Solidified wearing layer mixture doped with RAP fine separation material and preparation method of solid wearing layer mixture

Abstract

The invention provides a seepage and solid wearing layer mixture doped with an RAP refined separation material and a preparation method of the seepage and solid wearing layer mixture, and belongs to the technical field of road materials. The solid permeation wearing layer mixture comprises the following raw materials in parts by mass: 30-50 parts of RAP refined separation material, 47-68 parts of new aggregate, 10-12 parts of polymer modified high-viscosity emulsified asphalt, 1-3 parts of filler and 5-8 parts of water; wherein the total amount of the RAP fine separation material, the new aggregate and the filler is 100 parts. According to the invention, large-scale oilstone fine separation equipment is adopted, the RAP is subjected to physical collision, oilstone fine separation is carried out, the RAP of 3-8mm is separated from the conventional RAP and is used for replacing a part of new aggregate, the problem of reutilization of a large amount of waste asphalt mixture is effectively solved, resource waste is reduced, and the sustainable utilization efficiency of asphalt resources is improved. According to the present invention, the solid permeation wearing layer mixture has characteristics of long mixing time, improved cohesive force, small sand adhesion amount of the load wheel, wet wheel wear loss far less than the technical requirement, and improved road performance.

Description

Technical Field

[0001] The invention belongs to the technical field of road materials, and in particular relates to a RAP fine material-added infiltration and consolidation wear layer mixture and a preparation method thereof. Background Art

[0002] At present, the scale of road construction has reached a new height worldwide. The lack of high-quality building materials in road construction has attracted the attention of engineering researchers in many countries. At the same time, facing the problems of construction cost and environmental pollution, how to use sustainable and alternative building materials has become a current research hotspot. In the process of road engineering reconstruction and expansion, the old asphalt pavement will be demolished to produce old asphalt pavement materials. If this part of the material is used in the new asphalt pavement with appropriate construction technology, it will not only solve the problem of construction waste disposal, but also save some natural aggregates. The promotion and application of recycled asphalt pavement materials (RAP) will have broad application prospects in reducing costs, protecting the environment, and saving resources. It is a construction technology that kills two birds with one stone. As highway construction enters the era of comprehensive maintenance, my country produces nearly 200 million tons of recycled asphalt mixture (RAP) every year during major and medium maintenance. The efficient resource recycling of RAP has become a development trend of highway maintenance.

[0003] Agglomeration and variability are two main characteristics of reclaimed asphalt pavement (RAP). The performance of recycled asphalt mixture is largely affected by the variability of RAP. Studies have shown that RAP agglomeration will cause serious pseudo-particle size and large gradation variability of RAP, which will lead to unstable gradation of RAP, increasing the difficulty of designing the composition of recycled mixture. The variability of RAP is affected by many factors such as the traffic load of the original pavement, the aging degree of asphalt on different pavements, material composition, gradation characteristics, milling equipment, milling temperature, pavement humidity and number of pavement layers. After the old asphalt pavement is milled, the aged asphalt mortar adheres to the surface of RAP aggregate, resulting in a large number of particles containing aged asphalt, mineral powder and fine aggregates agglomerating to form RAP agglomerates. RAP agglomeration will not only increase the variability of recycled asphalt mixture, but also reduce the low temperature performance, fatigue performance and water stability of the mixture.

[0004] In order to overcome these problems, the existing large-scale oilstone fine separation equipment is used to finely separate RAP through physical collision. Conventional RAP can be separated into five grades of materials (collectively referred to as RAP fine separation materials) of 25-16mm, 10-16mm, 5-10mm, 3-5mm, and 0-3mm, solving the problem of large variability of RAP materials. Among them, coarse aggregates (above 3mm) with poor oil content (oil content ≤ 2%) can be directly used as new aggregates to achieve high-value applications, and 0-3mm fine powder has great recycling value due to its oil-rich characteristics (generally 7%). On this basis, according to actual needs, 3-8mm fine separation materials can also be obtained by adjusting the equipment screen.

[0005] In the preventive maintenance of highways, it is necessary to adopt appropriate maintenance measures in combination with the severity of highway diseases and the situation of increased traffic volume. Among them, the maintenance measures of the permeable wear layer have the advantages of low maintenance cost, strong durability, and good friction resistance. It can effectively improve the road performance of the original road surface, ensure the comfort of road driving, and reduce the occurrence of typical diseases.

[0006] The solid wearing layer is sprayed with a solidifying agent on the original road surface in advance to restore the performance of the aged asphalt on the original road surface and increase the bonding between layers. Then, a paver is used to mix polymer-modified high-viscosity emulsified asphalt, filler (generally cement), aggregate, water and additives in an approved proportion to form a slurry asphalt material and spread it on the road. This can quickly restore traffic and form a topcoat with good anti-skid and durability properties.

[0007] During the use of highways, the road surface is prone to early disease problems, such as cracks, rutting, potholes, etc. Under normal circumstances, pavement maintenance technologies can be divided into three categories: first, crack filling; second, preventive maintenance such as surface sealing or overlay; third, corrective maintenance and repair. In order to reduce pavement damage and improve pavement performance, preventive maintenance measures can be adopted in time when the pavement has minor diseases. At present, there are many commonly used preventive maintenance measures for asphalt pavements, such as micro-surfacing, slurry sealing, thin layer overlay, super-viscous wear layer, etc. The penetrant of the infiltration wear layer can penetrate downward well, with a depth of 3cm to 4cm, and flow back to the wear layer to form a three-dimensional network structure layer. Compared with other preventive maintenance technologies, the application of the infiltration wear layer technology can not only improve the various properties of the aging asphalt of the original pavement, but also repair rutting diseases, while also having environmental and economic benefits.

[0008] Among the existing patents, there are currently few domestic patents related to infiltration wear layers. The only patents, such as "Maintenance and construction method of infiltration wear layer of asphalt pavement" (CN201711310453.4), "A kind of infiltration regeneration type ultra-thin wear layer and its construction method" (CN202111281714.0), "A regeneration type anti-skid and low-noise wear layer and its construction method" (CN202210022479.3), "A kind of anti-icing wear layer and maintenance construction method of asphalt pavement" (CN202110576260.3), etc., do not use RAP materials.

[0009] Therefore, developing a method for preparing a solidified wearing layer mixture that can efficiently utilize RAP materials has important practical significance and broad application prospects. Summary of the invention

[0010] The purpose of the present invention is to provide a RAP finely divided material-added infiltration wear course mixture and a preparation method thereof, by efficiently utilizing waste asphalt mixture (RAP) and applying it to the infiltration wear course to improve the road performance of the mixture, reduce the cost of highway engineering, and realize the sustainable utilization of resources.

[0011] In order to achieve the above object, the present invention provides the following technical solutions:

[0012] A RAP fine-graded material-added infiltration and consolidation wear layer mixture comprises the following raw materials in parts by weight: 30-50 parts of RAP fine-graded material, 47-68 parts of new aggregate, 10-12 parts of polymer-modified high-viscosity emulsified asphalt, 1-3 parts of filler, and 5-8 parts of water; wherein the total amount of the RAP fine-graded material, the new aggregate, and the filler is 100 parts.

[0013] Furthermore, the RAP refined material is the recycled aggregate after the waste asphalt mixture is separated from the oilstone, with a particle size of 3-8mm and an asphalt content of ≤2%.

[0014] The present invention uses RAP fine-graded materials to replace part of the new aggregates, which can firstly significantly reduce the problem of handling construction waste, improve the sustainable utilization efficiency of resources, and reduce the cost of highway projects. Secondly, RAP fine-graded materials can improve the bonding force between asphalt and aggregates and enhance the overall stability of the mixture; after the aged asphalt in the RAP fine-graded materials is treated, the negative impact of unfavorable indicators can be reduced, and favorable indicators with positive impact can be retained; the addition of RAP fine-graded materials can extend the mixing time of the mixture, improve the flexibility of construction, improve the fluidity and construction performance of the mixture, and reduce the difficulty of construction. In addition, RAP fine-grained materials with a particle size of 3-8mm can be better mixed with new aggregates (0-3mm) and other fillers to form a reasonable gradation and improve the density and stability of the mixture; 3-8mm fine-grained materials can be combined with 0-3mm new aggregates to form a dense gradation structure, reduce the intrusion of air and moisture, and improve the durability of the mixture; the appropriate particle size makes the mixture have good fluidity and construction performance, which is convenient for paving and compaction, reduces construction difficulty, shortens construction time, and improves construction quality.

[0015] Furthermore, the new aggregate is basalt fine aggregate with a particle size of 0-3 mm.

[0016] Furthermore, the raw materials for preparing the polymer modified high-viscosity emulsified asphalt include, by mass, 100 parts of asphalt, 5-10 parts of SBS (styrene-butadiene-styrene copolymer), 2-4 parts of emulsifier, 1-3 parts of stabilizer, 0.5-1.5 parts of antioxidant, 1-3 parts of plasticizer, 0.5-1.5 parts of nano-silicon dioxide, 0.5-1.5 parts of non-ionic surfactant, and 30-40 parts of water.

[0017] Furthermore, the emulsifier is one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium salt of alkylphenol polyoxyethylene ether sulfate, and sodium salt of fatty alcohol sulfate; the stabilizer is one or more of polyacrylate, polyvinyl alcohol, sodium carboxymethyl cellulose, and hydroxyethyl cellulose; the antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant BHT, antioxidant 1076, and antioxidant DLTP; the plasticizer is one or more of dibutyl phthalate, dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, and diisobutyl phthalate; the nonionic surfactant is one or more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and polyoxyethylene sorbitan fatty acid ester.

[0018] Furthermore, the preparation method of the polymer modified high-viscosity emulsified asphalt comprises the following steps:

[0019] (1) Heat the asphalt to 140-160°C to make it completely melted, add SBS to the melted asphalt, and stir to fully disperse the polymer;

[0020] (2) Mix the emulsifier and stabilizer evenly and set aside;

[0021] (3) heating water to 60-70° C., adding antioxidant, plasticizer, nano-silica and non-ionic surfactant, stirring evenly to prepare an aqueous phase solution;

[0022] (4) The prepared aqueous phase solution and the mixture of the emulsifier and the stabilizer are added to the asphalt containing the polymer, and emulsified and stirred using a high-speed shear mixer to obtain a polymer-modified high-viscosity emulsified asphalt.

[0023] Furthermore, in step (4), the rotation speed of the high-speed shear mixer is 10000-15000 rpm, and the stirring time is 20-40 minutes.

[0024] The polymer-modified high-viscosity emulsified asphalt of the present invention is one of the key components of the penetration and consolidation wear layer mixture. The polymer-modified high-viscosity emulsified asphalt significantly improves the viscosity of asphalt by adding SBS. High-viscosity asphalt is not easy to flow at high temperatures and is not easy to crack at low temperatures, thereby improving the temperature sensitivity of asphalt, so that it can maintain good performance under different temperature conditions. The polymer-modified high-viscosity emulsified asphalt can enhance the bonding force between asphalt and aggregate. Stronger bonding force means that the overall stability of the mixture is better, and it can better resist the influence of traffic loads and environmental factors, and extend the service life of the road surface. The addition of polymer-modified high-viscosity emulsified asphalt can increase the mixing time of the mixture, which is helpful for operation during the construction process. The emulsified asphalt has better flexibility and wear resistance under low temperature conditions, and can reduce the risk of low-temperature cracking.

[0025] Furthermore, the filler is selected from one or more of cement, mineral powder, lime, diatomaceous earth and kaolin.

[0026] The present invention also provides a method for preparing the above-mentioned RAP fine material-added infiltrated wear layer mixture, which comprises the step of mixing the raw materials.

[0027] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0028] 1. Efficient utilization of large amounts of waste asphalt mixture (RAP): The present invention adopts large-scale oil-stone fine separation equipment to perform physical collision on RAP for fine separation of oil and stone, separates 3-8 mm RAP (RAP fine fraction) from conventional RAP, and uses the 3-8 mm fine fraction to replace part of the new aggregate in the infiltration and consolidation wear layer, effectively solving the problem of recycling a large amount of waste asphalt mixture, reducing resource waste, and improving the sustainable utilization efficiency of asphalt resources.

[0029] 2. Reduce the amount of new asphalt and new aggregate: Use RAP fine material to replace part of the new aggregate, and the mixing ratio is 30-50%, which reduces the use of new asphalt and new aggregate and effectively reduces the cost of highway projects.

[0030] 3. It can improve the various properties of aged asphalt on the original road surface: it can repair rutting damage, and has strong durability and good friction resistance. It can effectively improve the road performance of the original road surface, ensure the comfort of driving on the road, and reduce the occurrence of typical diseases.

[0031] 4. Improved road performance: Compared with the infiltrated wear layer mixture without fine-grained materials, the infiltrated wear layer mixture with RAP fine-grained materials can be mixed for a long time, has improved cohesion, has a smaller amount of sand adhered to the loaded wheels, and the wet wheel wear loss is far less than the technical requirements. That is, the infiltrated wear layer mixture obtained by partially replacing new aggregate with RAP fine-grained materials has improved road performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the gradation curve of the solidified wear layer in Example 1.

[0033] Figure 2 This is the curve of the 1-hour wet wheel wear value changing with the oilstone ratio in Test Example 1.

[0034] Figure 3 This is the curve of the amount of sand stuck to the load wheel changing with the oilstone ratio in Test Example 1.

[0035] Figure 4 Schematic diagram of the optimal oil-stone ratio of the solid wear layer in Test Example 1. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The raw materials used in the present invention are all common commercially available products, and the following is an exemplary description:

[0038] 3-8mm finely divided materials were purchased from Lianyungang Jinshun Recycling Resources Utilization Co., Ltd.:

[0039] 0-3 mm basalt fine aggregate was purchased from Tianchang Xiangyu Mining Co., Ltd.;

[0040] Asphalt was purchased from Sinopec, AH-70;

[0041] SBS (styrene-butadiene-styrene copolymer) was purchased from Sinopec Baling Petrochemical Co., Ltd., YH-792;

[0042] Polyacrylate was purchased from Jiangsu Zhongjiang Chemical Co., Ltd., ZJ-AC-100;

[0043] Nano-silica was purchased from Nanjing Xianfeng Nanomaterials Technology Co., Ltd., AF-NS100;

[0044] Portland cement was purchased from Lianyungang Banzhuang Cement Co., Ltd., PO42.5;

[0045] Glass beads were purchased from Jiangsu Huachang Glass Bead Co., Ltd., HC-GB-01;

[0046] SBR (styrene butadiene rubber) was purchased from Beijing Yanshan Petrochemical Co., Ltd., 1502.

[0047] Example 1

[0048] The present embodiment provides a solidified wearing layer mixture mixed with RAP fine material, comprising the following raw materials in parts by weight: 36 parts of RAP fine material, 62 parts of new aggregate, 11.1 parts of polymer-modified high-viscosity emulsified asphalt, 2 parts of filler, and 6 parts of water.

[0049] The preparation method of the mixture comprises: mixing RAP fine material and new aggregate evenly to obtain mixed aggregate; heating polymer-modified high-viscosity emulsified asphalt to 60-70° C., then adding it to the mixed aggregate together with water and filler, and stirring for 30 seconds using a high-speed mixer (rotation speed 1200 rpm) to ensure that the emulsified asphalt is evenly distributed in the aggregate, thereby obtaining a solidified wearing layer mixture.

[0050] The raw materials for preparing the polymer modified high-viscosity emulsified asphalt include the following components by mass: 100 parts of asphalt, 8 parts of SBS, 3 parts of emulsifier (sodium dodecyl sulfate), 2 parts of stabilizer (polyacrylate), 1 part of antioxidant (antioxidant 1010), 2 parts of plasticizer (dibutyl phthalate), 1 part of nano-silica, 1 part of non-ionic surfactant (alkylphenol polyoxyethylene ether OP-10), and 35 parts of water.

[0051] The preparation method of the polymer modified high-viscosity emulsified asphalt comprises the following steps:

[0052] (1) heating the asphalt to 150° C. to completely melt it, adding SBS to the melted asphalt, stirring to fully disperse the polymer, and obtaining asphalt containing the polymer for later use;

[0053] (2) mixing the emulsifier and the stabilizer uniformly to obtain a mixture of the emulsifier and the stabilizer for later use;

[0054] (3) heating water to 66° C., adding an antioxidant, a plasticizer, nano-silica and a nonionic surfactant, and stirring uniformly to prepare an aqueous phase solution;

[0055] (4) The prepared aqueous phase solution and the mixture of the emulsifier and the stabilizer are added to the asphalt containing the polymer, and emulsified using a high-speed shear mixer at a rotation speed of 12,000 rpm for 30 minutes to obtain a polymer-modified high-viscosity emulsified asphalt.

[0056] The technical index requirements and test results of polymer modified high-viscosity emulsified asphalt are shown in Table 1.

[0057] Table 1 Technical index requirements and test results of polymer modified high viscosity emulsified asphalt

[0058]

[0059]

[0060] The RAP fine material is produced by using large-scale oilstone fine separation equipment to physically collide RAP to perform oilstone fine separation, and separate conventional RAP into 3-8mm RAP fine material with an asphalt content of 1.5%. The technical index requirements and test results of RAP fine material are shown in Table 2.

[0061] Table 2 Technical index requirements and test results of RAP fine materials

[0062] Test items unit Test results Technical requirements Apparent density <![CDATA[g / cm 3 ]]> 2.883 ≮2.6 Water absorption ％ 0.35 ≯2.0 Crushing value ％ 10.5 ≯26 Los Angeles Abrasion Value ％ 13.1 ≯28 Needle-like particle content ％ 5.0 ≯15 Weak particle content ％ 0.67 ≯3.0 Adhesion to asphalt - Level 5 ≮Level 4

[0063] The new aggregate is basalt fine aggregate with a particle size of 0-3mm. The technical index requirements and test results of basalt fine aggregate are shown in Table 3.

[0064] Table 3 Technical index requirements and test results of Wuyan fine aggregate

[0065]

[0066]

[0067] The filler is ordinary Portland cement PO42.5.

[0068] The results of the water washing and screening tests of RAP fine material, new aggregate and filler are shown in Table 4.

[0069] Table 4 Results of mineral material washing and screening test

[0070]

[0071] According to the indoor screening results of the mineral materials used for the infiltration wear layer, the gradation requirements of the infiltration wear layer and previous construction experience, the gradation composition of the infiltration wear layer was carried out, and finally the mineral material ratio of 0-2.36mm:3-8mm:filler=62:36:2 was determined. The specific gradation composition is shown in Table 5, and the gradation curve is shown in Figure 1 .

[0072] Table 5 Synthetic gradation of mineral materials for infiltration and solidification of wear layer

[0073]

[0074]

[0075] Test Example 1

[0076] In this test example, according to the RAP fine material-added infiltrated wear layer mixture prepared in Example 1, the amount of polymer-modified high-viscosity emulsified asphalt was changed, and a reasonable oil-stone ratio (the mass percentage of emulsified asphalt to mineral material) was determined through wet wheel wear test, load wheel sand adhesion test, mixing test and cohesion test.

[0077] The technical index requirements for the infiltration and consolidation wear layer mixture are shown in Table 6:

[0078] Table 6 Technical index requirements for the infiltration and consolidation wear layer mixture

[0079]

[0080] 1. Wet Wheel Abrasion Test (WTAT)

[0081] The wet wheel wear test simulates the wear between vehicle tires and road surfaces to test whether the designed mixture ratio can meet the needs of vehicle wear. The focus is to test whether the asphalt content in the solid wear layer is sufficient. The wet wheel wear test is carried out according to the prescribed molding method. The molded mixture specimen is placed in water and worn with a wear head for 5 minutes to measure the wear loss. The WTAT value of the solid wear layer after immersion in water for 1 hour is required to be less than 540g / ㎡. According to the synthetic grading of the solid wear layer mineral materials in Table 5, five different oil-stone ratios are set with an estimated oil-stone ratio of 7.0% (pure asphalt) as the center, and the upper and lower floating angles of ±0.5% and ±1% are set to make wet wheel wear test specimens. A 1-hour wet wheel wear test is carried out. The WTAT test results are shown in Table 7; the relationship curve of the 1-hour wet wheel wear value with the oil-stone ratio is shown in Table 7. Figure 2 .

[0082] Table 7 1 hour WTAT test results of the solidified wearing layer mixture

[0083] Oil-stone ratio (%) 6.0 6.5 7.0 7.5 8.0 Abrasion value (g / ㎡) 687.1 435.3 171.4 100.8 79.3

[0084] Note: The oil-stone ratio in the table refers to the ratio of base asphalt to dry mineral aggregate (RAP fine material, new aggregate and filler).

[0085] Depend on Figure 2 It is found that the minimum oil-stone ratio of the solid wear layer mixture is 6.20%.

[0086] 2. Load wheel sand test (LWT)

[0087] Excessive asphalt dosage can easily cause road waves and oil spills. The load wheel sand adhesion test is used to determine the maximum asphalt dosage of the infiltration wear layer mixture, and together with the wet wheel wear test, it determines the optimal dosage of emulsified asphalt. It uses the adhesion of hot sand on the surface of the mixture as the inspection standard, requiring that the sand adhesion test value should be less than 450g / ㎡, and the wheel track width change rate should be less than 5%. According to the synthetic gradation of the infiltration wear layer mineral material in Table 5, with the estimated oil-stone ratio of 7.0% (pure asphalt) as the center, five different oil-stone ratios are set with floating upper and lower values ​​of ±0.5% and ±1%, respectively, to make specimens for the load wheel sand adhesion test. The load wheel sand adhesion test was carried out. The LWT test results are shown in Table 8; the relationship curve between the load wheel adhesion sand amount and the oil-stone ratio is shown in Figure 3 .

[0088] Table 8 Test results of sand adhesion of load wheel in the mixture of infiltration and consolidation wear layer

[0089] Oil-stone ratio (%) 6.0 6.5 7.0 7.5 8.0 Sand sticking amount (g / ㎡) 93.9 187.9 333.5 482.0 690.1

[0090] Note: The oil-stone ratio in the table refers to the ratio of base asphalt to dry mineral aggregate (RAP fine material, new aggregate and filler).

[0091] Depend on Figure 3 It is found that the maximum oil-stone ratio of the solid-infiltrated wearing layer mixture is 7.29%.

[0092] 3. Determination of the optimal oil-stone ratio

[0093] The optimum oil-stone ratio of the infiltration-solidification wear layer mixture is determined by a 1-hour wet wheel abrasion test and a load wheel sand adhesion test. Figure 4 The minimum oil-to-stone ratio is determined by the 1h wet wheel wear test, and the maximum oil-to-stone ratio is determined by the load wheel sand adhesion test to ensure the oil-to-stone ratio required for the infiltration and consolidation of the wear layer.

[0094] According to the results of the mix design test, the optimal oil-stone ratio of the project's solid wearing layer mixture is determined to be 6.8% based on full consideration of the asphalt content in the RAP refined material, the original road conditions, climate and traffic factors. Since the evaporation residue content of the polymer-modified high-viscosity emulsified asphalt is 61.5%, the optimal emulsified asphalt dosage is 11.1%.

[0095] Test Example 2

[0096] In this test example, the solidified wearing layer mixture of Example 1 was subjected to mixing test, 1h wet wheel abrasion test, 6d wet wheel abrasion test, load wheel sand adhesion test and cohesion test according to the requirements of "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The test results are shown in Table 9.

[0097] Table 9 Test results of solid wear layer mixture

[0098]

[0099] Comparative Example 1

[0100] The difference between this comparative example and Example 1 is that the RAP finely divided material is replaced with new aggregate, that is, a RAP-free infiltrated wearing layer mixture is prepared.

[0101] Comparative Example 2

[0102] The difference between this comparative example and Example 1 is that the RAP finely divided material with a particle size of 3-8 mm is replaced by the RAP finely divided material with a particle size of 5-10 mm.

[0103] Comparative Example 3

[0104] The difference between this comparative example and Example 1 is that the nano-silica in the raw material for preparing the polymer-modified high-viscosity emulsified asphalt is replaced by glass microspheres.

[0105] Comparative Example 4

[0106] The difference between this comparative example and Example 1 is that the SBS in the raw material for preparing the polymer-modified high-viscosity emulsified asphalt is replaced by SBR (styrene-butadiene rubber).

[0107] Comparative Example 5

[0108] The difference between this comparative example and Example 1 is that the alkylphenol polyoxyethylene ether in the raw material for preparing the polymer-modified high-viscosity emulsified asphalt is replaced by hexadecyltrimethylammonium bromide.

[0109] Test Example 3

[0110] In this test example, the solidified wear layer mixtures of Example 1 and Comparative Examples 1-5 were subjected to mixing test, 1h wet wheel abrasion test, 6d wet wheel abrasion test, load wheel sand adhesion test and cohesion test according to the requirements of "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The test results are shown in Table 10.

[0111] Table 10 Test results of solid wear layer mixture

[0112]

[0113]

[0114] The above results show that the infiltration and consolidation wear layer mixture prepared by the present invention can be mixed for a long time, has high cohesion, has a small amount of sand adhered to the loaded wheel, and the wet wheel wear loss is far less than the technical requirements.

[0115] In Comparative Example 1, RAP fine-graded material is lacking, and various road performances of the infiltration wear layer are reduced. It can be seen that the present invention uses RAP fine-graded material to replace part of the new aggregate, which not only reduces the cost of highway engineering, but also improves the road performance. In Comparative Example 2, RAP fine-graded material with a particle size of 3-8 mm is replaced with RAP fine-graded material with a particle size of 5-10 mm. The RAP fine-graded material with a larger particle size increases the void ratio of the mixture, affects the density and stability of the mixture, and also causes uneven distribution of asphalt, affecting the overall performance of the mixture. In Comparative Example 3, nano-silica in the raw material for preparing polymer-modified high-viscosity emulsified asphalt is replaced with glass microspheres. Although glass microspheres are lightweight and reflective, their oil absorption and adsorption are not as good as nano-silica, which affects the stability and durability of the mixture. In Comparative Example 4, SBS in the raw material for preparing polymer-modified high-viscosity emulsified asphalt is replaced with SBR. SBR may affect the viscosity and adhesion of asphalt, resulting in a decrease in the overall performance of the mixture. In Comparative Example 5, the alkylphenol polyoxyethylene ether in the preparation raw material of the polymer-modified high-viscosity emulsified asphalt is replaced with cetyltrimethylammonium bromide. Cetyltrimethylammonium bromide is a cationic surfactant. Its emulsification and dispersion properties in the formula of the present invention are not as good as those of alkylphenol polyoxyethylene ether, resulting in a decrease in the performance of the mixture.

[0116] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A RAP fine material-added infiltration and consolidation wear layer mixture, comprising the following raw materials by weight: 30-50 parts of RAP fine material, 47-68 parts of new aggregate, 10-12 parts of polymer-modified high-viscosity emulsified asphalt, 1-3 parts of filler, and 5-8 parts of water; wherein: The total amount of RAP fine material, new aggregate and filler is 100 parts.

2. The solidified wearing layer mixture according to claim 1, characterized in that: The RAP refined material is the recycled aggregate after the waste asphalt mixture is separated from the oilstone, with a particle size of 3-8mm and an asphalt content of ≤2%.

3. The solidified wearing layer mixture according to claim 1, characterized in that: The new aggregate is basalt fine aggregate with a particle size of 0-3 mm.

4. The solidified wearing layer mixture according to claim 1, characterized in that: The raw materials for preparing the polymer modified high-viscosity emulsified asphalt include, by weight, 100 parts of asphalt, 5-10 parts of SBS, 2-4 parts of emulsifier, 1-3 parts of stabilizer, 0.5-1.5 parts of antioxidant, 1-3 parts of plasticizer, 0.5-1.5 parts of nano-silicon dioxide, 0.5-1.5 parts of non-ionic surfactant, and 30-40 parts of water.

5. The solidified wearing layer mixture according to claim 4, characterized in that: The emulsifier is one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium salt of alkylphenol polyoxyethylene ether sulfate, and sodium salt of fatty alcohol sulfate; the stabilizer is one or more of polyacrylate, polyvinyl alcohol, sodium carboxymethyl cellulose, and hydroxyethyl cellulose; the antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant BHT, antioxidant 1076, and antioxidant DLTP.

6. The solidified wearing layer mixture according to claim 4, characterized in that: The plasticizer is one or more of dibutyl phthalate, dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, and diisobutyl phthalate; the nonionic surfactant is one or more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and polyoxyethylene sorbitan fatty acid ester.

7. The solidified wearing layer mixture according to claim 4, characterized in that: The preparation method of the polymer modified high-viscosity emulsified asphalt comprises the following steps: (1) Heat the asphalt to 140-160°C to make it completely melted, add SBS to the melted asphalt, and stir to fully disperse the polymer; (2) Mix the emulsifier and stabilizer evenly and set aside; (3) heating water to 60-70° C., adding antioxidant, plasticizer, nano-silica and non-ionic surfactant, stirring evenly to prepare an aqueous phase solution; (4) The prepared aqueous phase solution and the mixture of the emulsifier and the stabilizer are added to the asphalt containing the polymer, and emulsified and stirred using a high-speed shear mixer to obtain a polymer-modified high-viscosity emulsified asphalt.

8. The solidified wearing layer mixture according to claim 7, characterized in that: In step (4), the rotation speed of the high-speed shear mixer is 10000-15000 rpm, and the stirring time is 20-40 minutes.

9. The solidified wearing layer mixture according to claim 1, characterized in that: The filler is selected from one or more of cement, mineral powder, lime, diatomaceous earth and kaolin.

10. A method for preparing a solidified wearing layer mixture according to any one of claims 1 to 9, characterized in that: The method comprises the step of mixing the raw materials.

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