The vast majority of roads in China use asphalt as a material, but asphalt is an easily aging substance. Asphalt pavement is exposed to sunlight for a long time and is subjected to different weather conditions such as rain and air, causing physical and chemical reactions between asphalt and mineral materials. Asphalt molecules undergo oxidation and polymerization, transforming low molecular weight compounds into higher molecular weight compounds, leading to deterioration of road performance. As a result, the chemical properties of asphalt change, with reduced penetration, reduced ductility, increased softening point, increased absolute viscosity, and reduced brittleness. If the asphalt pavement is not renovated or repaired, it is highly likely to cause car accidents and irreversible losses. How to choose equipment for crushing and screening asphalt pavement milling and planing materials?
Regarding the reuse of old asphalt
The mixture of old asphalt pavement that has been excavated, recycled, crushed, screened, and then re mixed with rejuvenators, new asphalt materials, new aggregates, etc. in a certain proportion is called recycled asphalt mixture. Using recycled asphalt mixture for road paving not only saves a large amount of raw materials such as asphalt and sand, but also saves project investment funds, reduces resource waste, and avoids environmental damage caused by waste materials.
Double axis roller crushing equipment
Nowadays, most of the equipment on the market uses double roll crushing equipment to crush asphalt pavement. Double axis roll crushing equipment adopts a staggered method to crush recycled materials, which has the characteristics of not damaging the original gradation of RAP. The gap between the crushing rollers can be adjusted to ensure the buffering effect of the crusher. The milling and screening equipment for asphalt pavement recycling has the characteristics of high pass rate, less likely to get stuck, low noise, and low failure rate.
Construction method
The technology of asphalt pavement recycling can be divided into four construction methods: factory mixed hot recycling, on-site hot recycling, factory mixed cold recycling, and on-site cold recycling. Factory mixed hot recycling refers to the process of transporting milling waste materials back to the asphalt mixing plant during the cold milling and hot paving construction of old road surfaces. The waste materials are mixed and stirred with new asphalt materials, rejuvenators, and new aggregates in a certain proportion in a hot state to form a qualified asphalt mixture. In situ thermal regeneration mainly refers to the construction method of heating the surface layer of the old road surface to the required depth, loosening the old road surface, adding reducing or regenerating agents, and re paving it into shape.
Factory mixed cold recycling is a construction method that uses emulsified asphalt or low viscosity asphalt in a hot state to mix with waste asphalt materials and new aggregates at room temperature to form a recycled mixture. After being transported to the construction site, it is spread and compacted to form a road surface.
On site cold recycling refers to the construction method of cold crushing and loosening old road surfaces, adding emulsified asphalt and other additives, mixing, paving, and compacting to form road surfaces.
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