP) and water to the premix, stirring at a speed of 130 rpm for 60 seconds, stirring at a speed of 130 rpm for 90 seconds after slurry is formed, standing for 70 seconds, and stirring at a speed of 275 rpm for 80 seconds to obtain slurry;

[0068] Adding phosphogypsum aggregate into the slurry, stirring at a rotation speed of 130 rpm for 60 seconds to obtain slurry aggregate;

[0069] The mixed slurry aggregate is poured into a mold, compacted on a vibration table and coated on the surface, and then removed from the mold after being left at room temperature for 24 hours;

[0070] The test blocks after demolding are placed in a standard curing room for curing, wherein the temperature of the curing room is 20±2° C., the relative humidity is ≥95%, and the curing ages are 3d, 7d and 28d, respectively, to obtain the permeable concrete.

[0071] Table 1 Raw material ingredients list of Examples 1 to 4 (parts)

[0072] OPC LP SF First sand Second sand grain Phosphogypsum aggregate SP water Water-cement ratio Example 1 90.0 24.0 17.3 26.4 92.4 1050 2.16 24.9 0.20 Example 2 90.0 24.0 17.3 26.4 92.4 1050 2.16 26.2 0.21 Example 3 90.0 24.0 17.3 26.4 92.4 1050 2.16 27.5 0.22 Example 4 90.0 24.0 17.3 26.4 92.4 1050 2.16 28.8 0.23

[0073] Performance Testing

[0074] Test Example 1

[0075] The permeable concrete obtained in Examples 1 to 4 was prepared into a test piece with a size of 100mm*100mm*100mm, and the compressive strength test was carried out in accordance with the "Standard for Test Methods for Physical and Mechanical Properties of Concrete" (GB / T50081-2019). The compressive strength of Example 1 was measured to be 19.71Mpa after 28 days of curing, the compressive strength of Example 2 was measured to be 14.03Mpa after 28 days of curing, the compressive strength of Example 3 was measured to be 10.47Mpa after 28 days of curing, and the compressive strength of Example 4 was measured to be 5.41Mpa after 28 days of curing, all of which met the strength requirements of permeable concrete. It can be seen from the above data that the present invention uses ultra-thin slurry and large-size phosphogypsum aggregate to prepare permeable concrete, and the obtained permeable concrete can ensure compressive strength on the basis of ultra-thin slurry.

[0076] Test Example 2

[0077] The permeable concrete obtained in Examples 1 to 4 was prepared into test pieces with a size of 100 mm*100 mm*100 mm, and the permeability coefficient was tested in accordance with "Permeable Concrete" (JC / T2558-2020).

[0078] The water permeability coefficient test should be carried out according to the following steps:

[0079] The specimens to be tested for water permeability coefficient shall be taken out from the standard curing room at the curing age of 27 days, and then immersed in (20±2)℃ water. The water surface shall be 20mm~30mm higher than the upper surface of the specimens during immersion. The immersion time shall be 24h. The specimens shall be tested for water permeability coefficient at the age of 28 days.

[0080] The specimens that have reached the age are measured with a steel ruler for the length, width and thickness of the upper surface of the cubic specimens. The measurements are respectively taken twice, and the average value is taken, accurate to 1mm, and the upper surface area of ​​the specimens is calculated. Then, the specimens are loaded into the prism sealing device, and the water supply valve is opened to allow water to enter the container. The water inlet is adjusted to keep the prism sealing device at a certain water level (about 150mm). After the water outflow from the overflow port of the prism sealing device is stable, water is collected from the water outlet with a measuring container, and the water outflow in 90s is recorded. The measurement is performed three times and the average value is taken;

[0081] Use a steel ruler to measure the difference between the water level in the prism seal and the water level on the upper surface of the test piece to an accuracy of 1 mm. Use a thermometer to measure the temperature of the water in the prism seal during the test to an accuracy of 1°C.

[0082] After testing, the water permeability coefficient of Example 1 after curing for 28 days is 6.27 mm / s, the water permeability coefficient of Example 2 after curing for 28 days is 9.20 mm / s, the water permeability coefficient of Example 3 after curing for 28 days is 15.78 mm / s, and the water permeability coefficient of Example 4 after curing for 28 days is 20.08 mm / s, all of which belong to permeable concrete. It can be seen from the above data that the present invention uses ultra-thin slurry and large-size phosphogypsum aggregate to prepare permeable concrete, and the permeable concrete obtained can have a water permeability coefficient far greater than the requirements of the regulations on the basis of ultra-thin slurry.

[0083] Test Example 3

[0084] The permeable concrete obtained in Examples 1 to 4 was prepared into test pieces with a size of 100 mm*100 mm*100 mm, and a continuous porosity test was performed in accordance with the Technical Specification for Permeable Cement Concrete Pavement (CJJ / T 135-2009).

[0085] The continuous porosity determination test should be carried out according to the following steps:

[0086] Soak the specimen in 20℃ water, take it out and drain it after 24 hours, measure the length, width and height of the specimen to an accuracy of 1mm, and calculate the volume of the specimen;

[0087] Move the specimen into a bucket and weigh the suspended mass of the specimen to an accuracy of 1g;

[0088] Take out the specimen and place it in a standard curing room to drain. When there is no water dripping from the bottom of the specimen, weigh the mass of the specimen to an accuracy of 1g.

[0089] After testing, the continuous porosity of Example 1 after curing for 28 days is 13.67%, the continuous porosity of Example 2 after curing for 28 days is 17.08%, the continuous porosity of Example 3 after curing for 28 days is 23.81%, and the continuous porosity of Example 4 after curing for 28 days is 30.45%, which belongs to permeable concrete. It can be seen from the above data that the present invention uses ultra-thin slurry and large-size phosphogypsum aggregate to prepare permeable concrete, and the obtained permeable concrete can be tightly bonded under the action of ultra-thin slurry, so that the porosity is increased, and the continuous porosity is much greater than the requirements of the regulations.

[0090] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A permeable concrete, characterized in that: The composition includes the following components in parts by weight: 85-95 parts of cement, 20-30 parts of stone powder, 10-20 parts of silica fume, 1000-1200 parts of phosphogypsum aggregate, 110-130 parts of sand, 1-3 parts of water reducer and 20-30 parts of water; The water-to-cement ratio of the permeable concrete is 0.2-0.

23.

2. The permeable concrete according to claim 1, characterized in that: The cement comprises silicate cement; the particle size of the cement is 0.275-79.433 μm, and the 28d strength is ≥48 MPa.

3. The permeable concrete according to claim 1, characterized in that: The particle size of the stone powder is 0.363-13.183 μm; the particle size of the silica fume is 0.136-45.709 μm.

4. The permeable concrete according to claim 1, characterized in that: The sand particles include first sand particles and second sand particles; the particle size of the first sand particles is 0.6 to 1.25 mm; the particle size of the second sand particles is 0.05 to 0.6 mm, excluding 0.6 mm; The mass ratio of the first sand particles to the second sand particles is 15-25:60-90.

5. The permeable concrete according to claim 1, characterized in that: The particle size of the phosphogypsum aggregate is 10.51-22.34 mm.

6. The permeable concrete according to claim 1 or 5, characterized in that: The phosphogypsum aggregate comprises a phosphogypsum core and a persulfated phosphogypsum layer and a cement layer which are sequentially wrapped on the surface of the phosphogypsum core; the mass ratio of the phosphogypsum core, the persulfated phosphogypsum layer and the cement layer is 90-110:90-110:3-7.

7. The permeable concrete according to claim 6, characterized in that: The materials for preparing the phosphogypsum core include original phosphogypsum, calcium oxide, cement clinker, mineral powder and residual slurry of electric poles, and the mass ratio of the original phosphogypsum, calcium oxide, cement clinker, mineral powder and residual slurry of electric poles is 85-90: 0.20-0.30: 2-6: 5.50-6.00: 1-3; The preparation materials of the persulfated phosphogypsum layer include fine phosphogypsum, slag and cement clinker, and the mass ratio of the fine phosphogypsum, slag and cement clinker is 40-50:45-55:3-7; The preparation materials of the cement layer include silicate cement and phosphogypsum cement, and the mass ratio of the silicate cement to the phosphogypsum cement is 50-60:40-50.

8. The method for preparing permeable concrete according to any one of claims 1 to 7, characterized in that: The following steps are involved: The components of the permeable concrete are mixed, and then molded and cured in sequence to obtain the permeable concrete.

9. The preparation method according to claim 8, characterized in that: The mixing includes: Firstly mixing cement, lime, silica fume and sand to obtain a premix; The premix, water reducing agent and water are mixed for the second time to obtain slurry; The slurry and phosphogypsum aggregate are mixed for the third time.

10. The preparation method according to claim 8, characterized in that: The curing temperature is 18-22° C., and the relative humidity is ≥95%.

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