Experimental study to investigate the engineering and durability performance of concrete using synthetic aggregates

Global plastic production is increasing significantly each year; however, the recycled percentage is still relatively low, which results in an on-going increase in the amount of waste plastic being stockpiled. There have been attempts to utilize waste plastic in different sectors to reduce its environmental impact, including its utilization as a replacement for aggregate in concrete. A novel synthetic aggregate has been developed based on the utilization of waste plastic. Its influence on the fresh, hard and durability properties of concrete when used as a replacement for either natural pumice lightweight coarse aggregate or Lytag aggregate were examined. The results indicated that the new synthetic aggregate fulfilled the strength requirements specified in ASTM C330/C330M-14 at 25% replacement level and provided both high abrasion resistance and post peak failure deformation. Furthermore, it was also noticed that using this aggregate in concrete exhibited low water absorption and chloride penetration as compared to control mixes. However, drying shrinkage increased with an increase in the replacement levels, but still providing similar values to that of normal weight concrete. It is evident from the results that the new synthetic aggregate has the potential to be utilised as a durable structural lightweight aggregate.