Preparation method of sand-based microporous permeable surface layer material

Abstract

The invention provides a preparation method of a sand-based microporous water-permeable surface layer material, which comprises the following steps: uniformly mixing an adhesive and a curing agent according to a mass ratio of 5: 1, adding the mixture into a stirrer, jointly stirring the mixture with a filler, a hydrophilic auxiliary agent and aggregate, uniformly stirring to obtain a mixture, loading the mixture into a mold, curing at room temperature for 24 hours, demolding, and drying in a drying oven to obtain the sand-based microporous water-permeable surface layer material. The sand-based microporous permeable surface layer material is obtained; the adhesive is formed by mixing E51 epoxy resin and a diluent XY-215 according to a mass ratio; the curing agent is formed by mixing modified polyether amine UR6088 and polyether amine D230 according to the mass ratio of 4: 5; the filler is glass powder, quartz powder or nano silicon dioxide; the hydrophilic auxiliary agent is Tween T20; the aggregate is 10-70-mesh snowflake white sand, chicken blood red sand or washed river sand. The sand-based microporous permeable surface layer material prepared by the invention has comprehensive mechanical strength characteristics, can be used in various working condition environments, and is relatively long in service life.

Description

Technical Field

[0001] This invention belongs to the field of concrete technology, specifically relating to a method for preparing a sand-based microporous permeable surface material. Background Technology

[0002] To optimize the urban ecological environment and promote the construction of "sponge cities," various permeable pavement materials, such as permeable concrete and permeable bricks, have been introduced to the market. However, ordinary cement-based permeable pavement materials often suffer from problems such as pore blockage, surface cracking, surface efflorescence, and unsatisfactory permeability due to their large pores and the characteristics of cement-based materials. To address these issues, domestic and international scholars have successfully applied epoxy resin, which has been successfully used in engineering, to permeable pavements, developing an environmentally friendly, eco-friendly sand-based microporous permeable material with strong filtration capacity, resistance to clogging, and high strength. This material uses a two-component epoxy resin as an adhesive and natural colored sand or aeolian sand as aggregate. The aggregate particles have a spacing between tens to hundreds of micrometers, which can filter suspended particles and large blockages in the flowing liquid onto the material surface to prevent pore blockage. It has advantages such as high strength, good toughness, cooling and sound absorption, and rich colors. Currently, many researchers mainly study the mechanical properties of pavement materials, while there is relatively little analysis and research on the mechanical changes after long-term hydrothermal aging based on simulated actual application scenarios. Microporous permeable pavement layers are subjected to various environmental conditions over long periods, including ultraviolet radiation, temperature fluctuations, humid and hot environments, wet-dry cycles, and rainwater soaking. The combined effects of temperature and humidity can cause material performance degradation, leading to internal hygrothermal stress, loss of adhesive layer strength, and, with accumulated internal damage, aggregate detachment and breakage, significantly reducing their service life. Therefore, there is an urgent need to develop a sand-based microporous permeable pavement material that can be used under these diverse environmental conditions and has a long service life. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for preparing a sand-based microporous permeable surface material in view of the shortcomings of the prior art. The sand-based microporous permeable surface material prepared by this method has significantly increased mechanical strength under hydrothermal conditions.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a sand-based microporous permeable surface material. The preparation method is as follows: an adhesive and a curing agent are mixed evenly at a mass ratio of 5:1, and then added to a mixer and stirred together with fillers, hydrophilic additives, and aggregates. After being stirred evenly, a mixture is obtained. The mixture is poured into a mold, cured at room temperature for 24 hours, demolded, and then placed in an oven to dry, thereby obtaining the sand-based microporous permeable surface material. The adhesive is composed of E51 epoxy resin and diluent XY-215 mixed at a mass ratio; the curing agent is composed of modified polyetheramine UR6088 and polyetheramine D230 mixed at a mass ratio of 4:5; the filler is glass powder, quartz powder, or nano-silica; the hydrophilic additive is electrostatic conductive agent AT-46 or Tween T20; and the aggregate is 20-40 mesh snowflake white sand, blood-red sand, or washed river sand.

[0005] Preferably, after the mixture is loaded into the mold, the specimen is formed by layering and manual compaction to ensure the density of the aggregate. The mass error of the mixture in each mold does not exceed 5%. The specimen is cured at room temperature of 20±2℃ for 24 hours, then demolded and placed in an oven at 70℃ for 24 hours.

[0006] Preferably, the modified polyetheramine UR6088 is slowly poured into polyetheramine D230, stirred and mixed evenly, and then placed in a vacuum drying oven, vacuumed to below -0.095 MPa, and kept for 5-10 minutes. The bubbles inside the curing agent rapidly expand and rise to the surface and rupture to obtain the curing agent.

[0007] Preferably, the amount of adhesive used is 5% of the aggregate mass.

[0008] Preferably, the hydrophilic additive is Tween T20, and the amount of the hydrophilic additive is 1.67% of the adhesive mass.

[0009] Preferably, the filler is glass powder, and the amount of glass powder used is 30%-40% of the adhesive mass.

[0010] Compared with the prior art, the present invention has the following advantages: 1. This invention prepares a sand-based microporous permeable surface material with high efficiency, excellent water permeability, and excellent hydrothermal resistance. By optimizing the raw material formulation and dosage ratio, the adhesive and curing agent are mixed evenly at a mass ratio of 5:1. After being added to a mixer, the mixture is stirred together with filler, hydrophilic additive, and aggregate. After being stirred evenly, a mixture is obtained. The mixture is poured into a mold, cured at room temperature for 24 hours, demolded, and then dried in an oven to obtain the sand-based microporous permeable surface material. The adhesive is selected from 51 epoxy resin and diluent XY-215 mixed at a mass ratio. The curing agent is composed of modified polyetheramine UR6088 and polyetheramine D230 mixed at a mass ratio of 4:5. The filler is glass powder, quartz powder, or nano-silica. The hydrophilic additive is Tween T20. The aggregate is 20-40 mesh snowflake white sand, chicken blood red sand, or washed river sand. The sand-based microporous permeable surface material prepared by this invention exhibits balanced compressive and flexural strength under wet and dry aging conditions, and can have a long service life under various working conditions such as temperature alternation, humid and hot environments, wet and dry cycles, and rainwater immersion.

[0011] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0012] Example 1 This embodiment discloses a method for preparing a sand-based microporous permeable surface layer material. The preparation method is as follows: S1. Slowly pour modified polyetheramine UR6088 into polyetheramine D230, stir and mix evenly, then place in a vacuum drying oven, evacuate to below -0.095 MPa, and maintain for 5-10 minutes. The air bubbles inside the curing agent rapidly expand and rise to the surface and rupture, obtaining the curing agent (marked as composite MCC). Its appearance is a colorless to light yellow transparent liquid. Testing shows that the viscosity of composite MCC at 25℃ is... The amine value is 400-500 mg KOH / g.

[0013] S2. The adhesive and curing agent are mixed evenly at a mass ratio of 5:1. After being added to the mixer, they are mixed together with the filler, hydrophilic additives and aggregates. After being mixed evenly, a mixture is obtained. The mixture is then filled into a mold. The specimen is formed by layering and manually compacting to ensure the density of the aggregate. The mass error of the mixture in each mold does not exceed 5%. The specimen is cured at room temperature of 20±2℃ for 24 hours, then demolded and placed in an oven at 70℃ for 24 hours to obtain a sand-based microporous permeable surface material specimen.

[0014] In this embodiment, the adhesive is a mixture of E51 epoxy resin and diluent XY-215 in a certain mass ratio; the amount of adhesive used is 5% of the aggregate mass.

[0015] In this embodiment, the curing agent is a mixture of modified polyetheramine UR6088 and polyetheramine D230 in a mass ratio of 4:5; the filler is glass powder, and the amount of glass powder is 30% of the mass of the adhesive.

[0016] In this embodiment, the hydrophilic additive is Tween T20, and the amount of the hydrophilic additive is 1.67% of the adhesive mass.

[0017] In this embodiment, the aggregate is 20-40 mesh snowflake white sand. The filler is glass powder, and the amount of glass powder used is 30%-40% of the adhesive mass.

[0018] Example 2 In this embodiment, the preparation method is the same as in Example 1, except that the curing agent is curing agent TS-100 (blank group), curing agent 6036, curing agent 6088, or similar commercially available curing agent WH; the main component of curing agent TS-100 is a mixed modified amine, and its viscosity at 25°C is [missing information]. The amine value is 290±20 mgKOH / g, and the appearance is a water-white transparent liquid, purchased from Shanghai Junjiang Technology Co., Ltd.; the main component of curing agent 6036 is a modified alicyclic amine, and the viscosity at 25℃ is... The amine value is 450±30 mgKOH / g, and the appearance is a colorless or pale yellow liquid, purchased from Changzhou Yourui Polymer Materials Co., Ltd.; the main component of curing agent 6088 is modified polyether amine, and the viscosity at 25℃ is... The amine value is 400±10 mg KOH / g, and the viscosity at 25℃ is... The amine value is 400-500 mg KOH / g, and the appearance is a colorless or pale yellow liquid, purchased from Changzhou Yourui Polymer Materials Co., Ltd.; the main component of the curing agent WH is polyether amine, and the viscosity at 25℃ is... It has an amine value of 350±10 mgKOH / g and appears as a colorless or pale yellow liquid.

[0019] The sand-based microporous permeable surface materials prepared in Examples 1 and 2 were subjected to hydrothermal aging tests. The hydrothermal aging was divided into humid heat conditions and wet-dry cycle conditions. The specific scheme was as follows: flexural and compressive strength tests were conducted under humid heat conditions, specifically: the samples were treated with a 70℃ water bath for 7 days; the wet-dry cycle conditions consisted of drying at 50℃ for 6 hours and then a 70℃ water bath for 18 hours, which was one wet-dry cycle, and 7 cycles were performed for 7 days; after 7 days of hydrothermal aging, the samples were placed in a 50℃ oven for 24 hours, and the flexural and compressive strength tests were conducted on the samples. The blank group samples were tested at the same age as the hydrothermally aged samples.

[0020] Mechanical performance testing: Refer to GB / T17671-2021 "Test method for strength of cement mortar (ISO method)".

[0021] Table 1. Flexural strength data of specimens prepared with different types of curing agents Table 2. Flexural strength data of specimens prepared with different types of curing agents The data in Tables 1 and 2 show that under the combined effects of hydrothermal and wet-dry cycles, the epoxy resin adhesive ages as the hydrothermal time increases and the number of wet-dry cycles increases. This leads to a decrease in the mechanical properties of the adhesive material and a reduction in aggregate bonding strength, resulting in a decrease in strength after hydrothermal-wet-dry cycles. Overall, the composite curing agent exhibits a more balanced retention rate of flexural and compressive strength after hydrothermal aging compared to the other four curing agents, and both are higher than the market-market product WH resin. Therefore, the composite MCC curing agent will be used for subsequent tests.

[0022] Under humid and hot conditions and wet-dry cycle conditions, 6088 exhibits a high strength retention rate, with flexural and compressive strength retention rates reaching approximately 65% ​​and 95% respectively under wet-dry cycle conditions. Composite MCC is second best, with flexural and compressive strength retention rates reaching approximately 70% and 80% respectively under wet-dry cycle conditions.

[0023] Example 3 In this embodiment, the preparation method is the same as that in Example 1, except that the amount of adhesive used is 3%, 4%, 7%, 9% or 11% of the aggregate mass.

[0024] The sand-based microporous permeable surface materials prepared in Examples 1 and 3 were subjected to hydrothermal aging tests, and the test methods were the same as those disclosed in Example 2.

[0025] Table 3. Flexural strength data of specimens prepared with different adhesive dosages Table 4. Flexural strength data of specimens prepared with different adhesive dosages The data in Tables 3 and 4 show that: (1) With the increase of adhesive dosage, the strength of the specimens under the three conditions showed a trend of rapid increase followed by gradual slowdown. In the range of 3% to 7% adhesive dosage, the strength showed a significant increasing trend with the increase of adhesive dosage, with flexural and compressive strength increasing from 5.0 MPa to 8.48 MPa and from 12.12 MPa to 23.73 MPa, respectively. When the adhesive dosage exceeded 7%, the strength growth rate slowed down, especially in the range of 9% to 11% adhesive dosage, where the strength growth trend slowed down significantly, with flexural and compressive strength increasing from 8.48 MPa to 10.40 MPa and from 23.73 MPa to 28.92 MPa, respectively. The reason for this phenomenon is as follows: when the amount of adhesive is small, it is insufficient to cover the surface of the aggregate, resulting in poor adhesion between the aggregates and naturally lower strength; subsequently, as the amount of adhesive increases, the sand particles are gradually wetted and coated, and the bonding force between the two interfaces gradually increases, which increases the energy required to break the bonding force, and the strength gradually increases; when the amount of adhesive exceeds a certain amount, the excess adhesive flows downward under the action of gravity and fills the pores, contributing little to the increase in strength.

[0026] (2) With the increase of adhesive dosage, the strength retention rate of the specimens under the three conditions showed a trend of first rapid increase and then gradual flattening. When the adhesive dosage was in the range of 3% to 5%, the strength retention rate showed a rapid increase. The flexural and compressive strength retention rates under wet heat aging increased from 72.60% to 77.56% and from 78.8% to 84.83%, respectively; the flexural and compressive strength retention rates under wet-dry cycling increased from 65.00% to 71.79% and from 72.23% to 79.15%, respectively. With adhesive dosage ranging from 5% to 11%, the strength retention rate maintained a gradual upward trend. Under wet and heat aging, the flexural and compressive strength retention rates increased from 77.56% to 80.87% and from 84.83% to 88.55%, respectively. Under wet and dry cycling, the flexural and compressive strength retention rates increased from 71.79% to 74.04% and from 79.15% to 78.85%, respectively.

[0027] (3) The reason is that as the amount of adhesive increases, the adhesive coating thickness at the bonding interface between aggregate and adhesive increases, which in turn leads to a slight increase in the strength retention rate under humid heat conditions and dry-wet cycle aging conditions. This is consistent with Cao Ganghao's

[32] experiment on epoxy resin concrete, in which he found by electron microscopy of the bonding interface that as the amount of resin increases, the thickness of the aggregate surface increases. When the amount of resin increases from 4% to 8%, the thickness of the bonding zone gradually increases from the initial 17.10 μm to 44.15 μm. At this point, further increasing the amount of adhesive can only increase the resin film thickness on the surface of silica sand, and has no significant effect on improving the bonding force between the two interfaces. Example 4 In this embodiment, the preparation method is the same as that in Example 1, except that different raw materials and amounts of filler are used, as shown in Table 5. The flexural and compressive strength data of the specimens are tested using the hydrothermal aging test method disclosed in Example 2.

[0028] Table 5. Flexural and compressive strength data of specimens prepared with different fillers. As can be seen from the data in Table 5, (1) The effects of glass powder and quartz powder on the mechanical properties of the specimens were consistent, while the effect of nano-silica on the mechanical properties of the specimens was not as good as the former two. From the strength change curves of glass powder and quartz powder, it can be seen that the strength of the specimens increased with the increase of filler content. When the content of glass powder increased from 0% to 30%, the flexural and compressive strengths increased from 6.65MPa to 8.10MPa and from 16.06MPa to 18.73MPa, respectively. The change pattern of quartz powder was basically the same, and both were higher than the blank group without filler. The addition of filler has a positive effect on improving mechanical properties. When the content of nano-silica increased from 5% to 15%, the strength showed a trend of first increasing and then decreasing. When the content was 10%, the compressive strength was the highest at 16.86MPa and the flexural strength was 7.80MPa. It can be seen that there is an optimal range for the content of filler. The reason is that nanoparticles can form chemical bonds with epoxy resin, and absorb some of the energy in the resin matrix during the pressure process of the permeable material, thus inhibiting or eliminating the diffusion of microcracks in the resin.

[0029] (2) As the amount of quartz powder and glass powder increased from 0% to 30%, the mechanical properties of the specimens gradually improved. The flexural strength increased from 6.65 MPa to about 8 MPa, and the compressive strength increased from 16.36 MPa to about 18.5 MPa. This is because the filler has a good thickening effect, which enables the adhesive to adhere efficiently to the surface of the aggregate during the mixing process, increasing the bonding strength and thus increasing the compressive strength of the specimen. The adhesive without filler is in a relatively fluid state. During the stirring process, the adhesive can only adhere to a thin layer on the surface of the aggregate. When the specimen is under load, only this thin layer of adhesive peels off from the aggregate, and then the specimen is destroyed.

[0030] (3) Analysis: Inorganic fillers can improve the bonding properties of epoxy adhesives, reduce the cohesive forces between adhesive molecules, and increase the adhesive strength. Adding a certain amount of filler to the adhesive increases its viscosity, making it easier to coat the aggregate surface during stirring, and the degree of coating is higher than that without filler. At the same time, adding filler improves the viscosity and toughness of the adhesive itself to a certain extent, which is macroscopically manifested as an increase in the strength of the specimen.

[0031] Example 5 In this embodiment, the preparation method is the same as that in Example 1, except that different amounts of glass powder are used as fillers, as shown in Table 6. The flexural and compressive strength data of the specimens are tested using the hydrothermal aging test method disclosed in Example 2, and the data in Tables 6 and 7 are obtained.

[0032] Table 6. Compressive strength data of specimens prepared with different amounts of glass powder. Table 7. Flexural strength data of specimens prepared with different amounts of glass powder. As can be seen from Tables 6 and 7, (1) With a fixed amount of adhesive, the strength of the specimens first increased and then decreased as the amount of glass powder was gradually increased. Under blank conditions, in the range of 0%–40% increase, the strength of the specimens increased rapidly with the increase of glass powder, with flexural and compressive strengths increasing from 6.65 MPa to 7.78 MPa and from 16.36 MPa to 21.48 MPa, respectively. In the range of 40%–100%, the strength decreased with the increase of glass powder, with flexural and compressive strengths decreasing from 7.78 MPa to 5.33 MPa and from 21.48 MPa to 15.64 MPa, respectively. This is because when the amount of filler is low, the filler powder particles are more evenly dispersed in the adhesive, increasing the contact area between the filler and the adhesive matrix. The bonding effect between the two is greatly improved, and the interfacial bonding ability between the filler and the adhesive is strengthened. Macroscopically, this improves the adhesive performance of the adhesive and enhances the mechanical properties of the specimens. However, as the filler particle content increases, the powder particles agglomerate in the adhesive, resulting in uneven dispersion and a decrease in the strength of the microporous permeable surface layer.

[0033] (2) The strength retention rate is not strongly correlated with the amount of glass powder used; under humid and hot conditions, the flexural strength retention rate is about 75%, and the compressive strength retention rate is about 85%; under wet and dry cycling conditions, the flexural strength retention rate is in the range of 65%-70%, and the compressive strength retention rate is in the range of 75%-80%. This is because, under different glass powder dosages, within a certain aging period, moisture will cause the adhesive to age and crack, and then seep into the bonding interface through the cracks, causing damage.

[0034] Example 6 In this embodiment, the preparation method is the same as that in Example 1, except that different amounts of Tween-20 are used as filler, as shown in Table 9. The flexural and compressive strength data of the specimens are tested using the hydrothermal aging test method disclosed in Example 2, as shown in Tables 8 and 9.

[0035] Table 8. Flexural strength data of specimens prepared with different dosages of Tween-20 Table 9. Compressive strength data of specimens prepared with different dosages of Tween-20 This invention increases the amount of Tween-20 to graft the hydroxyl groups of the nonionic surfactant onto one end of the epoxy resin molecule to form an ether bond, thereby fixing the hydrophilic group as a side chain on the resin. This results in good hydrophilicity of the resin adhesive and reduces the contact angle of the adhesive surface.

[0036] The data disclosed in Tables 8 and 9 show that: With the gradual increase of the dosage of the hydrophilic additive Tween-20, the specimen strength and strength retention rate both showed a trend of first remaining stable and then gradually decreasing. Within the range of 0%–1.67% Tween-20 dosage increase, the small increase in Tween-20 had little effect on specimen strength, with a slight decrease in strength; flexural strength was between 7.53 MPa and 7.8 MPa, and compressive strength was between 21.48 MPa and 22.65 MPa. However, within the range of 3.33%–13.33% Tween-20 dosage increase, the effect of increasing Tween-20 on specimen strength became apparent, with a significant and larger decrease in strength; flexural strength decreased from 7.53 MPa to 4.6 MPa, and compressive strength decreased from 16.68 MPa to 12.12 MPa.

[0037] Within the range of 0%–13.33% increase in Tween-20 dosage, the effect of increasing Tween-20 on the strength retention rate after wet-heat and dry-wet cycling showed a decreasing trend. Under wet-heat conditions, the flexural and compressive strength retention rates decreased from 76.48% to 70.65% and from 82.83% to 73.14%, respectively; under dry-wet cycling conditions, the flexural and compressive strength retention rates decreased from 70.44% to 69.78% and from 77.98% to 61.74%, respectively.

[0038] Example 7 In this embodiment, the preparation method is the same as that in Example 1, except that the aggregate is 20-40 mesh chicken blood red sand or washed river sand, and the flexural and compressive strength data of the specimens are tested using the hydrothermal aging test method disclosed in Example 2, as shown in Tables 8 and 9.

[0039] Table 10 Flexural strength data of specimens prepared with different aggregates Table 11 Compressive strength data of specimens prepared with different aggregates The data in Tables 10 and 11 show that: (1) The strength of washed river sand is slightly higher, with flexural and compressive strengths of 11.40 MPa and 22.13 MPa, respectively; the flexural and compressive strengths of snowflake white sand and chicken-blood red sand are relatively close, at about 8.10 MPa and 20.70 MPa, respectively. After wet-heat and dry-wet cycles, the strength retention rate of washed river sand is the highest, followed by snowflake white sand and chicken-blood red sand.

[0040] (2) The reason why the mechanical properties of the three materials are relatively similar under blank conditions may be that the parent rocks of the three materials are all silica-based stones, and their stone properties are not significantly different. However, after hydrothermal aging, the significant difference in the strength retention rate of the three materials is due to the water absorption rate of their parent rocks. In the weak layer of the adhesive interface between epoxy resin and aggregate, water seeps in. If the aggregate is a material with high water absorption rate and high porosity, it will further absorb water and seep in, causing the adhesive interface to lose adhesive strength.

[0041] In this embodiment, the flexural and compressive strength data of specimens prepared from snowflake white sand with different particle sizes were also studied, as shown in Tables 12 and 13.

[0042] Table 12 Flexural strength data of specimens prepared from snowflake white sand of different particle sizes Table 13 Compressive strength data of specimens prepared from snowflake white sand of different particle sizes From the data in Tables 12 and 13 above, we can see that: (1) With a fixed amount of adhesive, the strength of the microporous permeable surface layer gradually increases as the aggregate particle size decreases. The possible reason for the above phenomenon is that, under the same volume, the reduction of aggregate particle size will increase the specific surface area of ​​the aggregate, which will increase the bonding surface between coarse sand and adhesive, resulting in more contact points, increased friction, and reduced porosity. Under external loads, the resistance is enhanced and the compressive strength is improved.

[0043] (2) However, as the particle size decreases to 70-140 mesh sand, the strength tends to decrease. The reason is that in the particle size range of 20-200 mesh, the compressive strength of 20-40 mesh and 40-70 mesh samples is relatively high. The aeolian sand of 70-200 mesh has finer particles and less mechanical interlocking force between particles. At the same time, the specific surface area of ​​sand particles increases as the aggregate mesh size decreases. When the amount of adhesive is constant, the thickness of the adhesive film decreases and the bonding effect between sand particles weakens, which will affect the strength.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a sand-based microporous permeable surface material, characterized in that, The preparation method is as follows: the adhesive and curing agent are mixed evenly according to the mass ratio of 5:1, and then added to the mixer and mixed together with filler, hydrophilic additives and aggregates. After the mixture is evenly mixed, the mixture is put into the mold, cured at room temperature for 24 hours, demolded, and then placed in the oven to dry to obtain sand-based microporous permeable surface material. The adhesive is a mixture of E51 epoxy resin and diluent XY-215 in a certain mass ratio; The curing agent is a mixture of modified polyetheramine UR6088 and polyetheramine D230 in a mass ratio of 4:5; The filler is glass powder, quartz powder, or nano-silica; The hydrophilic additive is Tween T20; The aggregate is 10-70 mesh snowflake white sand, chicken blood red sand, or washed river sand.

2. The method for preparing a sand-based microporous permeable surface material according to claim 1, characterized in that, After the mixture is loaded into the mold, the specimen is formed by layering and manual compaction to ensure the density of the aggregate. The mass error of the mixture in each mold does not exceed 5%. The specimen is cured at room temperature of 20±2℃ for 24 hours before demolding, and then placed in an oven at 70℃ for 24 hours.

3. The method for preparing a sand-based microporous permeable surface material according to claim 1, characterized in that, Slowly pour the modified polyetheramine UR6088 into the polyetheramine D230, stir and mix evenly, then place it in a vacuum drying oven, evacuate to below -0.095 MPa, and maintain for 5-10 minutes. The bubbles inside the curing agent will rapidly expand and rise to the surface and rupture, thus obtaining the curing agent.

4. The method for preparing a sand-based microporous permeable surface material according to claim 1, characterized in that, The amount of adhesive used is 5% of the aggregate mass.

5. The method for preparing a sand-based microporous permeable surface material according to claim 1, characterized in that, The hydrophilic additive is Tween T20, and the amount of the hydrophilic additive is 1.67% of the adhesive mass.

6. The method for preparing a sand-based microporous permeable surface material according to claim 1, characterized in that, The filler is glass powder, and the amount of glass powder used is 30%-40% of the adhesive mass.

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