Method for preparing polymer modified asphalt by one-step method

Abstract

The invention relates to a method of preparing polymer asphalt with one step to modify the asphalt by adopting the polymer as a modifying agent. In a peptizator of 80 to 160 DEG C which account for 5 to 27 percent of the total weight of the raw materials, the polymer modifying agent and 0.1 to 2 percent of stabilizer which account for 2 to 9 percent of the total weight of the raw materials are added, and then is poured into a plastic extruder where the rotating speed is 300 to 800 rotations per second to be extruded; the extruding temperature is controlled to be 130 to 210 DEG C; the extruded polymer is directly and mixingly stirred for 0.5 to 6 hours together with the asphalt which accounts for 62 to 89.9 percent of the total weight of the raw materials, then the polymer modified asphalt is gained, which is provided with good heat preservation function, good low temperature expanding performance, anti-fatigue and anti-tearing function and relatively good weatherproof function. After being mixed with the stones, the mixed materials perform good water stability and high and low temperature stability, which can effectively improve the using performance of the asphalt pavement and prolong the service life.

Description

technical field [0001] The invention relates to a method for preparing polymer-modified asphalt in one-step method using polymer as modifier to modify asphalt. Background technique [0002] The traffic characteristics of modern highways, especially high-grade highways, are large traffic volume, fast speed and heavy load, which put forward higher and higher requirements for the quality of asphalt paved on the road. Because ordinary asphalt is difficult to meet the technical requirements of asphalt for high-performance pavement, the performance improvement of ordinary asphalt is usually used at home and abroad to meet the use requirements. Adding polymers to asphalt is one of the effective ways to improve asphalt performance. Commonly used modifiers include styrene-butadiene-styrene thermoplastic elastomer (SBS) and styrene-butadiene rubber (SBR). The technical key to preparing polymer-modified asphalt is to be able to disperse the modifier uniformly in the asphalt, so as to ...

AI Technical Summary

Problems solved by technology

[0003] At present, there are three main technologies for the production of SBS modified asphalt: one is to disperse SBS directly into asphalt by high-speed shearing or colloid milling method. The modified asphalt produced by this process is easy to segregate, has poor storage stability, and the physical and chemical indicators of the product are unstable.

The second is the masterbatch method. SBS and base asphalt are mixed to make SBS modified asphalt masterbatch with a concentration greater than 20% by weight, and the masterbatch is diluted and mixed with asphalt to complete the production of modified asphalt. When granular asphalt is mixed with asphalt for dilution, the viscosity of the material will increase significantly due to the swelling of SBS, resulting in difficulty in stirring, resulting in a long time for SBS dissolution and contact solution, and easily causing the problem of SBS aging and caking. In addition, when preparing modified asphalt masterbatch , requires cooling treatment, but the mixing process of masterbatch and asphalt needs to be heated up, and a certain amount of stabilizer must be added to carry out a long-term cross-linking reaction to achieve the purpose of uniform dispersion of the modifier in the asphalt. Therefore, this process has production Defects of long cycle time and high energy consumption

The third is to chemically modify SBS in advance to improve the compatibility and compatibility between SBS and asphalt. The problem with this process is that special SBS that has been chemically modified in the factory must be used

The second is to use SBR latex and hot asphalt to mix directly through mechanical stirring, but a large amount of water vapor will be generated during the production process, which not only corrodes the equipment, but also the latex is easy to block the nozzle, which brings inconvenience to the production, and the moisture in the mixture also affects the production process. Stone Adhesion

The third is to directly mix SBR rubber powder into hot asphalt to prepare modified asphalt through a suitable mixing method. This process has problems such as easy precipitation of rubber powder and unstable product system. At the same time, rubber powder is also easy to age and affect product quality.

Although modified asphalt with good properties can be prepared, its disadvantages are high production cost and difficult reaction control

This process method and steps are cumbersome, so that the processing capacity is limited