Modified asphalt, asphalt wearing layer with drainage and noise reduction functions and construction method

Abstract

The application belongs to the technical field of polymer materials, and discloses a modified asphalt, an asphalt wearing layer with a drainage and noise reduction function and a construction method.The modified asphalt comprises 100 parts of asphalt, 6-10 parts of a thermoplastic elastomer, 4-8 parts of silane cross-linked polyethylene, 2-6 parts of allyl resin, 2-6 parts of acrylic-2-ethyl ethyl ester and 0.3-1 parts of a stabilizer according to mass fractions.The synergistic effect among the three components of silane cross-linked polyethylene, allyl resin and acrylic-2-ethyl ethyl ester enables the modified asphalt to have excellent aging resistance and oil stain resistance.The wearing layer prepared from the modified asphalt has good drainage and noise reduction functions and also has aging resistance and oil stain resistance.

Description

Technical Field

[0001] This invention belongs to the field of asphalt material technology, specifically relating to a modified asphalt, an asphalt wearing course with drainage and noise reduction functions, and a construction method. Background Technology

[0002] Thin-layer asphalt overlay, a common technique for preventative highway maintenance, primarily enhances the anti-skid function of the pavement surface, protects the original pavement, prevents the aging of the original asphalt, and forms a water-blocking layer to prevent surface water from seeping into the base layer and damaging the subgrade through the pavement's micropores, thereby extending the pavement's service life. It also improves the pavement's appearance and driving comfort. Commonly used gradation types for thin-layer overlays are dense gradation or semi-open gradation, which can meet most maintenance needs. However, in special road sections, such as highways passing through residential areas or sections with poor drainage, maintenance requirements must go beyond improving anti-skid performance, extending pavement life, and improving driving comfort; they must also consider drainage and noise reduction.

[0003] For thin-layer asphalt overlays used on special road sections, in order to meet the functional requirements of drainage and noise reduction, the porosity of the mixture needs to be further increased. When the porosity of the mixture increases, the durability of the asphalt pavement will be insufficient, mainly in two aspects: one is insufficient resistance to photo-oxidative aging, and the other is that water erosion and oil stains on the road surface will cause the thin-layer asphalt mixture to loosen and fall off, thus reducing the service life of the ultra-thin overlay.

[0004] Based on this, the problem to be solved by the present invention is: how to obtain a modified asphalt with excellent aging resistance and oil resistance, which, when combined with coarse aggregate and mineral powder filler, produces an asphalt wear layer with both a large porosity and excellent durability. Summary of the Invention

[0005] The purpose of this invention is to provide a modified asphalt containing silane crosslinked polyethylene, allyl resin and 2-ethyl acrylate. By utilizing the synergistic effect between these three components, the modified asphalt exhibits excellent aging resistance and oil stain resistance.

[0006] In addition, the present invention also provides a method for preparing the modified asphalt, a wearing course made using the modified asphalt, and a construction method.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A modified asphalt, by weight, comprises 100 parts asphalt, 6-10 parts thermoplastic elastomer, 4-8 parts silane crosslinked polyethylene, 2-6 parts allyl resin, 2-6 parts 2-ethyl ethyl acrylate, and 0.1-1 parts stabilizer.

[0009] In this invention, silane-crosslinked polyethylene, allyl resin, and 2-ethyl acrylate exhibit a significant synergistic effect in terms of aging resistance and oil stain resistance. The possible mechanism is speculated to be:

[0010] In terms of aging resistance, silane-crosslinked polyethylene has a three-dimensional network crosslinked structure, which can effectively restrict molecular chain movement and reduce oxidative degradation caused by ultraviolet light and oxygen. Allyl resin forms a high crosslinking density structure through free radical polymerization under ultraviolet light curing, which reduces chain segment thermal movement and inhibits the diffusion of oxidative free radicals. Its aromatic ring structure can absorb ultraviolet light and reduce the risk of photodegradation. The long-chain alkyl side chains of 2-ethyl acrylate provide flexibility, alleviate the stress cracking caused by thermal expansion and contraction of asphalt, and its possible free radical trapping function delays oxidation. The silane crosslinked structure inhibits the oxidation of macromolecular chains, the ultraviolet absorption characteristics of allyl resin shield some light radiation, and acrylate may further delay degradation by passivating free radicals, thereby synergistically improving aging resistance.

[0011] In terms of oil resistance, the densification of the cross-linked network of silane-crosslinked polyethylene hinders the penetration of oil molecules, while the hydrophobicity of the silane groups further reduces the adsorption of oil substances; the resin skeleton of allyl resin has high chemical inertness and is resistant to solvent swelling, and the hydrophobicity of the ester groups enhances the surface's ability to resist oil adhesion; 2-ethyl acrylate introduces hydrophobic ethyl groups, reducing the polarity of the asphalt surface and reducing oil adsorption; the physical barrier of the silane cross-linked layer and the chemical inertness of the allyl resin work together to resist oil penetration, and the hydrophobic surface of the acrylate reduces the initial adhesion of oil.

[0012] Preferably, the allyl resin is diallyl phthalate or diallyl isophthalate.

[0013] Preferably, the thermoplastic elastomer is one or more combinations of SBS, SIS, and SEBS.

[0014] Preferably, the stabilizer is sulfur powder.

[0015] In addition, the present invention also discloses a method for preparing modified asphalt as described above, the specific steps of which are as follows: heating asphalt to 190°C, adding thermoplastic elastomer, silane crosslinked polyethylene, allyl resin, and 2-ethyl acrylate and stirring for 30 min, then shearing with a high-speed shearing machine for 30 min, and then adding a stabilizer and stirring for 1 h to obtain the modified asphalt.

[0016] Furthermore, the present invention also provides the use of modified bitumen as described above for preparing asphalt wearing courses.

[0017] In addition, the present invention also discloses an asphalt wear layer with drainage and noise reduction functions, which, by mass parts, contains 7-15 parts of modified asphalt as described in any one of claims 1-4, 100 parts of crushed stone, 6-10 parts of filler, 0.1-1 parts of toughening agent and 1-2 parts of elastic particles.

[0018] Preferably, the crushed stone is basalt with a size of 3-10mm; the filler is mineral powder; the toughening agent is one or more combinations of polyester fiber, polyacrylonitrile fiber, basalt fiber and lignin fiber; and the elastic particles are rubber powder with a particle size of 40 mesh.

[0019] Preferably, the basalt is porous basalt; the toughening agent is polyester fiber with a length of 6 mm, a diameter of 9-12 μm, and a density of 1.18 g / cm³. 3 Tensile strength > 500 MPa, elongation at break > 15%.

[0020] Finally, this invention discloses a construction method for the asphalt wearing course as described above, specifically including the following steps:

[0021] Step 1: Fill the cracks in the original road surface, repair the potholes, and smooth the connection at the starting and ending points and next to the structures.

[0022] Step 2: Clean the original road surface and then apply an tack coat.

[0023] Step 3: According to the composition of the wear layer as described in claim 7, mix the components together at a mixing temperature of 190-210℃;

[0024] Step 4: Spread the product from Step 3 onto the tack coat from Step 2 at a spreading temperature of 170-190℃ and a spreading thickness of 1.6-1.7cm.

[0025] Step 5: Use a double-drum roller to statically compact the road surface 2-3 times until the compacted thickness of the wearing course is 1.5±0.5cm, and the construction is completed.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] The modified asphalt disclosed in this invention utilizes the synergistic effect between three components: silane crosslinked polyethylene, allyl resin, and 2-ethyl acrylate, to give the modified asphalt excellent aging resistance and oil resistance. Furthermore, the wear layer made from this modified asphalt not only has good drainage and noise reduction functions but also has aging resistance and oil resistance. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Product Information:

[0030] Asphalt: Dongguan Taihe Asphalt Products Co., Ltd., ESSO 70# base asphalt;

[0031] Thermoplastic elastomer: SBS, YH-791H produced by Sinopec Baling Petrochemical Co., Ltd.;

[0032] Silane cross-linked polyethylene: Shanghai Xinshanghua Polymer Materials Co., Ltd., 4234 two-step silane cross-linked polyethylene insulation material;

[0033] Diallyl phthalate: DAP-A manufactured by Osaka Soda Co., Ltd.

[0034] Poly(diallyl isophthalate): Poly(diallyl isophthalate) manufactured by the German Merck Group, product number 181757;

[0035] 2-Ethylethyl Acrylate: Shanghai Jizhi Biochemical Technology Co., Ltd., Product No. E95030, Brand Acmec, Purity 99%.

[0036] Part One

[0037] The modified asphalt in the following examples and comparative examples is prepared by heating the asphalt to 190°C, adding thermoplastic elastomer, silane crosslinked polyethylene, allyl resin, and 2-ethyl acrylate, stirring for 30 minutes, then shearing with a high-speed shearing machine for 30 minutes, and finally adding a stabilizer and stirring for 1 hour to obtain the modified asphalt.

[0038] The formulations of each embodiment and comparative example are shown in Table 1.

[0039] Table 1. Modified Asphalt Formulation (parts by weight)

[0040]

[0041] In Example 4, the plastic elastomer was SIS and the allyl resin was diallyl phthalate; in Example 5, the plastic elastomer was SEBS; and in the other examples and comparative examples, the plastic elastomer was SBS and the allyl resin was diallyl isophthalate.

[0042] Part Two

[0043] The modified asphalt obtained in Example 1 and Comparative Examples 1-6 was used to prepare asphalt wearing course. The specific method was as follows: the components were mixed indoors to obtain asphalt wearing course, and rutting slabs and Marshall specimens were formed. The rutting slabs were used to test the permeability coefficient, and the Marshall specimens were used to test the runoff loss.

[0044] The formulations for each asphalt wear course are shown in Table 2.

[0045] Table 2. Asphalt Wear Course Formulation (parts by weight)

[0046] Modified asphalt Porous basalt Polyester fiber Mineral powder rubber powder Wear layer 1 8 100 0.5 8 1.2 Wear layer 2 15 100 0.1 10 1 Wear layer 3 7 100 1 6 2 Wear layer 4 8 100 0.5 8 1.2 Wear layer 5 8 100 0.5 8 1.2 Wear layer 6 8 100 0.5 8 1.2 Wear layer 7 8 100 0.5 8 1.2 Wear layer 8 8 100 0.5 8 1.2 Wear layer 9 8 100 0.5 8 1.2

[0047] Among them, the wear layers 1-3 use the modified asphalt of Example 1; the wear layers 4-9 use the modified asphalt of Comparative Examples 1-6 respectively.

[0048] Performance testing

[0049] The modified asphalt and asphalt wear course prepared in each embodiment and comparative example were subjected to the following tests;

[0050] Refer to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2011;

[0051] Modified bitumen testing:

[0052] Softening point: T 0606-2011;

[0053] Dynamic viscosity at 60℃: T 0620 -2000;

[0054] Ductility at 5℃: T 0605-2011;

[0055] Elastic recovery rate: T 0662-2000;

[0056] PAV aging test method: T 0630-2011.

[0057] Asphalt wearing course test:

[0058] Permeability coefficient: "Specifications for Field Testing of Highway Subgrade and Pavement" JTG E60-2008 T0971-2008 Test Method for Permeability Coefficient of Asphalt Pavement;

[0059] Asphalt film thickness: Appendix D of the Technical Specification for Construction of Asphalt Pavement of Highway JTG F40-2004, OGFC Mixture Proportioning Design Method;

[0060] Porosity: 《Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering》JTG E20-2011 T 0708-2011;

[0061] Kentucky spillage loss: 《Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering》JTG E20-2011 T0733-2011;

[0062] When testing Kentucky spill loss, three sets of Marshall specimens were formed from the same batch of wear-resistant layer mixture. One set was tested for Kentucky spill loss in its original state. The second set of specimens was aged in an 85°C oven for 120 hours and then tested for Kentucky spill loss again (simulating long-term aging in the field). The third set of specimens was placed in a circulating water bath of diesel and water in a 1:1 ratio at 60°C for 24 hours and then tested for Kentucky spill loss again (to simulate rainwater and road surface oil erosion).

[0063] The relevant test results are shown in Table 3-6;

[0064] Table 3-5 shows the test results of modified asphalt; Table 6 shows the test results of the wearing course.

[0065] Table 3. Test data of the original modified asphalt

[0066] Softening point / °C Dynamic viscosity at 60℃ / Pa·s Ductility at 5℃ / cm Elastic recovery rate / % Example 1 101.3 889100 46.2 99 Example 2 98.6 736940 45.1 99 Example 3 103.2 1126800 41.7 99 Example 4 100.8 798410 45.4 99 Example 5 100.2 726540 46.7 99 Comparative Example 1 99.7 824570 41.3 99 Comparative Example 2 100.5 800950 44.8 99 Comparative Example 3 100.1 625840 40.8 98 Comparative Example 4 98.2 486920 38.7 98 Comparative Example 5 97.6 536870 40.5 97 Comparative Example 6 97.9 552360 39.2 97

[0067] Table 4. Data on modified asphalt after one PAV long-term aging process

[0068] Softening point / °C Dynamic viscosity at 60℃ / Pa·s Ductility at 5℃ / cm Elastic recovery rate / % Example 1 102.5 745920 41.9 99 Example 2 99.1 689650 41.2 98 Example 3 103.3 985620 37.9 99 Example 4 101.0 726580 41.1 99 Example 5 100.6 658910 42.3 99 Comparative Example 1 101.6 562410 34.6 98 Comparative Example 2 101.7 487100 35.9 94 Comparative Example 3 101.6 456240 36.0 95 Comparative Example 4 101.7 245810 31.5 90 Comparative Example 5 99.2 445700 33.7 92 Comparative Example 6 99.7 405910 32.9 92

[0069] Table 5. Data on modified asphalt after three cycles of long-term aging with PAV

[0070] Softening point / °C Dynamic viscosity at 60℃ / Pa·s Ductility at 5℃ / cm Elastic recovery rate / % Example 1 97.2 625710 37.5 96 Example 2 96.3 581860 36.9 95 Example 3 99.5 828780 33.4 96 Example 4 95.8 603290 35.2 97 Example 5 95.4 568540 38.0 97 Comparative Example 1 91.6 196330 28.8 88 Comparative Example 2 92.5 174570 28.5 85 Comparative Example 3 92.7 169720 29.3 86 Comparative Example 4 86.9 114720 22.2 79 Comparative Example 5 85.4 126450 21.7 81 Comparative Example 6 86.6 125590 22.6 81

[0071] According to the data analysis in Table 3, the modified asphalt obtained in the embodiments of the present invention has good performance, with a softening point > 98℃, dynamic viscosity at 60℃ > 700,000 Pa·s, ductility at 5℃ > 40 cm, and elastic recovery rate > 99%.

[0072] Analysis of the data in Tables 4 and 5 shows that the modified asphalt obtained in the embodiments of the present invention maintains good performance after one and three long-term PAV aging cycles. After one long-term PAV aging cycle, its softening point is >99℃, dynamic viscosity at 60℃ is >650,000 Pa·s, ductility at 5℃ is >35 cm, and elastic recovery rate is >98%. After three long-term PAV aging cycles, its softening point is >95℃, dynamic viscosity at 60℃ is >500,000 Pa·s, ductility at 5℃ is >30 cm, and elastic recovery rate is >95%.

[0073] In contrast, the modified asphalt in Comparative Examples 1-3 lacked any one of the components of silane crosslinked polyethylene, allyl resin, and 2-ethyl acrylate. After one long-term aging in PAV, its dynamic viscosity at 60°C and ductility at 5°C decreased significantly. After three long-term aging in PAV, all performance indicators were greatly reduced.

[0074] Compared with the modified asphalt in Examples 4-6, which lacks any two of the components of silane crosslinked polyethylene, allyl resin and 2-ethyl acrylate, the degree of reduction in various properties is more obvious after both one and three long-term PAV aging cycles.

[0075] The above data demonstrates that the modified asphalt obtained in the embodiments of the present invention utilizes the synergistic effect between the three components—silane crosslinked polyethylene, allyl resin, and 2-ethyl acrylate—to achieve excellent aging resistance. These three components are indispensable in the modified asphalt of the present invention.

[0076] Table 6 Wear Layer Detection Data

[0077]

[0078] Analysis of the data in Table 6 shows that the wear layers 1-3 are wear layers made from the modified asphalt of Example 1. While having good permeability coefficient, asphalt film thickness, and porosity, they also have excellent performance in terms of scattering loss rate. Moreover, whether it is the scattering loss rate of the original mixture, the scattering loss rate of the aged wear layer mixture, or the scattering loss rate of the wear layer mixture after oil bath, they all have good performance. The original scattering loss rate is between 3.2% and 6.8%, the scattering loss after aging is between 4.3% and 8.7%, and the scattering loss rate after oil bath is between 8.2% and 9.6%. This shows that the wear layer obtained by the present invention has good drainage and noise reduction functions, as well as excellent aging resistance and oil stain resistance.

[0079] In contrast, the wearing layers 4-6 use modified asphalt compared to proportions 1-3. Although they also have good permeability coefficient, asphalt film thickness, and porosity, their scattering loss rate after aging and oil bath is poor. For example, the scattering loss rate of wearing layer 6 after aging increases to 15.8%, and the scattering loss rate after oil bath increases to 13.2%, both of which are much higher than those of wearing layers 1-3. The increase in wearing layers 7-9 is even greater, indicating that their aging resistance and oil stain resistance are insufficient.

[0080] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A modified asphalt, characterized in that, By weight, it includes 100 parts asphalt, 6-10 parts thermoplastic elastomer, 4-8 parts silane crosslinked polyethylene, 2-6 parts allyl resin, 2-6 parts 2-ethyl ethyl acrylate, and 0.3-1 parts stabilizer. The allyl resin is diallyl phthalate or diallyl isophthalate.

2. The modified asphalt according to claim 1, characterized in that, The thermoplastic elastomer is one or more combinations of SBS, SIS, and SEBS.

3. The modified asphalt according to claim 1, characterized in that, The stabilizer is sulfur powder.

4. A method for preparing modified asphalt according to any one of claims 1-3, characterized in that, The specific steps are as follows: heat the asphalt to 190°C, then add thermoplastic elastomer, silane cross-linked polyethylene, allyl resin, and 2-ethyl acrylate and stir for 30 minutes. Then, shear the asphalt using a high-speed shearing machine for 30 minutes, add a stabilizer and stir for 1 hour to obtain the final product.

5. The use of modified asphalt as described in any one of claims 1-3 to prepare asphalt wearing courses.

6. An asphalt wearing course with drainage and noise reduction functions, characterized in that, Based on mass parts, it contains 7-15 parts of modified asphalt as described in any one of claims 1-3, 100 parts of crushed stone, 6-10 parts of filler, 0.1-1 parts of toughening agent, and 1-2 parts of elastic particles.

7. The asphalt wearing course according to claim 6, characterized in that, The crushed stone is basalt with a size of 3-10mm; the filler is mineral powder; the toughening agent is one or more combinations of polyester fiber, polyacrylonitrile fiber, basalt fiber and lignin fiber; and the elastic particles are rubber powder with a particle size of 40 mesh.

8. The asphalt wearing course according to claim 7, characterized in that, The basalt is porous basalt; the toughening agent is polyester fiber with a length of 6 mm, a diameter of 9-12 μm, and a density of 1.18 g / cm³. 3 Tensile strength > 500 MPa, elongation at break > 15%.

9. A method for constructing an asphalt wearing course as described in any one of claims 6-8, characterized in that, Specifically, the following steps are included: Step 1: Fill the cracks in the original road surface, repair the potholes, and smooth the connection at the starting and ending points and next to the structures. Step 2: Clean the original road surface and then apply an tack coat. Step 3: According to the composition of the wear layer as described in claim 7, mix the components together at a mixing temperature of 190-210℃; Step 4: Spread the product from Step 3 onto the tack coat from Step 2 at a spreading temperature of 170-190℃ and a spreading thickness of 1.6-1.7cm. Step 5: Use a double-drum roller to statically compact the road surface 2-3 times until the compacted thickness of the wearing course is 1.5±0.5cm, and the construction is completed.

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