Recycled aggregate asphalt concrete as well as preparation method and application thereof

Abstract

The invention discloses recycled aggregate asphalt concrete as well as a preparation method and application thereof, and belongs to the technical field of asphalt concrete. 70 to 90 parts of regenerated aggregate; 5-10 parts of an initiator; 25 to 35 parts of quartz sand; 5 to 15 parts of cement; 8 to 12 parts of water; wherein the recycled aggregate is prepared from waste concrete blocks, acrylamide and a cross-linking agent. The preparation method comprises the following steps: S1, dissolving acrylamide and a cross-linking agent to obtain a mixed solution; waste concrete blocks are soaked in the mixed solution and dried, and regenerated aggregate is obtained; s2, an initiator and water are mixed to prepare an initiator solution, the initiator solution, the recycled aggregate, quartz sand and cement are mixed to obtain a mixture, asphalt is heated and then stirred with the mixture, and the recycled aggregate asphalt concrete is obtained. The concrete provided by the invention has good integrity and stability, and also realizes replacement of natural coarse aggregate by waste concrete blocks.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt concrete, and in particular to a recycled aggregate asphalt concrete, a preparation method thereof, and an application thereof. Background Art

[0002] As a widely used pavement material, asphalt concrete is mainly made by mixing materials such as asphalt, cement, sand and gravel. Its main function is to provide sufficient bearing capacity for the road surface to support the weight of vehicles and other heavy objects, thereby extending the service life of the road surface. However, with the acceleration of the urbanization process, due to reasons such as urban planning adjustment, expansion and reconstruction, a large number of concrete structures have been demolished, generating a large amount of construction waste such as waste concrete. If these waste concretes cannot be effectively utilized, they will not only occupy a large amount of land resources, but also have a negative impact on the environment.

[0003] Existing methods use waste concrete as recycled aggregate to replace or partially replace aggregates such as sand and gravel in asphalt concrete. This approach can not only reduce the production cost of asphalt concrete, but also realize the recycling of waste concrete, with significant economic and environmental benefits. However, during the demolition and crushing of waste concrete, a large number of cracks will be generated on its surface and inside. When these waste concretes are added to asphalt concrete as recycled aggregate, these cracks will affect the stability of asphalt concrete and reduce its performance.

[0004] Therefore, it is necessary to develop a recycled aggregate asphalt concrete with good integrity and stability. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, in the first aspect, the present invention provides a recycled aggregate asphalt concrete, which has good integrity and stability and improves the utilization rate of waste concrete.

[0006] In the second aspect, the present invention also provides a preparation method of the recycled aggregate asphalt concrete.

[0007] In the third aspect, the present invention also provides a construction method of the recycled aggregate asphalt concrete.

[0008] The recycled aggregate asphalt concrete provided by the embodiment of the first aspect of the present invention includes the following components calculated by weight:

[0009] 35 - 45 parts of asphalt;

[0010] 70 - 90 parts of recycled aggregate;

[0011] 5 - 10 parts of initiator;

[0012] 25 - 35 parts of quartz sand;

[0013] 5 - 15 parts of cement;

[0014] 8 - 12 parts of water;

[0015] Wherein, the recycled aggregate is made of waste concrete blocks, acrylamide and a crosslinking agent.

[0016] The recycled aggregate asphalt concrete according to the embodiment of the present invention has at least the following beneficial effects:

[0017] In the present invention, the waste concrete blocks, acrylamide and the crosslinking agent are made into recycled aggregate. The acrylamide and the crosslinking agent form a protective layer on the surface of the waste concrete blocks and penetrate into the microcracks. When the recycled aggregate is mixed with other components, the acrylamide and the crosslinking agent in the microcracks react with water and an initiator to undergo polymerization and crosslinking reactions, adhesively bonding the inner walls on both sides of the microcracks inside the microcracks, thereby repairing the waste concrete blocks. The acrylamide and the crosslinking agent on the surface penetrate and polymerize and crosslink with other components when encountering water and an initiator, forming a three-dimensional network structure in the asphalt concrete, forming a transition at the interface between the surface of the waste concrete blocks and the asphalt, and the heat generated by the polymerization crosslinking and cement hydration is beneficial to improving the local fluidity at the interface between the asphalt and the surface of the waste concrete blocks so as to fill the gaps. Under the combined action, on the one hand, the microcracks of the waste concrete blocks are repaired and strengthened, and on the other hand, the integrity of the recycled aggregate asphalt concrete is improved, and the stability of the recycled aggregate asphalt concrete is improved; the dynamic stability of the recycled aggregate asphalt concrete of the present invention reaches 3120 times / mm, and the immersion residual stability is 93.1%.

[0018] This application uses waste concrete to make recycled aggregate, utilizes the waste concrete and completely replaces coarse aggregates such as natural stones, reducing the raw material cost; the present invention reuses the waste concrete, realizes the recycling of resources, reduces the generation of construction waste, and has remarkable environmental benefits.

[0019] According to some embodiments of the present invention, the crosslinking agent includes at least one of N, N'-methylenebisacrylamide, trimethylolpropane triacrylate and ethylene glycol dimethacrylate.

[0020] Preferably, the crosslinking agent is N, N'-methylenebisacrylamide.

[0021] According to some embodiments of the present invention, the mass ratio of the acrylamide to the crosslinking agent is 1:0.003 - 0.005.

[0022] According to some embodiments of the present invention, in the recycled aggregate, the mass percentage of the acrylamide and the crosslinking agent in the waste concrete blocks is 8% - 55%.

[0023] Preferably, in the recycled aggregate, the acrylamide and the crosslinking agent account for 12%-38% of the mass of the waste concrete block.

[0024] According to some embodiments of the present invention, the recycled aggregate comprises the following components calculated by weight:

[0025] 15-25 parts of waste concrete block;

[0026] 2-8 parts of acrylamide;

[0027] 0.01-0.03 parts of crosslinking agent.

[0028] According to some embodiments of the present invention, the initiator comprises at least one of ammonium persulfate, potassium persulfate and sodium persulfate.

[0029] Preferably, the initiator is ammonium persulfate.

[0030] According to some embodiments of the present invention, the asphalt is SBS modified asphalt.

[0031] According to some embodiments of the present invention, the dosage of the initiator is 5%-10% of the mass of the recycled aggregate.

[0032] According to some embodiments of the present invention, the cement is ordinary Portland cement of 42.5 grade.

[0033] According to the preparation method of the recycled aggregate asphalt concrete provided by the second aspect embodiments of the present invention, the method comprises the following steps:

[0034] S1. Dissolve acrylamide and the crosslinking agent to obtain a mixed solution; soak the waste concrete block in the mixed solution, and obtain the recycled aggregate after drying;

[0035] S2. Mix the initiator and water to make an initiator solution, mix the initiator solution, the recycled aggregate, quartz sand and cement to obtain a mixture, heat the asphalt and stir it together with the mixture to obtain the recycled aggregate asphalt concrete.

[0036] According to the preparation method of the embodiments of the present invention, it has at least the following beneficial effects:

[0037] In the present invention, waste concrete blocks are immersed in a mixed solution of acrylamide and a crosslinking agent. The acrylamide and the crosslinking agent can penetrate into the microcracks of the waste concrete blocks to form a protective layer and perform repairs. This not only improves the strength of the recycled aggregate but also reduces the influence of microcracks on the performance of the recycled aggregate. By mixing an initiator and water to form an initiator solution and then mixing it with the recycled aggregate, quartz sand, and cement, the polymerization reaction of acrylamide and the crosslinking agent can be promoted to form a three-dimensional network structure. This structure forms a transition layer at the interface between the surface of the recycled aggregate and the asphalt, enhancing the integrity of the recycled aggregate asphalt concrete.

[0038] During the stirring process, acrylamide and the crosslinking agent undergo polymerization and crosslinking reactions when encountering water and the initiator, further enhancing the stability of the recycled aggregate. This polymerization reaction not only improves the strength of the recycled aggregate but also increases the dynamic stability and immersion residual stability of the recycled aggregate asphalt concrete.

[0039] The preparation method of the present invention is simple and easy to implement, with convenient operation and easy industrial production. Through clear steps and conditions, the quality and performance of the recycled aggregate asphalt concrete are ensured.

[0040] According to some embodiments of the present invention, in step S1, the particle size of the waste concrete blocks is 20 - 25 mm.

[0041] According to some embodiments of the present invention, in step S1, the soaking duration is 8 - 12 h.

[0042] According to some embodiments of the present invention, in step S2, the temperature of the heated asphalt is 155 - 180 °C.

[0043] According to some embodiments of the present invention, in step S2, the stirring speed is 800 - 1200 r / min.

[0044] According to some embodiments of the present invention, in step S2, the stirring time is 20 - 40 min.

[0045] According to some embodiments of the present invention, in step S2, the stirring temperature is 125 - 135 °C.

[0046] According to some embodiments of the present invention, in step S2, after stirring, a cooling treatment is further included, cooling to 70 - 80 °C.

[0047] The third aspect of the present invention provides a construction method for the above-mentioned recycled aggregate asphalt concrete, including:

[0048] Performing the first paving on the recycled aggregate asphalt concrete, then rolling it flat, then performing the second paving, and then rolling it flat until the compaction degree meets the standard.

[0049] The construction method according to the embodiments of the present invention has at least the following beneficial effects:

[0050] The construction method of the present invention complies with the standards of the "Technical Specification for Construction of Highway Asphalt Pavements" JTJ 032-94, ensuring the construction quality and project safety. Through strict construction techniques and quality control, the reliability and durability of recycled aggregate asphalt concrete in practical applications are ensured.

[0051] The fourth aspect of the present invention provides the application of the above-mentioned recycled aggregate asphalt concrete in an asphalt concrete structure.

[0052] Other features and advantages of the present invention will be described in the subsequent specification, and, in part, will become apparent from the specification, or will be understood by implementing the present invention. Detailed Embodiments

[0053] The embodiments of the present invention will be described in detail below. The same or similar reference numerals throughout the embodiments denote the same or similar elements or elements having the same or similar functions. The embodiments described below are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0054] In the description of the present invention, if the first, second, etc. are described only for the purpose of distinguishing technical features, they should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0055] The terms "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain cases. However, in the same case or other cases, other embodiments may also be preferred. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not available, nor is it intended to exclude other embodiments from the scope of the present invention.

[0056] When a numerical range is disclosed herein, the above range is considered continuous and includes the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when the range refers to an integer, it includes each integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0057] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of the present invention.

[0058] The reagents, methods, and equipment used in the present invention are all conventional reagents, methods, and equipment in this technical field unless otherwise specified.

[0059] The cement is commercially available 42.5 ordinary Portland cement;

[0060] Ammonium persulfate, CAS No.: 7727-54-0.

[0061] N, N'-Methylenebisacrylamide, CAS No.: 110-26-9.

[0062] Quartz sand, No. 4 quartz sand, particle size 1.18 - 2.36 mm.

[0063] Asphalt: Dejia No. 70 SBS modified asphalt;

[0064] The waste concrete blocks of the present invention are obtained by crushing and screening the concrete from bridge demolition and then cleaning the surface dust and mortar. The crushing value is 20.8, the soundness is 9.1, the soft stone content is 1.1, and the Los Angeles abrasion loss is 22.6%.

[0065] Example 1

[0066] This embodiment provides a recycled aggregate asphalt concrete, and its components include: SBS modified asphalt, initiator ammonium persulfate, quartz sand, cement, water, recycled aggregate;

[0067] Among them, the recycled aggregate is made of waste concrete blocks, acrylamide, and crosslinking agent N, N'-methylenebisacrylamide.

[0068] This embodiment also provides a preparation method for the above-mentioned recycled aggregate asphalt concrete, including:

[0069] Preparation of recycled aggregate: Take 5 parts by weight of acrylamide and 0.02 parts by weight of crosslinking agent and dissolve them in 30 parts by weight of water to obtain a mixed solution; place 20 parts by weight of waste concrete blocks with a particle size of 20 - 25 mm in the mixed solution, soak for 10 h, and then dry the moisture to obtain recycled aggregate.

[0070] Preparation of asphalt concrete: Mix 8 parts by weight of an initiator and 10 parts by weight of water to form an initiator solution. Mix the initiator solution, 80 parts by weight of recycled aggregate, 30 parts by weight of quartz sand, and 10 parts by weight of cement evenly to obtain a mixture. Heat 40 parts by weight of asphalt to 160 °C and then add it to the mixture. Stir at a stirring speed of 1000 r / min for 30 min, control the temperature condition at 130 °C during the stirring process, and cool to 75 °C to obtain recycled aggregate asphalt concrete.

[0071] This embodiment also provides a construction method for the above-mentioned recycled aggregate asphalt concrete. Take the recycled aggregate asphalt concrete for the first paving, with a paving thickness of 5 cm, and then roll and level it to a density of 87%. Then carry out the second paving, with a paving thickness of 7 cm, and then roll and level it to a density of 93%.

[0072] Example 2

[0073] This embodiment provides a recycled aggregate asphalt concrete, the components of which include: SBS modified asphalt, initiator ammonium persulfate, quartz sand, cement, water, recycled aggregate;

[0074] Among them, the recycled aggregate is made of waste concrete blocks, acrylamide, and crosslinking agent N,N'-methylenebisacrylamide.

[0075] This embodiment also provides a preparation method for the above-mentioned recycled aggregate asphalt concrete, including:

[0076] Preparation of recycled aggregate: Dissolve 7.5 parts by weight of acrylamide and 0.03 parts by weight of crosslinking agent in water to obtain a mixed solution; soak 20 parts by weight of waste concrete blocks with a particle size of 20 - 25 mm in the mixed solution for 10 h and then dry the moisture to obtain recycled aggregate.

[0077] Preparation of asphalt concrete: Mix 8 parts by weight of an initiator and 10 parts by weight of water to form an initiator solution. Mix the initiator solution, 80 parts by weight of recycled aggregate, 30 parts by weight of quartz sand, and 10 parts by weight of cement evenly to obtain a mixture. Heat 40 parts by weight of asphalt to 160 °C and then add it to the mixture. Stir at a stirring speed of 1000 r / min for 30 min, control the temperature condition at 130 °C during the stirring process, and cool to 75 °C to obtain recycled aggregate asphalt concrete.

[0078] Example 3

[0079] This embodiment provides a recycled aggregate asphalt concrete, the components of which include: SBS modified asphalt, initiator ammonium persulfate, quartz sand, cement, water, recycled aggregate;

[0080] Among them, the recycled aggregate is made of waste concrete blocks, acrylamide, and crosslinking agent N,N'-methylenebisacrylamide.

[0081] This embodiment also provides a preparation method of the above-mentioned recycled aggregate asphalt concrete, including:

[0082] Recycled aggregate preparation: Dissolve 2.5 parts by weight of acrylamide and 0.01 part by weight of cross-linking agent in water to obtain a mixed solution; soak 20 parts by weight of waste concrete blocks with a particle size of 20 - 25 mm in the mixed solution for 10 h and then dry to obtain recycled aggregates.

[0083] Asphalt concrete preparation: Mix 8 parts by weight of initiator and 10 parts by weight of water to make an initiator solution, mix the initiator solution, 80 parts by weight of recycled aggregates, 30 parts by weight of quartz sand and 10 parts by weight of cement evenly to obtain a mixture, heat 40 parts by weight of asphalt to 160 °C and then add it to the mixture, stir at a stirring speed of 1000 r / min for 30 min, control the temperature condition at 130 °C during the stirring process, and cool to 75 °C to obtain recycled aggregate asphalt concrete.

[0084] Example 4

[0085] This embodiment provides a recycled aggregate asphalt concrete, and its components include: SBS modified asphalt, initiator ammonium persulfate, quartz sand, cement, water, recycled aggregates;

[0086] Among them, the recycled aggregates are made of waste concrete blocks, acrylamide, and cross-linking agent N,N'-methylenebisacrylamide.

[0087] This embodiment also provides a preparation method of the above-mentioned recycled aggregate asphalt concrete, including:

[0088] Recycled aggregate preparation: Dissolve 5 parts by weight of acrylamide and 0.02 part by weight of cross-linking agent in water to obtain a mixed solution; soak 20 parts by weight of waste concrete blocks with a particle size of 20 - 30 mm in the mixed solution for 10 h and then dry to obtain recycled aggregates.

[0089] Asphalt concrete preparation: Mix 8 parts by weight of initiator and 10 parts by weight of water to make an initiator solution, mix the initiator solution, 80 parts by weight of recycled aggregates, 30 parts by weight of quartz sand and 10 parts by weight of cement evenly to obtain a mixture, heat 45 parts by weight of asphalt to 160 °C and then add it to the mixture, stir at a stirring speed of 1000 r / min for 30 min, control the temperature condition at 130 °C during the stirring process, and cool to 75 °C to obtain recycled aggregate asphalt concrete.

[0090] Example 5

[0091] This embodiment provides a recycled aggregate asphalt concrete, and its components include: SBS modified asphalt, initiator ammonium persulfate, quartz sand, cement, water, recycled aggregates;

[0092] Among them, the recycled aggregate is made of waste concrete blocks, acrylamide, and crosslinking agent N,N'-methylenebisacrylamide.

[0093] This embodiment also provides a method for preparing the above-mentioned recycled aggregate asphalt concrete, including:

[0094] Preparation of recycled aggregate: Dissolve 5 parts by weight of acrylamide and 0.02 parts by weight of crosslinking agent in water to obtain a mixed solution; soak 20 parts by weight of waste concrete blocks with a particle size of 20 - 25 mm in the mixed solution for 10 h and then dry the moisture to obtain the recycled aggregate.

[0095] Preparation of asphalt concrete: Mix 8 parts by weight of initiator and 10 parts by weight of water to form an initiator solution, mix the initiator solution, 80 parts by weight of recycled aggregate, 30 parts by weight of quartz sand, and 10 parts by weight of cement evenly to obtain a mixture, heat 35 parts by weight of asphalt to 160 °C and then add it to the mixture, stir at a stirring speed of 1000 r / min for 30 min, control the temperature condition at 130 °C during the stirring process, and cool to 75 °C to obtain the recycled aggregate asphalt concrete.

[0096] Comparative Example 1

[0097] This comparative example provides a recycled aggregate asphalt concrete, which is different from Example 1 in that it does not include acrylamide, crosslinking agent, and initiator.

[0098] The above-mentioned method for preparing recycled aggregate asphalt concrete includes:

[0099] Preparation of recycled aggregate: Soak waste concrete blocks with a particle size of 20 - 25 mm in water for 10 h and then dry the moisture to obtain the recycled aggregate.

[0100] Preparation of asphalt concrete: Mix 80 parts by weight of recycled aggregate, 30 parts by weight of quartz sand, 10 parts by weight of cement, and 10 parts by weight of water evenly to obtain a mixture, heat 40 parts by weight of asphalt to 160 °C and then add it to the mixture, stir at a stirring speed of 1000 r / min for 30 min, control the temperature condition at 130 °C during the stirring process, and cool to 75 °C to obtain the recycled aggregate asphalt concrete.

[0101] Comparative Example 2

[0102] This comparative example provides a recycled aggregate asphalt concrete, which is different from Example 1 in that,

[0103] Preparation of asphalt concrete: 8 parts by weight of an initiator and 10 parts by weight of water are mixed to form an initiator solution. The initiator solution, 80 parts by weight of waste concrete blocks, 20 parts by weight of acrylamide, 0.08 parts by weight of a crosslinking agent, 30 parts by weight of quartz sand and 10 parts by weight of cement are mixed evenly to obtain a mixture. 40 parts by weight of asphalt is heated to 160 °C and then added to the mixture, and the mixture is stirred at a stirring speed of 1000 r / min for 30 min. During the stirring process, the temperature condition is controlled at 130 °C, and then cooled to 75 °C to obtain recycled aggregate asphalt concrete.

[0104] Comparative Example 3

[0105] This comparative example provides a recycled aggregate asphalt concrete. The difference from Example 1 is that the asphalt used in this comparative example is ordinary petroleum asphalt (Shell No. 70 road petroleum asphalt).

[0106] Comparative Example 4

[0107] This comparative example provides an asphalt concrete. The differences from Example 1 are as follows:

[0108] 80 parts by weight of limestone gravel (particle size 20 - 25 mm), 30 parts by weight of quartz sand and 10 parts by weight of cement are mixed evenly to obtain a mixture. 40 parts by weight of asphalt is heated to 160 °C and then added to the mixture, and the mixture is stirred at a stirring speed of 1000 r / min for 30 min. During the stirring process, the temperature condition is controlled at 130 °C, and then cooled to 75 °C to obtain asphalt concrete.

[0109] Test Example

[0110] (1) According to the "Test Regulations for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20—2011), the dynamic stability (times / mm) of the recycled aggregate asphalt concrete of Examples 1 - 5 and Comparative Examples 1 - 3 at 60 °C was detected, and the results are shown in Table 1.

[0111] (2) According to the "Technical Specifications for Construction of Highway Asphalt Pavements" (JTG F40 - 2004), the immersion residual stability of the recycled aggregate asphalt concrete of Examples 1 - 5 and Comparative Examples 1 - 3 was detected, and the results are shown in Table 1.

[0112] Table 1 Performance test results of Examples 1 - 5 and Comparative Examples 1 - 3

[0113] Data source Dynamic stability (times / mm) Immersion residual stability (%) Example 1 3120 93.1 Example 2 3070 92.5 Example 3 2860 90.6 Example 4 2980 91.7 Example 5 2930 91.3 Comparative example 1 1670 60.5 Comparative example 2 2180 78.8 Comparative example 3 2640 89.2 Comparative example 4 2790 87.6％

[0114] The dynamic stability of Examples 1-5 reached over 2,800 times / mm, and the immersion residual stability was higher than 90%, indicating that the recycled aggregate asphalt concrete of Examples 1-5 had a relatively good level of both high-temperature stability and water stability. After replacing the SBS modified asphalt with ordinary petroleum asphalt in Comparative Example 3, both the high-temperature stability and water stability decreased to a certain extent. It was analyzed that when using SBS modified asphalt, the three-dimensional cross-linked network formed by acrylamide, initiator, and cross-linking agent in the recycled aggregate asphalt concrete had good compatibility with SBS particles, and the combined action of the three-dimensional cross-linked network and SBS particles was conducive to improving the overall stability of the recycled aggregate asphalt concrete.

[0115] Taking Example 1 as a control, the dynamic stability and immersion residual stability of Comparative Example 1 were much lower than those of Example 1. It was analyzed that in Example 1, the waste concrete blocks formed recycled aggregates under the action of acrylamide, initiator, and cross-linking agent, repaired a large number of microcracks existing on the surface and inside of the waste concrete blocks, and formed a protective layer on the surface of the waste concrete blocks, as much as possible avoiding the weakening of the bond between the microcracks of the waste concrete blocks and other components caused by water intrusion during immersion, thereby improving the immersion residual stability. And while improving the bearing capacity of the waste concrete blocks, a three-dimensional cross-linked network was formed inside the asphalt concrete, further improving the integrity of the recycled aggregates and asphalt, and comprehensively improving the dynamic stability.

[0116] The dynamic stability and immersion residual stability of Comparative Example 2 were much lower than those of Example 1, but higher than those of Comparative Example 1. Compared with Comparative Example 2, it was analyzed that in Example 1, acrylamide and cross-linking agent were first added to the waste concrete blocks to penetrate the microcracks and coat the surface, thereby strengthening all the waste concrete blocks and at the same time improving the uniformity of the distribution of acrylamide, initiator, and cross-linking agent in the recycled aggregate asphalt concrete. The defect of Comparative Example 2 was that acrylamide, initiator, and cross-linking agent had poor dispersibility, could only strengthen part of the waste concrete, and was difficult to penetrate into the microcracks.

[0117] In summary, the recycled aggregate asphalt concrete of the present invention uses recycled aggregates made of waste concrete blocks, acrylamide, and a cross-linking agent to replace conventional coarse aggregates. The acrylamide and the cross-linking agent form a protective layer on the surface of the waste concrete blocks and penetrate into the microcracks. When the recycled aggregates are mixed with other components, the acrylamide and the cross-linking agent in the microcracks react through polymerization and cross-linking upon contact with water and an initiator, adhering to the inner walls on both sides of the microcracks inside the microcracks, thereby repairing and strengthening the waste concrete blocks, improving the integrity of the recycled aggregate asphalt concrete, and enhancing the stability of the recycled aggregate asphalt concrete. The performance of the recycled aggregate asphalt concrete of the present invention is higher than that of traditional non-recycled aggregate asphalt concrete. The dynamic stability of the recycled aggregate asphalt concrete of the present invention reaches 3,120 times / mm, and the immersion residual stability is 93.1%.

[0118] The above has made a detailed description in conjunction with the embodiments of the present invention, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art to which the present invention pertains, various changes can be made without departing from the gist of the present invention.

Claims

1. A recycled aggregate asphalt concrete, characterized in that: The composition comprises the following components calculated by weight: 35-45 parts of asphalt; 70-90 parts of recycled aggregate; 5-10 parts of initiator; 25-35 parts of quartz sand; 5-15 parts of cement; 8-12 parts water; The recycled aggregate is made of waste concrete blocks, acrylamide and a cross-linking agent.

2. The recycled aggregate asphalt concrete according to claim 1, characterized in that: The cross-linking agent includes at least one of N,N′-methylenebisacrylamide, trimethylolpropane triacrylate and ethylene glycol dimethacrylate; preferably, the mass ratio of the acrylamide to the cross-linking agent is 1:0.003-0.005; preferably, in the recycled aggregate, the mass percentage of the acrylamide and the cross-linking agent to the waste concrete block is 8%-55%.

3. The recycled aggregate asphalt concrete according to claim 1 or 2, characterized in that: The recycled aggregate comprises the following components calculated by weight: 15-25 pieces of discarded concrete blocks; 2-8 parts of acrylamide; Cross-linking agent 0.01-0.03 parts.

4. The recycled aggregate asphalt concrete according to claim 1, characterized in that: The initiator includes at least one of ammonium persulfate, potassium persulfate and sodium persulfate; preferably, the asphalt is SBS modified asphalt; preferably, the amount of the initiator is 5%-10% of the mass of the recycled aggregate.

5. A method for preparing recycled aggregate asphalt concrete according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: S1. dissolving acrylamide and a cross-linking agent to obtain a mixed solution; soaking the waste concrete blocks in the mixed solution, and drying to obtain recycled aggregate; S2. Mix an initiator and water to prepare an initiator solution, mix the initiator solution, the recycled aggregate, quartz sand and cement to obtain a mixture, heat asphalt and stir it with the mixture to obtain recycled aggregate asphalt concrete.

6. The preparation method according to claim 5, characterized in that: In step S1, the particle size of the waste concrete blocks is 20-25 mm; preferably, in step S1, the soaking time is 8-12 hours.

7. The preparation method according to claim 5, characterized in that: In step S2, the temperature of the asphalt after heating is 155-180°C; preferably, in step S2, the stirring speed is 800-1200r / min; preferably, in step S2, the stirring time is 20-40min; preferably, in step S2, the stirring temperature is 125-135°C.

8. The preparation method according to claim 5, characterized in that: In step S2, the stirring is followed by cooling to 70-80°C.

9. A construction method of recycled aggregate asphalt concrete according to any one of claims 1 to 4, characterized in that: include: The recycled aggregate asphalt concrete is spread for the first time and then rolled to make it smooth. It is then spread for the second time and then rolled to make it smooth until the compaction degree meets the standards.

10. Use of the recycled aggregate asphalt concrete according to any one of claims 1 to 4 in an asphalt concrete structure.