Waste rubber powder modified asphalt mixture and preparation method thereof

Abstract

This application relates to the field of asphalt pavement construction, specifically disclosing a waste rubber powder-modified asphalt mixture, its preparation method, and its use. The waste rubber powder-modified asphalt mixture is composed of the following raw materials in parts by weight: 4-5 parts of waste rubber powder-modified asphalt, 80-100 parts of mineral material, 20-25 parts of mineral powder, and 20-30 parts of a flame retardant component. The flame retardant component includes a compatibilizer, a filler, and a flame retardant, with the weight ratio of the compatibilizer, filler, and flame retardant being 1:3-9:16-20. The waste rubber powder-modified asphalt mixture of this application can be used in tunnel asphalt pavement construction. It has the advantages of good flame retardancy and low environmental pollution during combustion.

Description

Technical Field

[0001] The present application relates to the field of asphalt pavement construction, and more specifically, to a waste rubber powder modified asphalt mixture and a preparation method thereof. Background Art

[0002] Rubber-modified asphalt mixture is made by adding rubber powder made from waste tires as a modifier to the base asphalt, which is then subjected to a series of actions such as high temperature and shear mixing, and then mixed with other raw materials before being finally paved into an asphalt pavement.

[0003] During highway construction, adding rubber powder can improve the durability, water resistance and stone stability of asphalt pavement, especially reduce the tendency of pavement cracking, thereby increasing the service life of asphalt pavement.

[0004] Tunnel areas where accidents are frequent are prone to fires. During a fire, asphalt and rubber are ignited. The burning asphalt and rubber will release a large amount of toxic smoke, thereby polluting the surrounding environment. Summary of the Invention

[0005] In order to reduce the burning of asphalt pavement during a fire, thereby reducing pollution to the environment, the present application provides a waste rubber powder modified asphalt mixture and a preparation method thereof.

[0006] In the first aspect, the present application provides a waste rubber powder modified asphalt mixture, which adopts the following technical solution:

[0007] A waste rubber powder modified asphalt mixture is composed of the following raw materials in parts by weight: 4 to 5 parts of waste rubber powder modified asphalt, 80 to 100 parts of mineral material, 20 to 25 parts of mineral powder, and 20 to 30 parts of a flame retardant component, wherein the flame retardant component includes a compatibilizer, a filler, and a flame retardant, and the weight ratio of the compatibilizer, the filler, and the flame retardant is 1:3 to 9:16 to 20.

[0008] By adopting the above technical solution, the flame retardant performance of the asphalt pavement is improved due to the addition of the flame retardant. Since the compatibilizer is used to improve the interfacial bonding strength between the flame retardant, the filler and the waste rubber powder modified asphalt, the filler fills the gap between the waste rubber powder modified asphalt and the flame retardant, so that the stability of the flame retardant in the asphalt mixture is improved, thereby effectively improving the flame retardant performance of the asphalt pavement and effectively reducing the pollution to the surrounding environment caused by the burning of the asphalt pavement.

[0009] Preferably, the waste rubber powder modified asphalt includes base asphalt, waste rubber powder, activator and stabilizer, and the weight ratio of the base asphalt, waste rubber powder, activator and stabilizer is (80-100):(12-15):1:1.

[0010] By adopting the above technical solution, the waste rubber powder is mixed with asphalt and modified, the waste rubber powder is recycled and the stability of the asphalt is improved.

[0011] Preferably, the waste rubber powder modified asphalt is prepared by the following steps: heating the base asphalt to 165°C, adding rubber powder and stirring to mix evenly, then adding an activator and heating to 175°C, swelling for 30 minutes and stirring at 3000r / min for 20 minutes, and then adding a stabilizer and shearing for 15 minutes to obtain the waste rubber powder modified asphalt.

[0012] By adopting the above technical solution, the waste rubber powder is first activated to promote its swelling in asphalt. During the shearing process, the viscosity of the waste rubber powder increases, and the waste rubber powder degrades to produce small molecules that combine with asphalt. The addition of a stabilizer further improves the stability of the modified asphalt.

[0013] Preferably, the filler comprises flame retardant fiber, linear low-density polyethylene, diatomaceous earth and an additive, and the weight ratio of the flame retardant fiber, linear low-density polyethylene, diatomaceous earth and the additive is (20-25):(80-100):2:(3-4).

[0014] By adopting the above technical solution, during the hot mixing process, the flame retardant fiber, linear low-density polyethylene and diatomaceous earth are evenly dispersed during stirring, which on the one hand improves the flame retardant performance of the asphalt mixture, and on the other hand improves the stability of the asphalt pavement.

[0015] Preferably, the filler is prepared by the following steps: mixing and stirring the raw materials for 10 minutes, blending and extruding the mixed raw materials, and air-cooling to obtain the filler, and the obtained filler particle size is 5 mm.

[0016] By adopting the above technical solution, the raw materials are melt-blended, extruded and granulated, and then polyethylene is used as a carrier to be mixed into the asphalt mixture. During the stirring process of the asphalt mixture, the flame retardant fiber and diatomaceous earth are evenly dispersed in the asphalt mixture along with the polyethylene, thereby reducing the uneven dispersion of the flame retardant fiber and diatomaceous earth due to the adhesion of the modified asphalt. The stirring process of the asphalt mixture is accompanied by heating, and the polyethylene melts, thereby allowing the flame retardant fiber and diatomaceous earth to be combined with other components of the asphalt mixture, effectively improving the flame retardant performance and stability of the asphalt mixture.

[0017] Preferably, the auxiliary agent includes a plasticizer, an antioxidant and zinc stearate, and the weight ratio of the plasticizer, antioxidant and zinc stearate is 1:(1-2):1.

[0018] By adopting the above technical solution, the addition of antioxidants and zinc stearate can, on the one hand, reduce the oxidation of raw materials during the melting process, resulting in performance degradation, and on the other hand, play a lubricating role, facilitating the removal of the molten blend.

[0019] Preferably, the flame retardant comprises aluminum hydroxide and zinc borate, and the weight ratio of the aluminum hydroxide to the zinc borate is (3-4):1.

[0020] By adopting the above technical solution, the two flame retardants are mixed, which effectively improves the flame retardant performance of the asphalt mixture, reduces the burning of the asphalt mixture due to fire, and thus reduces pollution to the environment.

[0021] In a second aspect, the present application provides a method for preparing a waste rubber powder modified asphalt mixture, which adopts the following technical solution:

[0022] A method for preparing a waste rubber powder modified asphalt mixture comprises the following steps: heating a mineral material and asphalt separately, heating the mineral material to 160-180° C., heating the asphalt to 155-165° C., and then mixing them; then sequentially adding mineral powder, a compatibilizer, a filler, and a flame retardant; mixing evenly at 160-170° C., and distributing the material for paving.

[0023] By adopting the above technical solution, the moisture in the mineral material and asphalt is first reduced by heating, and then other raw materials are added in sequence and mixed to obtain the asphalt mixture, which is simple and convenient to operate.

[0024] In summary, this application has the following beneficial effects:

[0025] 1. Since this application uses flame retardant as the main flame retardant component, filler fills the gap, and compatibilizer improves the connection strength between flame retardant, filler and asphalt and other raw materials, the stability of asphalt pavement can be improved.

[0026] 2. In this application, the filler uses polyethylene as a carrier, and the flame retardant fiber and diatomaceous earth are introduced into the mixture along with the prepared plastic masterbatch. After the flame retardant fiber and diatomaceous earth are evenly distributed with the plastic masterbatch, the plastic masterbatch melts during the heating process, allowing the flame retardant fiber and diatomaceous earth to combine with other raw materials, thereby improving the flame retardant properties of the asphalt mixture.

[0027] 3. In this application, polyethylene, flame retardant fiber and diatomaceous earth are used as fillers. When the filler melts, the flame retardant fiber and diatomaceous earth are combined with other raw materials, and the polyethylene flows into the gaps to fill the gaps in the asphalt mixture, thereby improving the stability of the asphalt pavement. DETAILED DESCRIPTION

[0028] In this application, the matrix asphalt is 70# matrix asphalt, purchased from the market; the rubber fineness is 30 mesh, purchased from the market; the activator is a rubber activator purchased from the market; the stabilizer is a rubber heat stabilizer, purchased from the market; the mineral material is limestone AC-13 grading, purchased from the market; the mineral powder grade is S95, purchased from the market; the flame retardant fiber is aluminum silicate ceramic fiber with a length of 1-3mm, purchased from the market; the compatibilizer is maleic anhydride grafted EVA, purchased from the market; the flame retardant includes aluminum hydroxide and zinc borate, purchased from the market; the plasticizer is epoxidized soybean oil, purchased from the market; the antioxidant is Lianlong antioxidant 1010, purchased from the market.

[0029] The present application is further described in detail below with reference to the embodiments.

[0030] Preparation Example

[0031] Preparation Example 1

[0032] This preparation example discloses a filler, which is prepared by the following steps: 80 kg of linear low-density polyethylene, 20 kg of flame-retardant fiber, 2 kg of diatomaceous earth, 1 kg of plasticizer, 1 kg of antioxidant and 1 kg of zinc stearate are mixed and stirred at 50°C and 500 r / min for 10 minutes, and the mixed raw materials are fed into a twin-screw extruder, and the nine temperatures of the twin-screw extruder are set to 120°C, 130°C, 140°C, 150°C, 150°C, 155°C, 155°C, 150°C and 145°C in sequence, and the screw speed is 180 r / min. The co-extrusion is air-cooled to obtain polyethylene plastic particles, i.e., the filler, and the obtained filler particle size is 5 mm.

[0033] Preparation Example 2

[0034] This preparation example discloses a filler, which is prepared by the following steps: 90 kg of linear low-density polyethylene, 22.5 kg of flame-retardant fiber, 2 kg of diatomaceous earth, 1 kg of plasticizer, 1.5 kg of antioxidant and 1 kg of zinc stearate are mixed and stirred at 50°C and 500 r / min for 10 minutes, and the mixed raw materials are fed into a twin-screw extruder, and the nine temperatures of the twin-screw extruder are set to 120°C, 130°C, 140°C, 150°C, 150°C, 155°C, 155°C, 150°C, and 145°C in sequence, and the screw speed is 180 r / min. The co-extrusion is air-cooled to obtain polyethylene plastic particles, i.e., the filler, and the obtained filler particle size is 5 mm.

[0035] Preparation Example 3

[0036] This preparation example discloses a filler, which is prepared by the following steps: 100 kg of linear low-density polyethylene, 25 kg of flame-retardant fiber, 2 kg of diatomaceous earth, 1 kg of plasticizer, 2 kg of antioxidant and 1 kg of zinc stearate are mixed and stirred at 50°C and 500 r / min for 10 minutes, and the mixed raw materials are fed into a twin-screw extruder, and the nine temperatures of the twin-screw extruder are set to 120°C, 130°C, 140°C, 150°C, 150°C, 155°C, 155°C, 150°C and 145°C in sequence, and the screw speed is 180 r / min. The co-extrusion is air-cooled to obtain polyethylene plastic particles, i.e., the filler, and the obtained filler particle size is 5 mm.

[0037] Preparation Example 4

[0038] This preparation example discloses a filler, which is different from Preparation Example 2 in that no flame retardant fiber is added.

[0039] Preparation Example 5

[0040] This preparation example discloses a filler, which is different from Preparation Example 2 in that no diatomaceous earth is added.

[0041] Preparation Example 6

[0042] This preparation example discloses a filler, which is different from Preparation Example 2 in that: no flame retardant fiber and diatomaceous earth are added.

[0043] Preparation Example 7

[0044] This preparation example discloses a waste rubber powder modified asphalt, which is prepared by the following steps: heating 80 kg of base asphalt to 165°C, adding 12 kg of rubber powder and stirring to mix evenly, then adding 1 kg of activator and heating to 175°C, swelling for 30 minutes, stirring at 3000 r / min for 20 minutes, and then adding 1 kg of stabilizer and shearing for 15 minutes to obtain the waste rubber powder modified asphalt.

[0045] Preparation Example 8

[0046] This preparation example discloses a waste rubber powder modified asphalt, which is prepared by the following steps: heating 90 kg of base asphalt to 165°C, adding 13.5 kg of rubber powder and stirring to mix evenly, then adding 1 kg of activator and heating to 175°C, swelling for 30 minutes, stirring at 3000 r / min for 20 minutes, and then adding 1 kg of stabilizer and shearing for 15 minutes to obtain the waste rubber powder modified asphalt.

[0047] Preparation Example 9

[0048] This preparation example discloses a waste rubber powder modified asphalt, which is prepared by the following steps: heating 100 kg of base asphalt to 165°C, adding 15 kg of rubber powder and stirring to mix evenly, then adding 1 kg of activator and heating to 175°C, swelling for 30 minutes, stirring at 3000 r / min for 20 minutes, and then adding 1 kg of stabilizer and shearing for 15 minutes to obtain the waste rubber powder modified asphalt.

[0049] Example

[0050] Example 1

[0051] This embodiment discloses a waste rubber powder modified asphalt mixture, which is prepared by the following steps:

[0052] Heat the mineral material to 160-180°C, heat the asphalt prepared in Preparation Example 7 to 155-165°C, then take 80kg of the heated mineral material and 4kg of the heated asphalt and mix them, then add 20kg of mineral powder, 1kg of compatibilizer, 3kg of filler prepared in Preparation Example 1, 12kg of aluminum hydroxide and 4kg of zinc borate in turn, mix evenly at 160-170°C, and spread the material.

[0053] Example 2

[0054] This embodiment discloses a waste rubber powder modified asphalt mixture, which is prepared by the following steps:

[0055] Heat the mineral material to 160-180°C, heat the asphalt prepared in Preparation Example 8 to 155-165°C, then take 90kg of the heated mineral material and 4.5kg of the heated asphalt and mix them, then add 25kg of mineral powder, 1kg of compatibilizer, 6kg of filler prepared in Preparation Example 2, 14kg of aluminum hydroxide and 4kg of zinc borate in turn, mix evenly at 160-170°C, and spread the material.

[0056] Example 3

[0057] This embodiment discloses a waste rubber powder modified asphalt mixture, which is prepared by the following steps:

[0058] Heat the mineral material to 160-180°C, heat the asphalt prepared in Preparation Example 9 to 155-165°C, then take 100kg of the heated mineral material and 5kg of the heated asphalt and mix them, then add 25kg of mineral powder, 1kg of compatibilizer, 9kg of filler prepared in Preparation Example 3, 16kg of aluminum hydroxide and 4kg of zinc borate in turn, mix evenly at 160-170°C, and spread the material.

[0059] Example 4

[0060] This embodiment discloses a waste rubber powder modified asphalt mixture, which is different from Example 2 in that the filler is prepared in Preparation Example 4.

[0061] Example 5

[0062] This embodiment discloses a waste rubber powder modified asphalt mixture, which is different from Example 2 in that the filler is prepared in Preparation Example 5.

[0063] Example 6

[0064] This embodiment discloses a waste rubber powder modified asphalt mixture, which is different from Example 2 in that the filler is prepared in Preparation Example 6.

[0065] Example 7

[0066] This embodiment discloses a waste rubber powder modified asphalt mixture, which is different from Example 2 in that aluminum hydroxide is used instead of zinc borate.

[0067] Example 8

[0068] This embodiment discloses a waste rubber powder modified asphalt mixture, which is different from Example 2 in that zinc borate is used instead of aluminum hydroxide.

[0069] Comparative Example

[0070] Comparative Example 1

[0071] This comparative example discloses a waste rubber powder modified asphalt mixture, which is different from Example 6 in that no compatibilizer is added.

[0072] Comparative Example 2

[0073] This comparative example discloses a waste rubber powder modified asphalt mixture, which is different from Example 6 in that no filler is added.

[0074] Comparative Example 3

[0075] This comparative example discloses a waste rubber powder modified asphalt mixture, which is different from Example 6 in that no flame retardant is added.

[0076] Comparative Example 4

[0077] This comparative example discloses a waste rubber powder modified asphalt mixture, which is different from Example 6 in that no compatibilizer and filler are added.

[0078] Comparative Example 5

[0079] This comparative example discloses a waste rubber powder modified asphalt mixture, which is different from Example 6 in that no compatibilizer and flame retardant are added.

[0080] Comparative Example 6

[0081] This comparative example discloses a waste rubber powder modified asphalt mixture, which is different from Example 6 in that no filler and flame retardant are added.

[0082] Comparative Example 7

[0083] This comparative example discloses a waste rubber powder modified asphalt mixture, which is different from Example 6 in that no compatibilizer, filler and flame retardant are added.

[0084] Performance testing

[0085] The dynamic stability performance of asphalt mixture is tested according to JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" 4 Asphalt Mixture Test T0719-2011 Asphalt Mixture Rutting Test; T0709-2011 Asphalt Mixture Marshall Stability Test 4 Immersion Marshall Test Method.

[0086] GB / T 29051-2012 Flame-retardant asphalt concrete for roads - Determination of oxygen index.

[0087] Table 1 Performance test data table

[0088]

[0089]

[0090] From Example 6 and Comparative Examples 1-7 in combination with Table 1, it can be seen that the addition of the flame retardant improves the flame retardant performance of the asphalt pavement, the use of the compatibilizer improves the interfacial bonding strength between the flame retardant, the filler and the waste rubber powder modified asphalt, and the filler fills the gap between the waste rubber powder modified asphalt and the flame retardant, thereby improving the stability of the flame retardant in the asphalt mixture, thereby effectively improving the flame retardant performance of the asphalt pavement and effectively reducing the pollution to the surrounding environment caused by the burning of the asphalt pavement.

[0091] In combination with Example 2 and Examples 4-6 and Table 1, it can be seen that when polyethylene is mixed into the asphalt mixture as a carrier, the flame retardant fiber and diatomaceous earth are evenly dispersed in the asphalt mixture along with the polyethylene during the stirring process of the asphalt mixture, reducing the uneven dispersion of the flame retardant fiber and diatomaceous earth due to the adhesion of the modified asphalt. The stirring process of the asphalt mixture is accompanied by heating, and the polyethylene melts, thereby allowing the flame retardant fiber and diatomaceous earth to be combined with other components of the asphalt mixture, effectively improving the flame retardant performance and stability of the asphalt mixture.

[0092] It can be seen from Example 2, Example 7 and Example 8 and Table 1 that mixing the two flame retardants effectively improves the flame retardant properties of the asphalt mixture, reduces the burning of the asphalt mixture due to fire, and thus reduces pollution to the environment.

[0093] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A waste rubber powder modified asphalt mixture, characterized in that: The invention is composed of the following raw materials in parts by weight: 4 to 5 parts of waste rubber powder modified asphalt, 80 to 100 parts of mineral material, 20 to 25 parts of mineral powder, and 20 to 30 parts of flame retardant components, wherein the flame retardant components include a compatibilizer, a filler and a flame retardant, and the weight ratio of the compatibilizer, the filler and the flame retardant is 1:3 to 9:16 to 20; the filler includes flame retardant fiber, linear low-density polyethylene, diatomaceous earth and an additive, and the weight ratio of the flame retardant fiber, linear low-density polyethylene, diatomaceous earth and the additive is (20 to 25):(80 to 100):2:(3 to 4); the flame retardant fiber is aluminum silicate ceramic fiber with a length of 1 to 3 cm; the flame retardant includes aluminum hydroxide and zinc borate, and the weight ratio of the aluminum hydroxide and zinc borate is (3 to 4):1; the compatibilizer is maleic anhydride grafted EVA.

2. The waste rubber powder modified asphalt mixture according to claim 1, characterized in that: The waste rubber powder modified asphalt includes base asphalt, waste rubber powder, activator and stabilizer, and the weight ratio of the base asphalt, waste rubber powder, activator and stabilizer is (80-100):(12-15):1:

1.

3. The waste rubber powder modified asphalt mixture according to claim 2, characterized in that: The waste rubber powder modified asphalt is prepared by the following steps: heating the base asphalt to 165° C., adding rubber powder and stirring to mix evenly, then adding an activator and heating to 175° C., swelling for 30 minutes, stirring at 3000 r / min for 20 minutes, and then adding a stabilizer and shearing for 15 minutes to obtain the waste rubber powder modified asphalt.

4. The waste rubber powder modified asphalt mixture according to claim 3, characterized in that: The filler is prepared by the following steps: mixing and stirring various raw materials for 10 minutes, blending and extruding the mixed raw materials, and air-cooling to obtain the filler, and the obtained filler particle size is 5 mm.

5. The waste rubber powder modified asphalt mixture according to claim 4, characterized in that: The auxiliary agent comprises a plasticizer, an antioxidant and zinc stearate, wherein the weight ratio of the plasticizer, the antioxidant and the zinc stearate is 1:(1-2):1; the plasticizer is epoxidized soybean oil; and the antioxidant is antioxidant 1010.

6. The method for preparing a waste rubber powder modified asphalt mixture according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: heating the mineral material and asphalt respectively, heating the mineral material to 160-180° C., heating the asphalt to 155-165° C., and then mixing them; then sequentially adding mineral powder, compatibilizer, filler and flame retardant; mixing evenly at 160-170° C.; and distributing and paving the material.

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