A Study of Polyethylene Terephthalate and Polypropylene Plastic to Improve Asphalt Concrete Engineering Properties

Abstract

Abstract

          This research studies the engineering properties of asphalt concrete (AC) that have been improved with recycled polyethylene terephthalate (PET) and recycled polypropylene plastic (PP) commonly found in the form of clear plastic bags. As plastic waste is one of many pollutions that contribute to today's environmental problems, researchers recognize the benefits of recycling it. This research studies AC60/70 graded asphalt concrete mixing with recycled PET and PP plastic. In different ratios by weight, various engineering property indices were tested to examine the material quality of each mix. These indices are quantified by performing the penetration test, softening point test, flash point test, and ductility test. When the initial property values are known, the researcher team then performed another test using the Marshall method for asphalt concrete testing to assess strength and functionality. The test result shows that asphalt concrete with 10% of PET has increased the stability from 2,133 lbs. to 2,824 lbs. (32.4% increased). When 10% of PP plastic was added into asphalt concrete, the stability was increased from 2,152 lbs. (without PP plastic) to 2,430 lbs., which improved by 12.92%. In conclusion, plastic recycling replacement can significantly improve engineering property of asphalt concrete.