Representative image of workers using recycled plastic and old asphalt in a road-paving project. Image Credits: ChatGPT.
1 expected to raise the share of recycled asphalt pavement in its hot-mix asphalt from 20% to 50%. The Los Angeles experiment was therefore not simply a matter of mixing shredded bottles into ordinary asphalt. Because the company said laboratory tests suggest plastic-based roads could last eight to 13 times longer than conventional asphalt, the idea attracted attention partly.
Research on plastic-modified asphalt has found that the behaviour of the finished pavement depends on factors such as the type of plastic, the amount used and the way it is incorporated, according to Construction and Building Materials . PET is among the plastics investigated for improving properties such as stability, although researchers also note that high plastic contents can affect other characteristics of an asphalt mixture. The plastic was processed into a synthetic binder that served a different function in the road material. The environmental benefit also depended on the process temperature. Unlike traditional hot-mix asphalt paving, the technology worked at normal temperatures and avoided transporting both the old material and the replacement material. The company projected that the process would greatly reduce emissions, but these figures were estimates rather than measurements from the completed roadway. Los Angeles had also been increasing its use of reclaimed asphalt pavement, with Asphalt Plant No. This broader effort provided context for the trial, as the city was exploring ways to keep more pavement material in use rather than sending it to waste. Research published in the Journal of Traffic and Transportation Engineering similarly shows that recycled plastics can influence asphalt’s mechanical and thermal properties, but stresses that compatibility, storage stability, processing methods and long-term performance remain important considerations.
