Melted Polyethylene Terephthalate Plastic Waste as a Binder in the Manufacture of Sand Bricks

In the province of D.I. Yogyakarta, Indonesia, plastic waste reaches 26.37% of the province's total waste. Plastic waste ranks second after food waste. Given this, managing plastic waste for essential building materials, such as sand bricks, is necessary. This study aims to determine the effect of using melted PET waste as a binding material in sand bricks on compressive strength and water absorption. The weight ratios of PET waste to sand used are: 1:2, 1:2.2, 1:2.5, 1:2.9, 1:3.3, 1:4, and 1:5. The test specimen is a 6cm x 6cm x 6cm cube. Each variation consists of 5 test specimens. The tests carried out were absorption testing and compressive strength testing. From the research obtained, the weight ratio of 1:2 to 1:4 is deemed to satisfy the criteria for quality level 3, with a minimum average compressive strength of 4 MPa. The weight ratio of 1:5 meets the requirements of quality level 4 with a minimum average compressive strength of 2.5 MPa. The weight ratio of 1:2 to 1:5 is deemed to satisfy the requisite quality level 1 bricks for walls standards, with a maximum average absorption of 25%. The density of sand bricks with various weight ratios of PET plastic waste to sand is less than that of clay brick masonry, which has a density of 1700 kg/m³.