Stable high-viscosity modified asphalt and preparation method thereof

Abstract

The invention discloses stable high-viscosity modified asphalt and a preparation method thereof. The preparation method comprises the following steps: (1) a component A: adding rare earth nitrate, phthalic acid and triethylene diamine into a mixture of waste oil and N, N-dimethylformamide according to a specific proportion, and reacting to obtain the component A containing a metal organic framework structure; preparing pretreated rubber powder: adding rare earth sulfide and raw rubber powder into waste grease, uniformly stirring, and placing in a drying oven for 6 hours to obtain the pretreated rubber powder; (2) adding the pretreated rubber powder and the modifier into the preheated matrix asphalt, performing high-speed shearing, adding the coupling agent, and performing stirring reaction; and (3) adding the component A, nano particles and phosphite ester into the modified asphalt obtained in the step (2), and slowly stirring and reacting to obtain the stable high-viscosity modified asphalt. The prepared high-viscosity modified asphalt not only has excellent viscosity and toughness and durability, but also is good in high-temperature stability and convenient to store and transport.

Description

Technical Field

[0001] The present invention belongs to the technical field of improving the performance of asphalt used in road construction and maintenance, and specifically relates to a high-viscosity modified asphalt for thin road overlays and a preparation method thereof. Background Art

[0002] High-viscosity modified asphalt for thin-layer road overlays uses modified asphalt with high viscosity, toughness and good elasticity to ensure that the asphalt binder and aggregate have a greater bonding force, achieving the effect of reducing the overlay thickness and stabilizing the overall road surface. Thin-layer overlay construction technology is mainly used for highway pavement maintenance and bridge deck paving.

[0003] The road surface layer is exposed to the air and is directly affected by the load of automobile tires. It is very easy to reduce its function due to factors such as climate, load and service life. It is advisable to carry out regular maintenance 5-10 years after the road is built. At present, the road maintenance methods mainly include micro-surfacing and thin-layer overlay. Both maintenance methods are suitable for roads with damaged surface layers but good functional layers. Micro-surfacing technology is prone to peeling, high driving noise and poor anti-cracking effect. Thin-layer overlay can avoid the technical problems existing in micro-surfacing construction and improve the durability of the maintenance layer.

[0004] The main materials for bridge deck paving construction are epoxy asphalt and thin-layer overlay. Epoxy asphalt includes epoxy resin and curing agent, which is a two-component construction. At the same time, the temperature and construction time must be strictly controlled, which brings great inconvenience to the construction. In addition, the epoxy asphalt mixture has small gaps, it is difficult to exert moisture, and the bonding effect is poor, which affects the quality of the road surface. The thin-layer overlay used in bridge deck paving can achieve multiple effects such as reducing the weight of the road surface, improving the overlay performance and facilitating construction.

[0005] The present invention simultaneously introduces a rare earth coordination polymerized metal organic framework structure and an active rare earth compound to exert the chemical activity of the system, realize multi-dimensional extension of the modifier molecular structure and strengthening of the spatial network structure, increase the system's viscosity and storage stability, and thereby achieve the effect of improving the durability of the thin layer coating. Summary of the invention

[0006] The object of the present invention is to provide a high-viscosity modified asphalt with strong viscosity and high temperature stability. The preparation method is as follows: (1) Component A: waste oil and N,N-dimethylformamide are mixed in a mass ratio of 1:1, rare earth nitrate, phthalic acid and triethylenediamine in a molar ratio of 1.0:0.7:0.3 are mixed and then mixed evenly with the mixture of waste oil and N,N-dimethylformamide in a mass ratio of 1:80. After sufficient stirring, nitric acid accounting for 5% of the mass of N,N-dimethylformamide is added, poured into a reactor, and reacted at 150°C for 24 hours to obtain component A containing a metal organic framework structure; (2) Preparation of pretreated rubber powder: add 0.1-3 parts of rare earth metal sulfide to 5-15 parts of waste oil and grease, stir evenly, add 100 parts of rubber powder, mix evenly, and place in an oven at 110-150°C for 6 hours to obtain pretreated rubber powder; (3) Preheat 100 parts of base asphalt to 160-210°C, add 5-20 parts of pretreated rubber powder and 4-10 parts of modifier, high-speed shear at 170-180°C for 10-60 minutes, add 0.15-10 parts of coupling agent, stir and react at 190-210°C for 1-2 hours; (4) Add 0.1-2 parts of component A, 0.1-2 parts of nanoparticles and 0.01-0.05 parts of phosphite to the modified asphalt of step (3), and slowly stir and react at 170-180° C. for 1-2 hours to obtain a highly viscous modified asphalt.

[0007] Waste grease is a mixture of waste motor oil and waste vegetable oil, with the ratio of motor oil to vegetable oil ranging from 4:1 to 1:1.

[0008] The rare earth metals include one of lanthanum, cerium, praseodymium, neodymium, samarium, dysprosium, terbium, holmium, and gadolinium.

[0009] The rubber powder is ordinary tire raw rubber powder with a particle size of 20-60 mesh.

[0010] The coupling agent is a silane coupling agent, specifically one or more of aminosilane, epoxysilane, methacryloxysilane, vinylsilane, phenylsilane and sulfur-containing silane.

[0011] The modifier is two or more of polyetherimide, succinic acid, polylactic acid, stearic acid and SBS.

[0012] The nanoparticles are one of calcium carbonate, calcium oxide and calcium sulfate.

[0013] The phosphite is one of trimethyl phosphite, triethyl phosphite and triphenyl phosphite.

[0014] Compared with the prior art, the present invention has the following innovations: rare earth coordinated polymerized metal organic framework structure, strengthening the multi-dimensional extension of the molecular structure and the spatial network structure of the asphalt composite modifier, and increasing the viscosity and toughness of the system; making full use of the reaction activity of rare earths, chemically cross-linking reaction with the rubber powder modified asphalt component, and synergistically improving the viscosity, toughness and storage stability of the system with the metal organic framework structure, modifier, etc. DETAILED DESCRIPTION

[0015] The following is a further description of the process and performance of the high-viscosity modified asphalt preparation method provided by the present invention in conjunction with specific examples, but the present invention is not limited to the following examples. Example 1

[0016] (1) Waste oil and N,N-dimethylformamide were mixed in a mass ratio of 1:1, cerium nitrate, phthalic acid and triethylenediamine in a molar ratio of 1.0:0.7:0.3 were mixed with the mixture of waste oil and N,N-dimethylformamide in a mass ratio of 1:80, and after being fully stirred, nitric acid accounting for 5% of the mass of N,N-dimethylformamide was added, poured into a reactor, and stirred at 150°C for 24 hours to obtain component A; (2) Add 1 part of samarium sulfide to 10 parts of waste grease (the mass ratio of engine oil to vegetable oil is 3:1) and stir evenly, then add 100 parts of 30-mesh rubber powder and mix evenly, place in an oven at 150°C for 6 hours to obtain pretreated rubber powder; (3) Preheat 100 g of base asphalt to 190 °C, add 15 g of pretreated rubber powder and 7 g of a modifier prepared by mixing SBS and polyetherimide in a mass ratio of 5:1, and high-speed shear at 170-180 °C for 60 min. Add 2 g of γ-aminopropyltriethoxysilane and stir at 190 °C for 2 h. Add 1 g of component A, 2 g of nano-calcium carbonate and 0.02 g of trimethyl phosphite and slowly stir at 170-180 °C for 2 h to obtain a high-viscosity modified asphalt. Example 2

[0017] (1) Waste oil and N,N-dimethylformamide were mixed in a mass ratio of 1:1, cerium nitrate, phthalic acid and triethylenediamine in a molar ratio of 1.0:0.7:0.3 were mixed with the mixture of waste oil and N,N-dimethylformamide in a mass ratio of 1:80, and after being fully stirred, nitric acid accounting for 5% of the mass of N,N-dimethylformamide was added, poured into a reactor, and stirred at 150°C for 24 hours to obtain component A; (2) Add 1 part of samarium sulfide to 12 parts of waste grease (the mass ratio of engine oil to vegetable oil is 3:1) and stir evenly, then add 100 parts of 40-mesh rubber powder and mix evenly, place in an oven at 150°C for 6 hours to obtain pretreated rubber powder; (3) Preheat 100 g of base asphalt to 190 °C, add 10 g of pretreated rubber powder and 7 g of a modifier prepared by mixing SBS and polyetherimide in a mass ratio of 5:1, and high-speed shear at 170-180 °C for 60 min. Add 2 g of γ-methacryloxypropyltrimethoxysilane and stir at 190 °C for 2 h. Add 2 g of component A, 2 g of nano-calcium carbonate and 0.02 g of trimethyl phosphite and slowly stir at 170-180 °C for 2 h to obtain a high-viscosity modified asphalt. Comparative Example

[0018] 100g of base asphalt was preheated to 190℃, 10g of raw rubber powder (30 mesh) and 7g of SBS were added, high-speed shearing was performed at 170-180℃ for 60min, and stirring reaction was performed at 190℃ for 2h to obtain high-viscosity modified asphalt.

[0019] Technical indicators of high viscosity modified asphalt

Claims

1. A method for preparing a stable high-viscosity modified asphalt, characterized in that: The specific steps of the preparation method are: (1) Component A: waste oil and N,N-dimethylformamide are mixed in a mass ratio of 1:1, rare earth nitrate, phthalic acid and triethylenediamine in a molar ratio of 1.0:0.7:0.3 are mixed and then mixed evenly with the mixture of waste oil and N,N-dimethylformamide in a mass ratio of 1:

80. After sufficient stirring, nitric acid accounting for 5% of the mass of N,N-dimethylformamide is added, poured into a reactor, and reacted at 150°C for 24 hours to obtain component A containing a metal organic framework structure; (2) Preparation of pretreated rubber powder: add 0.1-3 parts of rare earth metal sulfide to 5-15 parts of waste oil and grease, stir evenly, add 100 parts of rubber powder, mix evenly, and place in an oven at 110-150°C for 6 hours to obtain pretreated rubber powder; (3) Preheat 100 parts of base asphalt to 160-210°C, add 5-20 parts of pretreated rubber powder and 4-10 parts of modifier, high-speed shear at 170-180°C for 10-60 minutes, add 0.15-10 parts of coupling agent, stir and react at 190-210°C for 1-2 hours; (4) Add 0.1-2 parts of component A, 0.1-2 parts of nanoparticles and 0.01-0.05 parts of phosphite to the modified asphalt of step (3), and slowly stir and react at 170-180° C. for 1-2 hours to obtain a highly viscous modified asphalt.

2. The preparation method according to claim 1, characterized in that: Waste grease is a mixture of waste motor oil and waste vegetable oil, with the ratio of motor oil to vegetable oil ranging from 4:1 to 1:

1.

3. The preparation method according to claim 1, characterized in that: The rare earth metals include one of lanthanum, cerium, praseodymium, neodymium, samarium, dysprosium, terbium, holmium, and gadolinium.

4. The preparation method according to claim 1, characterized in that: The rubber powder is ordinary tire raw rubber powder with a particle size of 20-60 mesh.

5. The preparation method according to claim 1, characterized in that: The coupling agent is a silane coupling agent, specifically one or more of aminosilane, epoxysilane, methacryloxysilane, vinylsilane, phenylsilane and sulfur-containing silane.

6. The preparation method according to claim 1, characterized in that: The modifier is two or more of polyetherimide, succinic acid, polylactic acid, stearic acid and SBS.

7. The preparation method according to claim 1, characterized in that: The nanoparticles are one of calcium carbonate, calcium oxide and calcium sulfate.

8. The preparation method according to claim 1, characterized in that: The phosphite is one of trimethyl phosphite, triethyl phosphite and triphenyl phosphite.

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