Early Assessment Study of The Waste Plastics – Waste Fly Ash Composite as Non-Cement Paving

Abstract The production of plastic waste, such as Polypropylene (PP), polyethene terephthalate (PET), High-Density Polyethene (HDPE), or unclassified plastics, is difficult to degrade and pollutes the environment. On the other hand, fly ash production in Indonesia, as waste from coal combustion, will reach 16.2 million tons in 2027. This research is urgent to solve the environmental problem by combining plastics with fly ash to form a composite as a non-cement paving (mixed). The specimens were divided into four groups based on volume fractions of the fly ash: the 10 % group, the 20 % group, the 30 % group, and the group without fly ash (as a control group). Plastics and fly ash were mixed and heated at around 250 degrees Celsius. The mechanical testing followed the compression test standard SNI 03-0691-1996 with five samples for each volume fraction group. The results were statistically analyzed using ANOVA with Tukey’s post-hoc test, and paired t-tests were conducted to compare the effect of the amount of fly ash; a p-value of 0.05 or lower indicated statistical significance. The mechanical compression test demonstrated that the strength of the PET – fly ash composite was not better than other plastic – fly ash composite, the strength of the HDPE – fly ash composite was not influenced by volume fraction, the strength of the PP – fly ash composite increased because of addition of fly ash, and the strength of the unclassified plastic – fly ash composite was not influenced or seems drop because of addition of fly ash.