An asphalt pavement crack repairing method based on EICP technology

Abstract

The application provides a kind of asphalt pavement crack repair method based on EICP technology, it is related to road engineering field and biomimetic technology field.The repair method is repaired by using repair liquid, the repair liquid is obtained by mixing soybean urease solution and cementing liquid;The cementing liquid is urea, calcium compound and skimmed milk powder, and after adding water, stirring uniformly, wherein the optimum concentration ratio of soybean urease solution and cementing liquid is determined by orthogonal test;The repair method includes repair reaction space construction, repair reaction, maintenance polishing finishing and the like.The application is based on EICP technology, and the existing asphalt road crack repair method and the disadvantages of EICP technology in practical application are optimized, compared with other methods, has the advantages of fast, environmental protection, strong applicability, etc., and also provides a new method for asphalt pavement crack repair.

Description

Technical Field

[0001] This invention relates to the fields of road engineering and biomineralization technology, specifically to a method for repairing asphalt pavement cracks based on EICP technology. Background Technology

[0002] In recent years, my country's highway construction and development have achieved historic achievements. By the end of 2024, the total length of highways in China reached 5.4904 million kilometers, ranking first in the world. With the increase in highway mileage, my country has gradually entered a new stage of "equal emphasis on construction and maintenance." During their service life, roads are inevitably subjected to long-term effects from factors such as traffic loads, temperature, and humidity, leading to problems such as cracking. If not repaired in a timely manner, these cracks will further develop into more serious road defects, such as network cracks and potholes, which not only reduce driving comfort but also endanger road safety to some extent, seriously affecting the service performance and lifespan of the road surface. Therefore, timely and effective repair of road surface cracks not only plays a positive role in extending the service life of roads and improving road driving safety but also has good economic benefits.

[0003] Traditional methods for repairing road cracks, such as caulking and sealing, generally suffer from drawbacks such as being environmentally unfriendly, costly, and difficult to operate. Therefore, it is necessary to explore a new, more environmentally friendly, efficient, and widely applicable road crack repair technology. Biomineralization technology, with its readily available materials, green and low-carbon characteristics, environmental friendliness, strong adaptability, and low cost, has attracted attention from various fields and has been widely studied and applied in geology, water conservancy, and the environment. Microbial-induced calcium carbonate precipitation (MICP) and urease-induced calcium carbonate precipitation are two widely used biomineralization technologies. Their core principle is the same: urease promotes the hydrolysis of urea in the environment, which then reacts with calcium ions in the calcium source to form calcium carbonate crystals. The entire reaction process is shown in formulas (5) to (8). The difference between these two technologies lies in the different ways urease is produced: MICP technology mainly uses urease produced by microbial metabolism, while EICP (based on urease-induced calcium carbonate precipitation) technology directly prepares urease, eliminating the step of urease production by microbial metabolism, making the reaction process more controllable.

[0004] 5) 6) 7) 8) Although biomineralization technology has been applied relatively maturely in many fields, its application in crack repair, especially in road crack repair, still faces many problems and challenges: First, the reaction efficiency is not high. There are many factors affecting the EICP reaction, and it is difficult to comprehensively consider all of them. Existing studies often use a mixture of urease solution and cementing solution with fixed concentrations and ratios as the EICP remediation solution, ignoring the applicability of the component ratios of the remediation solution under different working conditions, thus resulting in low mineralization reaction efficiency.

[0005] Secondly, its application scope is relatively narrow. EICP reactions need to be carried out in a liquid environment. Currently, scholars' research on the application of this technology is still focused on the crack repair of materials with certain water retention properties, such as cement-based materials and masonry materials. Asphalt mixtures, which are commonly used in road construction, have poor water retention properties. Therefore, no research has yet applied this technology to the crack repair of asphalt pavements.

[0006] Third, the repair time is relatively long. Currently, the commonly used EICP method for repairing cracks involves pouring the EICP reaction solution into the crack, then periodically absorbing any remaining liquid and refilling with fresh solution. This method is time-consuming, often requiring 7 to 21 days or even longer depending on the crack's depth and width. This is not conducive to quickly reopening traffic. For example, the soaking, grouting, and injection methods used in patent CN118342618A all took at least 10 days to complete the repair of mortar cracks.

[0007] To address the aforementioned problems, this invention discloses a method for repairing asphalt pavement cracks based on EICP technology. This method, based on EICP technology, optimizes existing asphalt pavement crack repair methods and addresses the shortcomings of EICP technology in practical applications, providing a new approach for pavement crack repair. Compared to traditional crack repair methods and existing EICP-based crack repair methods, this method offers advantages such as speed, environmental friendliness, and broad applicability: Regarding reaction efficiency, orthogonal experiments are conducted using five easily controllable factors influencing the EICP reaction to obtain the optimal ratio of the repair fluid suitable for current temperature, humidity, and other working conditions, thus improving the efficiency of the mineralization reaction; regarding repair speed, crack repair can be completed in one reaction cycle, representing a significant improvement in repair speed compared to commonly used EICP-based crack repair methods; and regarding environmental friendliness, the repair fluid and byproducts of this method are abundant in nature, making it more environmentally friendly than traditional asphalt pavement crack repair methods. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a method for repairing asphalt pavement cracks based on EICP technology, which features rapid, environmentally friendly, and highly applicable repair of asphalt pavement cracks.

[0009] To achieve the above objectives, the present invention provides the following technical solution: A method for repairing asphalt pavement cracks based on EICP technology, wherein the repair method involves using a repair fluid, which is obtained by mixing soybean urease solution and cementing liquid; the cementing liquid is made by mixing urea, calcium compound and skim milk powder with water and stirring evenly, wherein the optimal concentration ratio of soybean urease solution and cementing liquid is determined by experiment.

[0010] Preferably, the method for preparing the soybean urease solution includes the following steps: S11. Place the soybeans in an oven and dry them at 80℃ for 3 hours; S12. Place the dried soybeans into a grinder and grind them in batches and multiple times. Then pass the ground soybean powder through a 50-mesh sieve. S13. Using ammonium sulfate as a salting-out agent, weigh the appropriate mass of soybean powder and salting-out agent according to the ratio of ammonium sulfate to soybean powder 1:10 and put them into a beaker. Add water to make up the volume to prepare a soybean powder-ammonium sulfate mixed solution. Then put the mixed solution into an electromagnetic stirrer and stir at a speed of 2000 r / min for 30 min to make the soybean powder and ammonium sulfate evenly distributed in the solution. S14. Pour the soybean flour-ammonium sulfate mixed solution in the beaker into a centrifuge tube, place it in a centrifuge and centrifuge at 4000 r / min for 30 min. The supernatant obtained by sieving the centrifuged liquid is the soybean urease solution.

[0011] Preferably, the method for determining the optimal concentration ratio of the soybean urease solution and the cementing solution includes the following steps: S21. Select the key factors affecting the EICP remediation reaction, and set the corresponding factor levels according to reagent type, solubility, etc., in order to study the influence of each factor on the experimental results. S22. Mix soybean urease solution and cementing solution at a volume ratio of 1:1 to obtain repair solution, and record the volume of repair solution as V. S23. Record the calcium ion concentration in the cementing solution before the reaction as C1. After the reaction is completed, use the EDTA method to determine the calcium ion concentration in the repair solution and record it as C2. S24. Calculate the mass m of calcium carbonate produced in the reaction using formula (1): (1); S25. Following the factors selected and the set factor levels in step S21, repeat experimental steps S22-S24 until all experiments are completed. Use the generated calcium carbonate mass m as the evaluation index for analysis to determine the optimal concentration ratio of each component of the repair solution under the current operating conditions. The calcium compound is at least one of calcium chloride, calcium acetate, calcium formate, calcium lignosulfonate, and calcium nitrate.

[0012] Preferably, the repair method specifically includes the following steps: S31. The crack to be repaired is cleaned, water retention effect tested, waterproofed, and dimensional measured in sequence. Then, relevant parameters are calculated, and the reaction space is expanded according to the calculation results to complete the construction of the repair reaction space. S32. Pour the prepared repair solution into the repair reaction space, making the surface of the repair solution flush with the top of the constructed reaction space, and wait for the repair reaction to complete. S33. Remove the liquid from the reaction space and dismantle the additional reaction space expanded in step S31. Allow the crack to dry completely before grinding the surface of the crack to make the asphalt pavement crack repair area smooth.

[0013] Preferably, the specific method for constructing the repair reaction space in step S31 includes the following steps: S41. Clean the dust, debris, and loose wall material inside and around the cracks in the road surface to be repaired; S42. Pour liquid into the crack until the liquid level is flush with the top surface of the crack. Insert a paper stick into the crack until it touches the bottom, and measure the length of the water-soaked stick. Record this length as _____. a After waiting for 1 hour, measure the length of the wetted area using the same method and record it as... b ; S43. Calculate the water seepage rate of the crack to be repaired over 1 hour according to formula (2). S ,like S >2, waterproof coating must be applied to the inner wall and surrounding area of ​​the crack for waterproofing treatment, and the water retention capacity of the crack after waterproofing treatment should be tested; if S If the value is less than 2, no additional treatment is required for the cracks; (2) S44. Measure the total length of the crack edge and record it as... L ; S45. Pour the repair solution into a flat-bottomed test tube, measure the height of the liquid in the test tube, and record it as _____. c After waiting 24 hours for the repair solution to react, measure the height of the generated crystals from the bottom of the test tube, and record it as _____. d The repair coefficient is calculated according to formula (3). n ; (3) S46. Calculate the height of the additional reaction space required according to formula (4). H : (4) S47. Using a waterproof flexible board with a certain degree of plasticity, cut the following side lengths: ( L +10)mm, ( HA rectangular waterproof flexible sheet with a diameter of +10 mm was used. The waterproof template was glued and fixed along the edge of the crack, and the waterproof flexible sheet was glued along the overlapping area. Then, its water retention was tested to ensure that a water-retaining space was formed to expand the space for repair reaction.

[0014] Preferably, the curing time in step S33 is 24~48 hours, which may be increased or decreased depending on the specific environmental conditions.

[0015] Preferably, the waterproof coating used in step S42 includes, but is not limited to, emulsified asphalt, waterproof adhesive, polyurethane waterproof coating, and other coatings with waterproof functions.

[0016] Preferably, in step S46, the waterproof flexible board material used includes, but is not limited to, PP sheet, PET sheet, and coated paperboard, and the adhesive material used includes, but is not limited to, hot melt adhesive and glass.

[0017] This invention provides a method for repairing asphalt pavement cracks based on EICP technology, which has the following advantages compared with existing technologies: (1) This invention takes into account the key influencing factors that are easy to control during the EICP reaction process, and can obtain the repair solution combination with the highest mineralization reaction efficiency under the current working conditions. Compared with the repair solution with a single ratio, the repair solution combination obtained by experimental analysis has a higher repair reaction efficiency under the current repair working conditions. (2) This invention introduces EICP technology into the repair of cracks in asphalt roads. Compared with traditional methods for repairing cracks in asphalt roads, this method is more environmentally friendly and expands the application scope of EICP technology to a certain extent. (3) The present invention adopts the method of expanding the reaction space. Compared with other applications of EICP in crack repair, this method has a significant improvement in repair speed. The crack repair can be completed in just one reaction cycle. Attached Figure Description

[0018] Figure 1 This is a flowchart of the asphalt pavement crack repair method proposed in this invention; Figure 2 This is a flowchart of the soybean urease extraction method used in this invention; Figure 3 A schematic diagram of the reaction space constructed according to the present invention; Figure 4 This is a diagram showing the repair completed according to Embodiment 1 of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: The pavement crack repair method based on EICP technology simulates actual road cracks by preparing Marshall specimens with pre-fabricated cracks in the laboratory and then repairing the cracks using the implementation method of this application. The flowchart is shown below. Figure 1 As shown, the specific steps include: S1. Taking the extraction of soybean urease solution from a soybean flour solution with a concentration of 100 g / L as an example, the soybean urease solution extraction is performed. The flowchart of the soybean urease extraction method is as follows: Figure 2 As shown, the specific steps include: S11. Weigh 100g of commercially available soybeans using an electronic balance, and then place them in an oven to dry at 80℃ for 3 hours. S12. Put the dried soybeans from step S11 into a grinder and grind them in batches and multiple times. Then, pass the ground soybean powder through a 50-mesh sieve. S13. Weigh 20g of the soybean powder obtained in step S12 into a beaker. Using ammonium sulfate as a salting-out agent, weigh 2g of ammonium sulfate crystals according to the ratio of ammonium sulfate to soybean powder of 1:10 and add them to the beaker containing 20g of soybean powder. Add water to make up to 200mL to prepare a soybean powder-ammonium sulfate mixed solution of the corresponding concentration. Then, put the mixed solution into an electromagnetic stirrer and stir at a speed of 2000r / min for 30min to make the soybean powder and ammonium sulfate evenly distributed in the solution. S14. Pour the soybean flour-ammonium sulfate mixed solution prepared in step S13 into centrifuge tubes, place them in a centrifuge and centrifuge at 4000 r / min for 30 min. The supernatant obtained by sieving the centrifuged liquid is the soybean urease solution extracted from the soybean flour solution with a concentration of 75 g / L after purification using this optimized method. S2. Taking the preparation of a cementing solution containing 1 mol / L urea, 1 mol / L calcium chloride, and 6 g / L skim milk powder as an example, the preparation method of the cementing solution is described. Specific steps include: weighing 11.01 g of anhydrous calcium chloride crystals, 6.06 g of urea crystals, and 0.6 g of skim milk powder, placing them in a beaker, and adjusting the volume to 100 mL with deionized water. Stir thoroughly for 30 min using a magnetic stirrer to prepare a cementing solution with a concentration of 1 mol / L calcium chloride solution, 1 mol / L urea solution, and 6 g / L skim milk powder. Then, mix the soybean urease solution and the cementing solution at a volume ratio of 1:1 to obtain the repair solution. Appropriate indicators should be selected as evaluation indicators as needed. The optimal concentration ratio of soybean urease to the cementing solution is determined by single-factor experiments, using the calcium carbonate formation rate as an example. m The evaluation index is calculated using formula (1): (1) To determine the optimal concentration ratio of each component of the repair solution under current operating conditions, the specific steps include: S21. Prepare soybean flour solutions with concentrations of 20 g / L, 40 g / L, 60 g / L, 80 g / L, and 100 g / L respectively, and extract the corresponding urease solutions. The cementing solution is calcium chloride with a concentration of 1 mol / L, urea to calcium ion concentration ratio of 1, and reaction time is 8 h. The calcium ion concentration after 8 h of reaction is determined by EDTA method, and the mass of calcium carbonate generated is calculated according to formula (1). The results are shown in Table 1. As can be seen from Table 1, when the soybean flour concentration is 100 g / L, the calcium carbonate generation is the highest, and the solubility of the soybean flour solution prepared at this concentration is close to saturation. Therefore, a soybean flour solution with a concentration of 100 g / L is selected for urease solution extraction and used for subsequent experiments. Table 1. Calcium carbonate formation at different soybean flour concentrations S22. With the calcium ion concentration fixed at 1 mol / L and the urea to calcium ion concentration ratio unchanged at 1, calcium chloride, calcium formate, and calcium acetate were selected as calcium sources for cementing solution preparation, and the reaction time was 8 h. The calcium ion concentration after 8 h of reaction was determined by EDTA method, and the mass of calcium carbonate generated was calculated according to formula (1). The results are shown in Table 2. As can be seen from Table 2, the calcium carbonate generated by EICP reaction is the highest when calcium chloride is used as the calcium source. Therefore, calcium chloride was selected as the calcium source for cementing solution preparation. Table 2. Calcium carbonate formation under different calcium sources S23. With calcium chloride as the fixed calcium source and the urea-to-calcium ion concentration ratio remaining constant at 1, cementing solutions with calcium chloride concentrations of 0.3 mol / L, 0.6 mol / L, and 1 mol / L were prepared, and the reaction time was 8 h. The calcium ion concentration after 8 h of reaction was determined using the EDTA method, and the mass of calcium carbonate produced was calculated according to formula (1). The results are shown in Table 3. As can be seen from Table 3, the calcium carbonate production in the EICP reaction is highest when the calcium ion concentration is 1 mol / L. Therefore, a calcium chloride concentration of 1 mol / L was selected for preparing the cementing solution. Table 3. Calcium carbonate formation at different calcium chloride concentrations S24. A cementing solution was prepared with a fixed calcium chloride concentration of 1 mol / L and a urea to calcium ion concentration ratio of 1. The reaction times were 8 h, 16 h, and 24 h. The calcium ion concentration after 8 h, 16 h, and 24 h of reaction was determined by EDTA method. The mass of calcium carbonate generated was calculated according to formula (1). The results are shown in Table 4. As can be seen from Table 4, the amount of calcium carbonate generated gradually increases with the increase of reaction time, but the amount of calcium carbonate generated per unit hour shows a decreasing trend. Therefore, 8 h was selected as the remediation reaction time. Table 4. Calcium carbonate production at different reaction times S25. With the calcium chloride concentration fixed at 1 mol / L and the urea to calcium ion concentration ratio unchanged at 1, gelling solutions containing 2 g / L, 4 g / L, and 6 g / L skim milk powder were prepared respectively, and the reaction time was 8 h. The calcium ion concentration after the reaction was completed was determined by EDTA method, and the mass of calcium carbonate generated was calculated according to formula (1). The results are shown in Table 5. As can be seen from Table 5, the mass of calcium carbonate generated by the repair solution is the highest when the skim milk powder concentration is 4 g / L. Therefore, 4 g / L is selected as the optimal concentration of skim milk powder in the repair solution. Table 5. Calcium carbonate formation at different skim milk powder concentrations S26. Based on the above experimental results, the optimal concentration ratio of each component of the repair solution under the current working conditions was determined by mixing the soybean urease solution extracted from soybean flour solution with a concentration of 100 g / L with a cementing solution containing calcium chloride concentration of 1 mol / L, urea concentration of 1 mol / L, and skim milk powder concentration of 4 g / L at a volume ratio of 1:1, and the repair reaction time was determined to be 8 h. S3. Following the asphalt mixture specimen preparation method (compaction method) described in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410—2025), Marshall specimens with a height of 101.6 mm and a diameter of 63.5 mm were formed in the laboratory. Before compacting the asphalt mixture using a compactor, a stainless steel plate with a length, width, and height of 80 mm, 3 mm, and 20 mm respectively was inserted into the center of the mixture to prepare a Marshall specimen with pre-existing cracks. S4. Clean the crack to be repaired, test its water retention effect, perform waterproofing treatment, measure the crack size, calculate parameters, and expand the reaction space. Finally, complete the construction of the repair reaction space. The schematic diagram of the constructed reaction space is shown below. Figure 3 As shown, the specific steps include: S41. Use tools such as air blowers and brushes to clean the dust, debris and loose wall material inside and around the crack to be repaired. S42. Pour water into the crack until the surface of the liquid is flush with the road surface. Insert a paper stick of appropriate length into the crack until it touches the bottom, and measure the length of the water-soaked stick. Record this length as [the length of the water-soaked stick]. a ,result a= 20.1mm; after waiting 1 hour, the wetted length was measured using the same method and recorded as . b , b =17.3mm; Calculate the water seepage rate of the crack to be repaired over 1 hour according to formula (2). S =13.93. Because S >2. Polyurethane waterproof coating was used to waterproof the inner wall and surrounding area of ​​the crack. The water retention performance of the crack was then retested. The water retention performance of the crack was good after the waterproofing treatment. (2) S43. The total length of the crack edge was measured and found to be 168 mm. S44. Prepare the repair solution according to the optimal concentration ratio of each component obtained in step S2. Pour an appropriate amount of the repair solution into a flat-bottomed test tube and measure the height of the liquid from the bottom of the test tube, recording it as _____. c , c =55mm; After waiting 24 hours for the repair solution to react, measure the height of the generated crystals from the bottom of the test tube and record it as . d , d =7mm; the repair coefficient is calculated according to formula (3). n =7.86; (3) S45. According to formula (4), the height of the additional reaction space that needs to be constructed is 158 mm. (4) S46. Use a waterproof flexible sheet with a certain degree of plasticity, cut it into a rectangular waterproof flexible sheet with a size of 178mm×168mm, use hot melt adhesive to stick and fix the waterproof template along the edge of the crack and stick the waterproof flexible sheet along the overlapping part, and then test its water retention to ensure that a water-retaining space is formed to expand the repair reaction space. S5. Pour the repair solution prepared according to the optimal concentration ratio into the repair reaction space, making the surface of the repair solution flush with the top of the constructed reaction space, and wait for the repair reaction to proceed for 8 hours. S6. Remove the liquid from the reaction space and dismantle the additionally expanded reaction space from step S4. After 24 hours of curing, observe that the crystals filling the cracks have completely dried. Then, polish the surface of the cracks to make the repaired area smooth. The repaired specimen is as follows: Figure 4 As shown.

[0021] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for repairing asphalt pavement cracks based on EICP technology, characterized in that: The repair method involves using a repair solution, which is obtained by mixing soybean urease solution and a cementing solution. The cementing solution is made by mixing urea, calcium compound, and skim milk powder with water and stirring until homogeneous. The optimal concentration ratio of soybean urease solution to cementing solution is determined experimentally.

2. The repair method according to claim 1, characterized in that, The method for preparing the soybean urease solution includes the following steps: S11. Place the soybeans in an oven and dry them at 80℃ for 3 hours; S12. Place the dried soybeans into a grinder and grind them in batches and multiple times. Then pass the ground soybean powder through a 50-mesh sieve. S13. Using ammonium sulfate as a salting-out agent, weigh the appropriate mass of soybean powder and salting-out agent according to the ratio of ammonium sulfate to soybean powder 1:10 and put them into a beaker. Add water to make up the volume to prepare a soybean powder-ammonium sulfate mixed solution. Then put the mixed solution into an electromagnetic stirrer and stir at a speed of 2000 r / min for 30 min to make the soybean powder and ammonium sulfate evenly distributed in the solution. S14. Pour the soybean flour-ammonium sulfate mixed solution in the beaker into a centrifuge tube, place it in a centrifuge and centrifuge at 4000 r / min for 30 min. The supernatant obtained by sieving the centrifuged liquid is the soybean urease solution.

3. The repair method according to claim 1, characterized in that, The method for determining the optimal concentration ratio of the soybean urease solution and the cementing solution includes the following steps: S21. Select the key factors affecting the EICP remediation reaction, and set the corresponding factor levels according to reagent type, solubility, etc., in order to study the influence of each factor on the experimental results. S22. Mix soybean urease solution and cementing solution at a volume ratio of 1:1 to obtain repair solution, and record the volume of repair solution as V. S23. Record the calcium ion concentration in the cementing solution before the reaction as C1. After the reaction is completed, use the EDTA method to determine the calcium ion concentration in the repair solution and record it as C2. S24. Calculate the mass m of calcium carbonate produced in the reaction using formula (1): (1)； S25. Following the factors selected and the factor levels set in step S21, repeat experimental steps S22 to S24 until all experiments are completed. Use the mass m of the generated calcium carbonate as the evaluation index for analysis to determine the optimal concentration ratio of each component of the repair solution under the current working conditions.

4. The repair method according to claim 1, characterized in that: The calcium compound is at least one of calcium chloride, calcium acetate, calcium formate, calcium lignosulfonate, and calcium nitrate.

5. The repair method according to claim 1, characterized in that, The repair method specifically includes the following steps: S31. The crack to be repaired is cleaned, water retention effect tested, waterproofed, and dimensional measured in sequence. Then, relevant parameters are calculated, and the reaction space is expanded according to the calculation results to complete the construction of the repair reaction space. S32. Pour the prepared repair solution into the repair reaction space, making the surface of the repair solution flush with the top of the constructed reaction space, and wait for the repair reaction to complete. S33. Remove the liquid from the reaction space and dismantle the additional reaction space expanded in step S31. Allow the crack to dry completely before grinding the surface of the crack to make the asphalt pavement crack repair area smooth.

6. The repair method according to claim 5, characterized in that, The specific method for constructing the repair reaction space in step S31 includes the following steps: S41. Clean the dust, debris, and loose wall material inside and around the cracks in the road surface to be repaired; S42. Pour liquid into the crack until the liquid level is flush with the top surface of the crack. Insert a paper stick into the crack until it touches the bottom, and measure the length of the water-soaked stick. Record this length as _____. a After waiting for 1 hour, measure the length of the wetted area using the same method and record it as... b ; S43. Calculate the water seepage rate of the crack to be repaired over 1 hour according to formula (2). S ,like S >2, waterproof coating must be applied to the inner wall and surrounding area of ​​the crack for waterproofing treatment, and the water retention capacity of the crack after waterproofing treatment should be tested; if S If the value is less than 2, no additional treatment is required for the cracks; (2) S44. Measure the total length of the crack edge and record it as... L ; S45. Pour the repair solution into a flat-bottomed test tube, measure the height of the liquid in the test tube, and record it as _____. c After waiting 24 hours for the repair solution to react, measure the height of the generated crystals from the bottom of the test tube, and record it as _____. d The repair coefficient is calculated according to formula (3). n ; (3) S46. Calculate the height of the additional reaction space required according to formula (4). H : (4) S47. Using a waterproof flexible board with a certain degree of plasticity, cut the following side lengths: ( L +10)mm, ( H A rectangular waterproof flexible sheet with a diameter of +10 mm was used. The waterproof template was glued and fixed along the edge of the crack, and the waterproof flexible sheet was glued along the overlapping area. Then, its water retention was tested to ensure that a water-retaining space was formed to expand the space for repair reaction.

7. The repair method according to claim 5, characterized in that: The curing time in step S33 is 24~48 hours, which may be increased or decreased depending on the specific environmental conditions.

8. The repair method according to claim 6, characterized in that: The waterproof coatings used in step S42 include, but are not limited to, emulsified asphalt, waterproof adhesives, polyurethane waterproof coatings, and other coatings with waterproof functions.

9. The repair method according to claim 6, characterized in that: In step S46, the waterproof flexible board materials used include, but are not limited to, PP sheet, PET sheet, and coated paperboard, and the adhesive materials used include, but are not limited to, hot melt adhesive and glass.

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