Preparation method of modified rubber powder, rubber powder modified asphalt and mixture and preparation method thereof

Abstract

The invention relates to a preparation method of modified rubber powder, which comprises the following steps: blending polymer and asphalt to prepare modified asphalt having uniform and stable performance, uniformly coating the modified asphalt on the surface of rubber powder, enabling the rubber powder to be thoroughly pre-swollen, and separating rubber powder particles with separant to keep therubber powder in a powder form and consequently achieve the purpose of enhancing dispersion, thus obtaining the novel modified rubber powder, wherein the separant can lower the processing difficulty during the mixture of the rubber powder and the asphalt while enhancing dispersion and keeping the rubber powder in the powder form. The invention also includes rubber powder modified asphalt using the modified rubber powder and a preparation method thereof, and a modified asphalt mixture and a preparation method thereof. When being used in the field of modified asphalt, the modified rubber powdercan be simultaneously used for improving the processing technique based on the wet method and the product performance based on the dry method.

Description

technical field [0001] The invention relates to the preparation of a high-performance high-dispersion modified rubber powder, which is used to improve the performance of road asphalt. Background technique [0002] With the rapid development of the transportation industry, a large number of waste tires are produced, and the recycling of waste tires has become a worldwide problem. In the rubber materials used in tires, the polymer chains have been chemically cross-linked, and there are high proportions of fillers (mainly carbon black), softening oil and other substances, which have many restrictions on recycling, and waste tires are used to produce Rubber powder is one of the most reasonable and effective ways recognized by people. Asphalt is a road paving material widely used in the world. With the rapid development of road construction, people have higher and higher requirements for asphalt concrete. The technology of waste rubber powder modified asphalt came into being un...

AI Technical Summary

Problems solved by technology

The current wet waste rubber powder modified asphalt technology is mostly a high-temperature wet process, that is, it is made by long-term high-speed stirring at a relatively high temperature (200°C); there are also methods of mixing asphalt with waste rubber powder, SBS, PE, etc. Polymer materials are produced at temperatures above 180°C by colloid mills and other high-shear blending and dispersing equipment, such as CN 100445333C, CN 1170733A, and CN101275027A, but the above-mentioned methods have high modification temperatures and serious secondary pollution And the shortcomings of high energy consumption, poor performance, and large amount of processed asphalt have caused certain restrictions on the development of wet methods.

Since the segregation problem of rubber modified asphalt has not been well solved, the rubber modified asphalt under the wet process must be processed and used on site and cannot be transported over long distances, which has brought many challenges to the processing and production of rubber modified asphalt. Difficulties also limit the development of wet modification

Although the dry method is convenient, the performance of the dry method is far lower than that of the wet method due to insufficient swelling time of the rubber powder and uneven dispersion.

Shanghai Jiaotong University and others have developed a dry-process modified asphalt masterbatch (CN 101885867A) to improve the performance of asphalt mixtures, but because it needs to be pelletized by twin-screw extrusion at high temperatures, the energy consumption and cost of the product are increased, and other Like similar masterbatch products, its product has a cylindrical particle shape of 4mm, which cannot solve the swelling and rapid dispersion of rubber powder well, so it cannot fundamentally improve the performance of asphalt mixture in dry process

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