Polymer modified asphalt and its application in anti-staining non-sticky wheel high-toughness stress absorbing layer

Abstract

The application discloses a polymer modified asphalt and application thereof in a high-toughness stress absorbing layer of anti-fouling non-sticky wheel, relates to the technical field of pavement structure layer, and the polymer modified asphalt comprises the following components in parts by weight: 70-75 parts of base asphalt, 13-15 parts of high molecular polymer, 7-9 parts of organic silicon polyurea, 4-5 parts of anti-fouling agent and 1-3 parts of antioxidant; the stress absorbing layer comprises the following components in percentage by weight: 7.0-8.5% of polymer modified asphalt, 85-90% of aggregate, 6-8% of filler and 0.1-0.3% of toughening agent. The stress absorbing layer solves the problems of the existing stress absorbing layer, such as difficult cleaning of dust and flying dust after pollution, easy damage in the use process and poor toughness.

Description

Technical Field

[0001] This invention relates to the field of road structure layer technology, specifically to a polymer-modified asphalt and its application in a high-toughness stress-absorbing layer for antifouling and non-sticking wheels. Background Technology

[0002] Most existing asphalt pavement structures in my country are based on semi-rigid base courses. Reflective cracking in semi-rigid base courses has become a major type of road damage affecting driving comfort, safety, and service life. To delay the appearance of reflective cracks, a stress-absorbing layer is usually laid before the overlay. The stress-absorbing layer not only serves as a waterproof bonding layer but also inhibits the development of reflective cracks.

[0003] Traditional stress-absorbing layer bonding materials use SBS-modified asphalt and rubberized asphalt. High SBS or rubber content gives the stress-absorbing layer high toughness, but this significantly affects the workability of hot-mix asphalt mixtures. To ensure the compaction characteristics of the stress-absorbing layer, asphalt mixtures are typically discharged at high temperatures, which accelerates asphalt mixture aging. Furthermore, the stress-absorbing layer is highly susceptible to dust and sand contamination, forming discontinuous interlayers and affecting the bonding of the structural layers. During the later paving of the surface layer, the stress-absorbing layer is easily torn off in strips by transport trucks and paver tracks, causing damage to the stress-absorbing layer.

[0004] Therefore, ensuring that the stress-absorbing layer is easily cleaned of dust and sand after contamination, is not easily damaged during use, and that its performance meets construction requirements, while possessing good shear and flexural strength, is of great guiding and practical significance for the formation of new stress-absorbing layer structures. Summary of the Invention

[0005] To address the problems of existing stress-absorbing layers being difficult to clean after contamination, easily damaged during use, and having poor toughness, this invention provides a polymer-modified asphalt and its preparation method, and applies the polymer-modified asphalt to prepare a high-toughness stress-absorbing layer for anti-fouling and non-stick wheels.

[0006] The technical problem to be solved by this invention is achieved by the following technical solution:

[0007] One object of the present invention is to provide a polymer-modified asphalt comprising the following components in parts by weight:

[0008] The composition consists of 70-75 parts base asphalt, 13-15 parts high molecular polymer, 7-9 parts organosilicon polyurea, 4-5 parts antifouling agent, and 1-3 parts antioxidant.

[0009] Furthermore, the base asphalt is one or more of 90# asphalt and 70# asphalt.

[0010] Furthermore, the polymer includes, but is not limited to, one or more of styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene rubber, TPU polyurethane, and unsaturated polyester resin. The polymer is used to improve the toughness and low-temperature performance of the base asphalt and to enhance the toughness of the stress-absorbing layer.

[0011] Further, the organosilicon polyurea is made from the following raw materials in parts by weight: 40-50 parts of α-hydro-ω-hydroxy-polydimethylsiloxane, 20-30 parts of isophorone diisocyanate, 4-6 parts of chain extender, and 30-50 parts of solvent. Preferably, the chain extender is a diamine chain extender; the solvent is a mixed solvent of tetrahydrofuran and isopropanol, with a volume ratio of tetrahydrofuran to isopropanol of 1:1.

[0012] Furthermore, the preparation method of the organosilicon polyurea includes the following steps:

[0013] S1. Under nitrogen protection, α-hydro-ω-hydroxy-polydimethylsiloxane and chain extender are mixed evenly to obtain reactant 1;

[0014] S2. Under nitrogen protection, isophorone diisocyanate and solvent are mixed evenly to obtain reactant 2;

[0015] S3. Under nitrogen protection, reactant 1 and reactant 2 are added to the reactor and reacted at room temperature. After the reaction is completed, the solvent is removed by vacuum distillation, the product is precipitated with deionized water, filtered, and dried to obtain organosilicon polyurea.

[0016] The organosilicon polyurea of ​​the present invention has both the low surface energy and hydrophobic properties of organosilicon and the good mechanical properties and high toughness of polyurea.

[0017] Furthermore, the antifouling agent is polytetrafluoroethylene (PTFE). PTFE has a low critical surface tension, giving the material a non-stick surface layer that reduces adhesion to transport vehicles and paver tracks during use.

[0018] Furthermore, the antioxidants include, but are not limited to, one or more of tris(2,4-di-tert-butylphenyl) phosphite and dialkyl thiodipropionate.

[0019] In this invention, the role of antioxidants is to prevent oxidative aging of asphalt during high-temperature processing and long-term use, and to improve the compatibility of the various components of asphalt.

[0020] The second objective of this invention is to provide a method for preparing polymer-modified asphalt, wherein the base asphalt is heated to 170-185°C, a polymer and an antifouling agent are added, and the mixture is stirred evenly. Then, an organosilicon polyurea is added and stirred evenly. Subsequently, an antioxidant is added, and the mixture is ground to obtain polymer-modified asphalt.

[0021] A third objective of this invention is to provide the application of the polymer-modified asphalt in stress-absorbing layers.

[0022] A fourth objective of this invention is to provide a stress-absorbing layer comprising the following components by weight percentage:

[0023] The composition includes 7.0-8.5% polymer-modified asphalt, 85-90% aggregate, 6-8% filler, and 0.1-0.3% toughening agent.

[0024] This invention uses polymer-modified asphalt as the binder for the stress-absorbing layer, which can reduce the surface energy of the stress-absorbing layer and improve its antifouling ability.

[0025] Furthermore, the aggregate includes fine aggregate and coarse aggregate, and is made from one or more of limestone, diabase, and basalt. Preferably, the coarse aggregate has a particle size of 3-8 mm, and the fine aggregate has a particle size of 0-3 mm.

[0026] Furthermore, the filler includes, but is not limited to, one or more of limestone powder, mineral powder, and cement.

[0027] Furthermore, the toughening agent includes, but is not limited to, one or more of inorganic fibers or organic fibers such as polyurethane fiber and basalt fiber.

[0028] Furthermore, the thickness of the stress-absorbing layer is 1.8~2.5 cm.

[0029] The beneficial effects of this invention are:

[0030] 1. The polymer-modified asphalt of the present invention contains organosilicon polyurea and polytetrafluoroethylene, which can improve the toughness of the stress absorption layer while reducing the surface energy. It can be re-bonded by the heating effect of the surface hot asphalt mixture.

[0031] 2. After the stress-absorbing layer of the present invention becomes contaminated, the dust and sand adhering to its surface can be cleaned by rinsing with water, which can avoid discontinuity of the interlayer interface due to surface contamination and improve its structural integrity.

[0032] 3. The stress-absorbing layer described in this invention has good workability and can solve the problems of high processing temperature and difficult compaction of high-toughness asphalt mixture; in addition, due to its low surface energy, the stress-absorbing layer is not easily stuck and damaged by the tires of transport vehicles and the tracks of paving machinery during use. Detailed Implementation

[0033] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0034] The following examples and comparative examples illustrate the sources of raw materials:

[0035] 90# and 70# asphalt were purchased from Shandong Qilu Petrochemical Company; SBS Huizhou Li Changrong Rubber Co., Ltd.; styrene-butadiene rubber was purchased from Jinan Xichuan Chemical Technology Co., Ltd.; TPU polyurethane was purchased from Dongguan Baojia Plastics Co., Ltd.; polytetrafluoroethylene was purchased from Dongguan Yingxiang Plastic Raw Materials Co., Ltd.; basalt was purchased from Shandong Changle Huatong Basalt Plant; limestone powder was purchased from Hubei Zhongwei Calcium Industry Co., Ltd.; mineral powder was purchased from Henan Jinrun New Materials Co., Ltd.; diabase was purchased from Shijiazhuang Yandong Mineral Products Co., Ltd.; polyurethane fiber was purchased from Shandong Yitai Engineering Materials Co., Ltd.; and basalt fiber was purchased from Taian Anfeng New Materials Technology Co., Ltd.

[0036] Example 1

[0037] Preparation of organosilicon polyurea:

[0038] S1. Under nitrogen protection, 45 parts of α-hydro-ω-hydroxy-polydimethylsiloxane and 5 parts of isophorone diamine were stirred at 3000 r / min for 30 min to obtain reactant 1.

[0039] S2. Under nitrogen protection, 25 parts of isophorone diisocyanate and 40 parts of solvent (composed of tetrahydrofuran and isopropanol in a volume ratio of 1:1) were stirred at 1000 r / min for 30 min to obtain reactant 2.

[0040] S3. Under nitrogen protection, reactant 1 and reactant 2 were added to the reactor and reacted at room temperature for 3 h. After the reaction was completed, the solvent was removed by vacuum distillation, the product was precipitated with deionized water, filtered, and dried under vacuum at 60 °C for 48 h to obtain organosilicon polyurea.

[0041] Preparation of polymer-modified bitumen:

[0042] 73 parts of 90# asphalt were heated to 150°C and set aside. The temperature of the base asphalt was raised to 180°C, and then 14 parts of polymer (SBS and styrene-butadiene rubber in a mass ratio of 1:1) and 5 parts of polytetrafluoroethylene were added. The mixture was sheared and stirred at 6000 r / min for 2 h. Then, 8 parts of the organosilicon polyurea prepared in Example 1 were added, and the mixture was sheared and stirred at 3000 r / min for 30 min. Subsequently, 2 parts of antioxidant 1010 were added, and the mixture was circulated three times in a colloid mill at 4000 r / min to obtain polymer-modified asphalt.

[0043] Preparation of stress-absorbing layer:

[0044] S1. By mass percentage, 7.5% of polymer-modified asphalt, 88.3% of aggregate (basalt) (30% fine aggregate with a particle size of 0-3 mm and 58.3% coarse aggregate with a particle size of 3-8 mm), 4% limestone powder, and 0.2% polyurethane fiber prepared in Example 1 are mixed evenly.

[0045] S2, paving (paving thickness is 2 cm), compaction;

[0046] S3. Traffic can be opened when the road surface temperature is below 50℃.

[0047] Example 2

[0048] Preparation of organosilicon polyurea:

[0049] S1. Under nitrogen protection, 40 parts of α-hydro-ω-hydroxy-polydimethylsiloxane and 4 parts of diamine chain extender (ethylenediamine and isophorone diamine in a mass ratio of 1:1) were stirred at 3000 r / min for 30 min to obtain reactant 1.

[0050] S2. Under nitrogen protection, 20 parts of isophorone diisocyanate and 30 parts of solvent (composed of tetrahydrofuran and isopropanol in a volume ratio of 1:1) were stirred at 1000 r / min for 30 min to obtain reactant 2.

[0051] S3. Under nitrogen protection, reactant 1 and reactant 2 were added to the reactor and reacted at room temperature for 2.5 h. After the reaction was completed, the solvent was removed by vacuum distillation, the product was precipitated with deionized water, filtered, and dried under vacuum at 60 °C for 48 h to obtain organosilicon polyurea.

[0052] Preparation of polymer-modified bitumen:

[0053] 73 parts of 70# asphalt were heated to 150°C and set aside. The temperature of the base asphalt was raised to 180°C, and then 13 parts of high molecular polymer (SBS and styrene-butadiene rubber in a mass ratio of 1.5:1) and 5 parts of polytetrafluoroethylene were added. The mixture was sheared and stirred at 6000 r / min for 2 h. Then, 8 parts of the organosilicon polyurea prepared in Example 2 were added, and the mixture was sheared and stirred at 3000 r / min for 30 min. Subsequently, 1 part of antioxidant 1010 was added, and the mixture was circulated three times in a colloid mill at 4000 r / min to obtain polymer-modified asphalt.

[0054] Preparation of stress-absorbing layer:

[0055] S1. By mass percentage, 7.0% of the polymer-modified asphalt prepared in Example 2, 90% of aggregate (limestone) (30% of fine aggregate with a particle size of 0-3 mm and 60% of coarse aggregate with a particle size of 3-8 mm), 2.7% of mineral powder, and 0.3% of polyurethane fiber are mixed evenly.

[0056] S2, paving (paving thickness is 2 cm), compaction;

[0057] S3. Traffic can be opened when the road surface temperature is below 50℃.

[0058] Example 3

[0059] Preparation of organosilicon polyurea:

[0060] S1. Under nitrogen protection, 50 parts of α-hydro-ω-hydroxy-polydimethylsiloxane and 6 parts of diamine chain extender (1,4-butanediamine and isophoronediamine in a mass ratio of 2:1) were stirred at 3000 r / min for 30 min to obtain reactant 1.

[0061] S2. Under nitrogen protection, 30 parts of isophorone diisocyanate and 50 parts of solvent (composed of tetrahydrofuran and isopropanol in a volume ratio of 1:1) were stirred at 1000 r / min for 30 min to obtain reactant 2.

[0062] S3. Under nitrogen protection, reactant 1 and reactant 2 were added to the reactor and reacted at room temperature for 3.5 h. After the reaction was completed, the solvent was removed by vacuum distillation, the product was precipitated with deionized water, filtered, and dried under vacuum at 60 °C for 48 h to obtain organosilicon polyurea.

[0063] Preparation of polymer-modified bitumen:

[0064] 72 parts of 90# asphalt were heated to 150°C and set aside. The temperature of the base asphalt was raised to 180°C, and then 13 parts of high molecular polymer (SBS and TPU polyurethane in a mass ratio of 1:1) and 5 parts of polytetrafluoroethylene were added. The mixture was sheared and stirred at 6000 r / min for 2 h. Then, 7 parts of the organosilicon polyurea prepared in Example 3 were added, and the mixture was sheared and stirred at 3000 r / min for 30 min. Subsequently, 3 parts of antioxidant 1010 were added, and the mixture was circulated three times in a colloid mill at 4000 r / min to obtain polymer-modified asphalt.

[0065] Preparation of stress-absorbing layer:

[0066] S1. By mass percentage, mix 8.5% polymer-modified asphalt, 85% aggregate (diabase) (32% fine aggregate with a particle size of 0-3 mm and 53% coarse aggregate with a particle size of 3-8 mm), 6.4% 42.5 silicate cement and 0.1% basalt fiber evenly.

[0067] S2, paving (paving thickness is 2 cm), compaction;

[0068] S3. Traffic can be opened when the road surface temperature is below 50℃.

[0069] Comparative Example 1

[0070] The stress-absorbing layer was prepared according to the method of Example 1, except that the polymer-modified asphalt was replaced with rubber-modified asphalt (Shandong Jingbo Petrochemical Co., Ltd., odorless asphalt).

[0071] Comparative Example 2

[0072] The stress-absorbing layer was prepared according to the method of Example 1, except that the polymer-modified asphalt was replaced with SBS-modified asphalt (Xiamen Huatai Group Co., Ltd., PG82-22).

[0073] Comparative Example 3

[0074] Polymer-modified bitumen and stress-absorbing layer were prepared according to the method of Example 1, except that α-hydro-ω-hydroxy-polydimethylsiloxane was replaced with polyoxypropylene glycol in the preparation of polyurea.

[0075] The stress-absorbing layers prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to pressure-sensitive tape holding power test, roller adhesion test, adhesive toughness and toughness test, and impact toughness test, respectively. The test results are shown in Table 1.

[0076] The pressure-sensitive tape holding power test is performed according to GB / T 4851-2002. The specific operation is as follows: (1) Spread 500 g of fine sand evenly on the stress-absorbing layer with a size of 200 mm × 200 mm × 50 mm and spread it evenly with a brush; (2) Invert the stress-absorbing layer on the vibration table and vibrate until no fine sand falls off; (3) Wash the fine sand on the stress-absorbing layer with water until no fine sand flows out of the water, and place it in a room temperature drying oven to dry; (4) Use a tape with a size of 150 mm × 100 mm to stick to the surface of the stress-absorbing layer and hold it under pressure of 3 kN for 2 min with a pressure plate; (5) Test the amount of fine sand adhered after the tape is held under pressure.

[0077] The specific steps of the adhesion performance test are as follows: (1) Place the stress absorption layer with a size of 200 mm × 200 mm × 50 mm in an oven at 135℃ and keep it warm for 1 h; (2) Place the preheated stress absorption layer in the test instrument and place A4 paper in the center of the stress absorption layer; (3) Start the instrument, run for 5 min, test the weight of the adhering material on the A4 paper and calculate the amount of adhesion.

[0078] The viscosity and toughness tests were conducted in accordance with JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering".

[0079] The impact toughness test refers to GB / T229-2007 "Metallic Materials Charpy Pendulum Impact Test Materials". The specific steps are as follows: (1) Cut the stress absorption layer into the required specifications of the sample and measure the size of the sample; (2) Place the sample in a 5℃ constant temperature chamber for 1 h, and then place the sample on the sample platform to test the impact energy.

[0080] Table 1

[0081]

[0082] As shown in Table 1, the stress-absorbing layers prepared in Examples 1-3 have high softening points, good high-temperature fluidity, and excellent antifouling, non-stick properties, anti-aging properties, elasticity, and toughness. However, Comparative Examples 1 and 2, due to the absence of polymer-modified asphalt as described in this invention, have stress-absorbing layers with inferior high-temperature fluidity, antifouling, non-stick properties, anti-aging properties, elasticity, and toughness compared to Example 1. Comparative Example 3, by replacing α-hydro-ω-hydroxy-polydimethylsiloxane with polypropylene glycol to prepare polyurea, which lacks silicon components, significantly reduces the antifouling and non-stick properties of its stress-absorbing layer.

[0083] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A polymer-modified asphalt, characterized in that, The components include the following parts by weight: The composition consists of 70-75 parts base asphalt, 13-15 parts high molecular polymer, 7-9 parts organosilicon polyurea, 4-5 parts antifouling agent, and 1-3 parts antioxidant.

2. The polymer-modified asphalt according to claim 1, characterized in that: The base asphalt is one or more of 90# asphalt and 70# asphalt.

3. The polymer-modified asphalt according to claim 1, characterized in that: The polymer is one or more of styrene-butadiene-styrene block copolymer, styrene-butadiene rubber, TPU polyurethane, and unsaturated polyester resin.

4. The polymer-modified asphalt according to claim 1, characterized in that: The organosilicon polyurea is made from the following raw materials in parts by weight: 40-50 parts of α-hydro-ω-hydroxy-polydimethylsiloxane, 20-30 parts of isophorone diisocyanate, 4-6 parts of chain extender, and 30-50 parts of solvent; Preferably, the chain extender is a diamine chain extender; Preferably, the solvent is a mixture of tetrahydrofuran and isopropanol, with a volume ratio of tetrahydrofuran to isopropanol of 1:

1. Preferably, the method for preparing the organosilicon polyurea includes the following steps: S1. Under nitrogen protection, α-hydro-ω-hydroxy-polydimethylsiloxane and chain extender are mixed evenly to obtain reactant 1; S2. Under nitrogen protection, isophorone diisocyanate and solvent are mixed evenly to obtain reactant 2; S3. Under nitrogen protection, reactant 1 and reactant 2 are added to the reactor and reacted at room temperature. After the reaction is completed, the solvent is removed by vacuum distillation, the product is precipitated with deionized water, filtered, and dried to obtain organosilicon polyurea.

5. The polymer-modified asphalt according to claim 1, characterized in that: The antifouling agent is polytetrafluoroethylene.

6. The polymer-modified bitumen according to claim 1, characterized in that: The antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite and dialkyl thiodipropionate.

7. The method for preparing polymer-modified asphalt according to any one of claims 1 to 6, characterized in that: The base asphalt is heated to 170~185℃, then a polymer and antifouling agent are added and stirred evenly. Then, organosilicon polyurea is added and stirred evenly. Finally, an antioxidant is added and ground to obtain polymer-modified asphalt.

8. The application of the polymer-modified bitumen according to any one of claims 1 to 6 in stress-absorbing layers.

9. A stress-absorbing layer, characterized in that, Includes the following components by weight percentage: The composition includes 7.0-8.5% polymer-modified asphalt, 85-90% aggregate, 6-8% filler, and 0.1-0.3% toughening agent.

10. The stress-absorbing layer according to claim 9, characterized in that: The aggregates include fine aggregates and coarse aggregates, and are made from one or more of limestone, diabase, and basalt. Preferably, the coarse aggregate has a particle size of 3-8 mm, and the fine aggregate has a particle size of 0-3 mm; Preferably, the filler is one or more of limestone powder, mineral powder, and cement; Preferably, the toughening agent is one or more of polyurethane fiber and basalt fiber.

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