Asphalt overlay structure and construction technology based on old cement pavement cracking and pressure stabilization layer

Abstract

The application relates to the technical field of highway reconstruction engineering, and particularly discloses an asphalt overlay structure based on a cracking and stabilizing layer of an old cement pavement and a construction process. The asphalt overlay structure based on the cracking and stabilizing layer of the old cement pavement comprises a surface layer arranged on the upper surface of the cracking and stabilizing layer, the surface layer is arranged by asphalt concrete, and the asphalt concrete comprises the following raw materials in parts by weight: coarse aggregate 50-70 parts, fine aggregate 20-30 parts, emulsified asphalt 10-15 parts, filler 10-15 parts, penetrating agent 2-3 parts, curing agent 1-2 parts and connecting agent 2-3 parts. The asphalt overlay structure based on the cracking and stabilizing layer of the old cement pavement has the advantages of reducing the occurrence of reflection cracks and reducing the damage of the reflection cracks to the asphalt concrete layer.

Description

Technical Field

[0001] This application relates to the field of highway reconstruction engineering, and more specifically, it relates to an asphalt overlay structure and construction technology based on a cracked and stabilized old cement pavement layer. Background Technology

[0002] Cement concrete pavement, as a major structural form of high-grade pavement, has advantages such as high strength, good stability, relatively long service life, and low initial maintenance costs. However, due to the surge in traffic volume, increasingly heavy vehicle axle loads, or design and construction issues, pavement damage such as exposed aggregate, cracking, broken slabs, subsidence, misalignment, breakage, and voids at the bottom of the slabs has occurred, affecting the road's usability.

[0003] The original cement concrete pavement slabs show obvious voids and loosening, with widespread transverse, longitudinal or diagonal cracks, mud pumping, misalignment and other defects, and obvious uneven settlement. The original roadbed density is insufficient; or the roadbed is relatively stable, with no large amount of water seepage, but only some slabs are severely broken and have settled.

[0004] Given the above road conditions, the most suitable treatment method is to first use a breaker to break up the original cement pavement into 10-15cm blocks and embed them into the road base. Then, manually spread graded gravel to fill the gaps, compact and level it, and finally lay an asphalt concrete layer.

[0005] The gaps between adjacent cement-aggregate aggregates are filled with graded sand and gravel. The surface layer is formed only by compaction. However, the cracks between the cement-aggregate aggregates can still be reflected in the asphalt concrete layer, causing the asphalt concrete layer to be damaged due to reflective cracking. Summary of the Invention

[0006] In order to reduce the occurrence of reflective cracks and reduce the damage of reflective cracks to asphalt concrete layers, this application provides an asphalt overlay structure and construction process based on the cracked and stabilized layer of old cement pavement.

[0007] In the first aspect, this application provides an asphalt overlay structure based on a cracked and stabilized old cement pavement layer, employing the following technical solution: An asphalt overlay structure based on a cracked and stabilized old cement pavement layer includes a surface layer laid on the upper surface of the cracked and stabilized layer. The surface layer is made of asphalt concrete, which comprises the following raw materials in parts by weight: 50-70 parts coarse aggregate, 20-30 parts fine aggregate, 10-15 parts emulsified filler, 10-15 parts asphalt, 2-3 parts penetrant, 1-2 parts curing agent, and 2-3 parts binder.

[0008] By adopting the above technical solution, since the penetrant and curing agent are introduced into the cracked and stabilized layer along with the emulsified asphalt, and the binder is mixed in the surface layer, when the penetrant and curing agent are cured, the penetrant and curing agent that have penetrated into the cracked and stabilized layer, as well as the emulsified asphalt, reinforce the cracked and stabilized layer, making the cracked and stabilized layer less prone to cracking. At the same time, the binder is connected to the cracked and stabilized layer through the cured penetrant and curing agent, thereby increasing the bonding strength between the surface layer and the cracked and stabilized layer, making the pavement structure more stable and less prone to damage.

[0009] Preferably, the penetrant is a mixture of polyvinyl alcohol and polyester polymer, wherein the weight ratio of polyvinyl alcohol to polyester polymer is 5:1.

[0010] By adopting the above technical solution, a mixture of polyvinyl alcohol and polyester polymers is used as a penetrant to penetrate into the crack-stabilized layer, eroding the cracks within the layer. This causes some loose powder to mix into the penetrant, resulting in the reappearance of cracks filled with loose powder. This facilitates the penetration of the curing agent into the cracks opened by the penetrant, thus strengthening the cracks together with the curing agent, the penetrant, and the emulsified asphalt.

[0011] Preferably, the penetrant is prepared by the following steps: mixing polyvinyl alcohol with deionized water by heating in a water bath, and then adding polyester polymer and stirring until uniform.

[0012] By adopting the above technical solution, polyvinyl alcohol and polyester polymers are added to concrete in the form of a solution, which facilitates the flow of polyvinyl alcohol and polyester polymers in the concrete and their penetration into the crack-stabilized layer after laying. The emulsified asphalt and curing agent in the asphalt structural layer then reach the crack-stabilized layer, and after filling the cracks, they are cured, thereby improving the overall structural strength of the crack-stabilized layer.

[0013] Preferably, the curing agent is a crystallizing agent and a butyl carboxystyrene rubber latex, wherein the weight ratio of the crystallizing agent and the butyl carboxystyrene rubber latex is 1:10.

[0014] By adopting the above technical solution, the crystallizer and carboxylated butyl styrene rubber emulsion are mixed, so that the curing agent can first penetrate into the crack-stabilized layer along with the penetrant. Then, both the crystallizer and carboxylated butyl styrene rubber will crystallize in the crack-stabilized layer, thereby improving the stability of the crack-stabilized layer and making it less prone to cracking again, thus effectively reducing the occurrence of reflective cracks.

[0015] Preferably, the curing agent is prepared by the following steps: adding a crystallizing agent to carboxylated styrene-butadiene latex and stirring to prepare the curing agent.

[0016] By adopting the above technical solution, carboxylated styrene-butadiene latex is used as the emulsion environment, which is more conducive to the uniform dispersion of the crystallizer and the penetration and crystallization of the curing agent. When the curing agent penetrates into the crack-stabilized layer along with the emulsified asphalt and penetrating agent, the uniform dispersion of the crystallizer makes the crystallization more uniform and the strengthening effect on the crack-stabilized layer is more prominent.

[0017] Preferably, the binder is a composite palygorskite-modified fiber.

[0018] By adopting the above technical solution, using composite palygorskite modified fiber as a binder inside concrete, when the penetrant and curing agent are cured, the roughness of the surface of the composite palygorskite modified fiber increases the bonding strength between the curing agent and penetrant and the concrete through the composite palygorskite modified fiber, thereby improving the bonding strength between the asphalt overlay and the cracked and stabilized layer.

[0019] Preferably, the composite palygorskite modified fiber is prepared by the following steps: surface-modified palygorskite, polyferric sulfate and sisal fiber are placed in deionized water, heated and stirred in a water bath, and then the sisal fiber is taken out and dried to obtain the composite palygorskite modified fiber.

[0020] By adopting the above technical solution, the surface roughness of sisal fiber is improved by using polyferric sulfate and palygorskite, thereby increasing the bonding strength between the curing agent and the binder during curing, and thus improving the bonding strength between the asphalt overlay and the cracked and stabilized layer.

[0021] Secondly, this application provides a construction process for an asphalt overlay structure based on a cracked and stabilized old cement pavement layer, employing the following technical solution: A construction process for an asphalt overlay structure based on a cracked and stabilized old cement pavement includes the following steps: mixing various raw materials to prepare asphalt concrete and then laying it on the cracked and stabilized layer to form a surface layer.

[0022] In summary, this application has the following beneficial effects: 1. Because penetrants and curing agents are introduced into the cracked and stabilized layer along with the emulsified asphalt, while the binder is mixed in the surface layer, when the penetrants and curing agents cure, the penetrants and curing agents that have penetrated into the cracked and stabilized layer, along with the emulsified asphalt, reinforce the cracked and stabilized layer, making it less prone to cracking. At the same time, the binder connects to the cracked and stabilized layer through the cured penetrants and curing agents, thereby increasing the bonding strength between the surface layer and the cracked and stabilized layer, making the pavement structure more stable and less prone to damage.

[0023] 2. In this application, sodium methylsilicate and butyl carboxystyrene rubber emulsion are mixed, so that the curing agent can first penetrate into the crack-stabilized layer along with the penetrant. Then, both sodium methylsilicate and butyl carboxystyrene rubber will crystallize in the crack-stabilized layer, thereby improving the stability of the crack-stabilized layer and making it less prone to cracking again, thus effectively reducing the occurrence of reflective cracks.

[0024] 3. In this application, composite palygorskite modified fiber is used as a binder inside the concrete. When the penetrant and curing agent are cured, the roughness of the surface of the composite palygorskite modified fiber increases the bonding strength between the curing agent and penetrant and the concrete through the composite palygorskite modified fiber, thereby improving the bonding strength between the asphalt overlay and the cracked and stabilized layer. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments.

[0026] Preparation Example Preparation Example 1 This preparation example discloses a penetrant, which is prepared by the following steps: S1. Polyvinyl alcohol is dissolved in deionized water under magnetic stirring in a 90°C hot water bath to obtain a 5wt% polyvinyl alcohol aqueous solution; S2. Polyethylene oxide is added to the polyvinyl alcohol aqueous solution in S1, with a weight ratio of 5:1 between polyethylene oxide and polyvinyl alcohol, and then glutaraldehyde solution is added dropwise, with a volume ratio of glutaraldehyde solution to polyvinyl alcohol aqueous solution in S1 of 1:20. Sulfuric acid is added to adjust the pH to 2, and the mixture is heated in a 90°C water bath for 30 minutes. Then, 1wt% sodium hydroxide solution is added dropwise to adjust the pH to neutral, which is then used as a penetrant.

[0027] Preparation Example 2 This preparation example discloses a penetrant, which is prepared by the following steps: S1. Polyvinyl alcohol is dissolved in deionized water under magnetic stirring in a 90°C hot water bath to obtain a 5wt% polyvinyl alcohol aqueous solution; S2. Sodium polyacrylate is added to the polyvinyl alcohol aqueous solution in S1, with a weight ratio of polycaprolactone to polyvinyl alcohol of 5:1. Then, glutaraldehyde solution is added dropwise, with a volume ratio of glutaraldehyde solution to polyvinyl alcohol aqueous solution in S1 of 1:20. Sulfuric acid is added to adjust the pH to 2. The mixture is heated in a 90°C water bath for 30 minutes, and then 1wt% sodium hydroxide solution is added dropwise to adjust the pH to neutral. This solution is then used as a penetrant.

[0028] Preparation Example 3 A curing agent is prepared by adding 0.5 kg of deionized water and 0.5 kg of potassium sodium tartrate to 5 kg of carboxylated styrene-butadiene latex and stirring.

[0029] Preparation Example 4 This preparation example discloses a curing agent, which is prepared by the following steps: A curing agent was prepared by adding 0.5 kg of deionized water and 0.5 kg of sodium methylsilicate to 5 kg of carboxylated styrene-butadiene latex and stirring.

[0030] Preparation Example 5 This preparation example discloses a binder, which is prepared by the following steps: S1. Cut the sisal fiber into 5mm short fiber segments, then dry the short fibers in a drying oven for 3 hours. The vacuum degree of the drying oven is -0.1Pa and the temperature is 80℃. Immerse the vacuum-dried sisal fiber in a 18% sodium hydroxide solution for 3 hours. Then wash it with distilled water until neutral. Finally, spread it out and air dry it for later use. S2. Wash palygorskite with water, grind it through a 200-mesh sieve, then stir and react it with 4 mol / L hydrochloric acid at a volume ratio of 5:1. Let it stand for one day, then add polyferric sulfate at a weight ratio of 1:2 to palygorskite and stir to mix evenly to obtain a suspension. Add the sisal fiber obtained in S1 to the suspension, immersing the sisal fiber in the suspension. Stir for 2 hours at a stirring speed of 200 r / min, wash with deionized water until neutral, and dry it to use as a binder.

[0031] Preparation Example 6 This preparation example discloses a binder, which is prepared by the following steps: Palaemonite was washed with water, crushed and ground through a 200-mesh sieve, and then reacted with 4 mol / L hydrochloric acid at a volume ratio of 5:1. The mixture was allowed to stand for one day. Polyferric sulfate was added at a weight ratio of 1:2 to palaemonite, and the mixture was stirred until homogeneous to obtain a suspension. Sisal fibers were submerged in the suspension. The mixture was stirred for 2 hours at a stirring speed of 200 r / min. The mixture was washed with deionized water until neutral and then dried to be used as a binder. Example

[0032] Example 1 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 500 kg of coarse aggregate and 200 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 100 kg of filler, heat and stir at 170°C for 10 seconds, then add 100 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 20 kg of penetrant prepared in Preparation Example 1, 10 kg of curing agent prepared in Preparation Example 3, and 20 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0033] Example 2 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Preparation Example 1, 15 kg of curing agent prepared in Preparation Example 3, and 25 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0034] Example 3 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 700 kg of coarse aggregate and 300 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 150 kg of filler, heat and stir at 170°C for 10 seconds, then add 150 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 30 kg of penetrant prepared in Preparation Example 1, 20 kg of curing agent prepared in Preparation Example 3, and 30 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0035] Example 4 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Preparation Example 2, 15 kg of curing agent prepared in Preparation Example 3, and 25 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0036] Example 5 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Preparation Example 1, 15 kg of curing agent prepared in Preparation Example 4, and 25 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0037] Example 6 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Preparation Example 1, 15 kg of curing agent prepared in Preparation Example 3, and 25 kg of binder prepared in Preparation Example 6, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0038] Example 7 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of 5 wt% polyvinyl alcohol aqueous solution, 15 kg of curing agent prepared in Preparation Example 3, and 25 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0039] Example 8 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Preparation Example 1, 15 kg of carboxylated styrene-butadiene latex and 25 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0040] Example 9 This embodiment discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Preparation Example 1, 15 kg of curing agent prepared in Preparation Example 3, and 25 kg of sisal fiber, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0041] Comparative Example Comparative Example 1 This comparative example discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Preparation Example 1 and 15 kg of curing agent prepared in Preparation Example 3, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0042] Comparative Example 2 This comparative example discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Preparation Example 1 and 25 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0043] Comparative Example 3 This comparative example discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 15 kg of curing agent prepared in Preparation Example 3 and 25 kg of binder prepared in Preparation Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0044] Comparative Example 4 This comparative example discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of penetrant prepared in Example 1, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0045] Comparative Example 5 This comparative example discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 15 kg of curing agent prepared in Example 3, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0046] Comparative Example 6 This comparative example discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and stir at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, then add 25 kg of the binder prepared in Example 5, mix at 165°C for 10 seconds, and maintain the discharge temperature at 165°C.

[0047] Comparative Example 7 This comparative example discloses an asphalt concrete, which is prepared by the following steps: Add 600 kg of coarse aggregate and 250 kg of fine aggregate, heat and mix at 180°C for 10 seconds, then add 125 kg of filler, heat and mix at 170°C for 10 seconds, then add 125 kg of emulsified asphalt, mix at 165°C for 5 seconds, and maintain the discharge temperature at 165°C.

[0048] Performance testing application example: First, a 5cm thick crack-stabilized layer is laid on the bottom 5cm cement concrete slab. Specifically, old cement concrete pavement gravel with a block size of 10cm is laid flat, then graded gravel is manually spread to fill the cracks and compacted. Finally, a 5cm thick asphalt concrete overlay is laid on the crack-stabilized layer.

[0049] For the asphalt concrete prepared in the embodiments and comparative examples, the application examples were set up in accordance with the above method, and multiple groups were set up to test various performance parameters.

[0050] Refer to the "Technical Specification for Construction of Asphalt Pavement on Highways" (JTG F40-2004) 1. T0719 Asphalt mixture rutting test: The specimen is a plate-shaped specimen with a length of 300mm, a width of 300mm, and a thickness of 150mm.

[0051] 2. T0709 Marshall stability test for asphalt mixtures.

[0052] Table 1 Performance Test Data Example 1 5240 92 Example 2 5320 95 Example 3 5270 93 Example 4 5030 87 Example 5 5070 86 Example 6 4970 86 Example 7 4990 84 Example 8 5040 87 Example 9 5080 83 Comparative Example 1 4130 76 Comparative Example 2 4050 72 Comparative Example 3 3980 69 Comparative Example 4 3920 65 Comparative Example 5 3810 63 Comparative Example 6 3790 61 Comparative Example 7 3710 59 As can be seen from Example 2 and Comparative Examples 1-7, and Table 1, since the penetrant and curing agent are introduced into the cracked and stabilized layer along with the emulsified asphalt, while the binder is mixed in the surface layer, when the penetrant and curing agent are cured, the penetrant and curing agent that have penetrated into the cracked and stabilized layer, as well as the emulsified asphalt, reinforce the cracked and stabilized layer, making it less prone to cracking. At the same time, the binder connects with the cracked and stabilized layer through the cured penetrant and curing agent, thereby increasing the bonding strength between the surface layer and the cracked and stabilized layer, making the pavement structure more stable and less prone to damage.

[0053] Based on Examples 2, 4, and 5 and Table 1, it can be seen that by mixing the crystallizer and carboxylated butyl styrene rubber emulsion, the curing agent can first penetrate into the crack-stabilized layer along with the penetrant. Then, both the crystallizer and carboxylated butyl styrene rubber will crystallize in the crack-stabilized layer, thereby improving the stability of the crack-stabilized layer and making it less prone to cracking again, thus effectively reducing the occurrence of reflective cracks.

[0054] Combining Examples 2, 6, and 7 with Table 1, it can be seen that using a mixture of polyvinyl alcohol and polyester polymers as a penetrant allows it to penetrate into the crack-stabilized layer, eroding the cracks within the layer. This causes some loose powder to mix into the penetrant, resulting in the reappearance of cracks previously filled with loose powder. This facilitates the penetration of the curing agent into the cracks opened by the penetrant, thus strengthening the cracks together with the curing agent, the penetrant, and the emulsified asphalt.

[0055] As can be seen from Examples 2, 8, and 9 and Table 1, when composite palygorskite modified fiber is used as a binder inside concrete, the roughness of the surface of the composite palygorskite modified fiber increases the bonding strength between the binder and the concrete through the composite palygorskite modified fiber when the penetrant and curing agent are cured, thereby improving the bonding strength between the asphalt overlay and the cracked and stabilized layer.

[0056] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An asphalt overlay structure based on a cracked and stabilized old cement pavement layer, characterized in that, The surface layer, laid on the surface of the cracked and stabilized layer, is composed of asphalt concrete. The asphalt concrete comprises the following raw materials in parts by weight: 50-70 parts coarse aggregate, 20-30 parts fine aggregate, 10-15 parts filler, 10-15 parts asphalt, 2-3 parts penetrant, 1-2 parts curing agent, and 2-3 parts binder. The penetrant is composed of polyvinyl alcohol and polyester polymers in a weight ratio of 5:

1. The penetrant is prepared by the following steps: mixing polyvinyl alcohol with deionized water under water bath heating... Then, polyester polymers are added and stirred until homogeneous; the curing agent is a crystallizing agent and carboxylated styrene-butadiene latex, and the weight ratio of the crystallizing agent and carboxylated styrene-butadiene latex is 1:10; the curing agent is prepared by the following steps: adding a crystallizing agent to carboxylated styrene-butadiene latex and stirring to prepare the curing agent; the binder is composite palygorskite modified fiber; the composite palygorskite modified fiber is prepared by the following steps: placing surface-modified palygorskite, polyferric sulfate and sisal fiber in deionized water, heating and stirring in a water bath, and then taking out the sisal fiber and drying it to obtain composite palygorskite modified fiber.

2. The construction process of the asphalt overlay structure based on the cracked and stabilized old cement pavement layer as described in claim 1, characterized in that: Includes the following steps: The asphalt concrete is prepared by mixing the raw materials and then laid on the cracked and stabilized layer to form the surface layer.