High-temperature storage-resistant high-viscosity and high-elasticity modified asphalt and preparation method thereof

Abstract

The invention discloses a method for preparation of modified asphalt with SBS and waste rubber powder as the modifier. The method adopts a physics and chemistry combined technology, uses a coupling agent to conduct chemical treatment on the modifier surface, so that a coupling effect can be generated between SBS and waste rubber powder, under a synergistic effect of EVA, extrusion molding granulation is carried out to obtain waste rubber powder / SBS / EVA blend particles. The blend particles are added into asphalt, shearing dispersion is performed, under a synergistic effect of a cross-linking agent and an antiaging agent, the modified asphalt with excellent high-and-low temperature performance, aging resistance, high elastic recovery, high 60DEG C dynamic viscosity and high temperature storage performance can be obtained. The modified asphalt product is applicable to drainage road pavements, steel bridge deck paving and old pavement reconstruction stress absorbing layers. The raw materials used by the method have wide sources, can be produced on existing SBS modified asphalt devices, and new equipment investment is unnecessary. Therefore, the modified asphalt is suitable for industrialized production and long distance transport.

Description

technical field [0001] The invention relates to road modified asphalt and a preparation method thereof, which is a high-temperature storage-resistant high-viscosity and high-elasticity modified asphalt and a preparation method thereof. Background technique [0002] By the end of the 12th Five-Year Plan, my country's road network has been basically formed, and the built expressways and urban roads will enter the maintenance period one after another. Road reconstruction means, 90% of highways in my country are semi-rigid base pavement, cracking is one of the main diseases of semi-rigid base pavement, and it is generally believed that cracking is caused by reflective cracks. Practice has proved that laying a stress-absorbing layer between the road surface and the old pavement can absorb and disperse stress and prevent cracks from reflecting to the surface. life. The stress-absorbing layer has special functions such as waterproof bonding and delaying the generation of reflectiv...

AI Technical Summary

Problems solved by technology

Ordinary modified asphalt cannot meet its index requirements, and it is necessary to develop special asphalt binders for its performance

[0003] This special asphalt binder is called high-viscosity and high-elasticity modified asphalt. There are roughly four production methods. The first is to use Japan’s high-viscosity modifier TPS for modification. The obtained modified asphalt has a high viscosity at 60°C. It is widely used in the paving of steel bridge decks due to its characteristics. However, this modifier is expensive, the price is 40,000 yuan / ton, and the addition amount is more than 12%. The comprehensive cost of modified asphalt is about 10,000 yuan / ton. The domestic market price of ordinary SBS modified asphalt is 5000-6000 yuan / ton, so it is difficult to popularize and apply

The second is to be able to replace the expensive TPS modifier. The domestic application is more of a high-content SBS modification method. Although this method can reduce costs, since the SBS addition amount must reach more than 6%, in order to adjust The viscosity should be added with not less than 3% expensive resin, the cost of this modified asphalt is still about 50% higher than that of ordinary SBS modified asphalt, so the possibility of popularization and application is small

The third is waste rubber powder modified asphalt. Compared with the above methods, although the production cost is greatly reduced, the quality control of waste rubber powder modified asphalt is relatively difficult, and most of them are modified on site. Due to the waste rubber powder modified asphalt Viscosity is relatively high, and the difficulty of construction is relatively high

CN103849153A First add waste rubber powder and cut until there are no obvious particles, then add SBS and cut until there are no obvious particles, and finally add a viscosity regulator to obtain a high-viscosity and high-elasticity modified asphalt. The gained high-viscosity and high-elasticity modified asphalt has good High-temperature stability, strong elastic recovery ability, and good low-temperature crack resistance. During the production process, the three additives must be stirred and cyclically sheared until there are no obvious particles, and then the stabilizer is added to stir and react to obtain the finished product. The production process is complicated.

[0006] (2) Add SBS shearing and grinding first, then add tackifier and compatibilizer, grind for many times first to obtain high-viscosity modified asphalt, and finally add waste rubber powder to obtain high-viscosity and high-elasticity modified asphalt, such as CN101629405, This method needs to carry out activation treatment to the used waste rubber powder, so that its application is not extensive

[0007] (3) SBS and waste rubber powder are first extruded and granulated to obtain a composite modifier, and then the composite modifier is added to the asphalt for shear dispersion to obtain a high-viscosity and high-elasticity modified asphalt, such as CN103819918A, which is achieved by this method The used waste rubber powder usually needs to be desulfurized first. On the one hand, it increases the cost. There are special restrictions, not suitable for promotion and application

[0008] (4) Grind SBS and waste rubber powder into powder at first to obtain SBS powder and rubber powder, then add the two into the extruder, granulate to obtain a solid SBS / rubber powder blend, and then blend Add the compound into the SBS modified asphalt that has been sheared and dispersed, and mix and stir to obtain a stable composite modified asphalt, such as CN103146206A. Although this method of extruding and granulating SBS and waste rubber powder can improve the quality of the modified asphalt Stability, but this extrusion is only a physical effect, the van der Waals force between the two is weak, and the modified asphalt is not suitable for long-term storage under high temperature conditions

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