Splitting tensile strength of lightweight concrete using polypropylene coarse aggregate coated with sand

Abstract

As part of efforts to reduce plastic waste, transformation of it to one concrete component will be good for the environment. The use of plastic waste as coarse aggregate in concrete making can provide lighter concrete but with a lower strength compared to normal concrete. Accordingly, an experimental study of 42 concrete specimens using waste polypropylene coarse aggregates coated with sand was carried out. Splitting tensile tests were conducted to cylinder concrete specimens having diameter of 15 cm and depth of 30 cm respectively. Three mixtures of sand coated polypropylene coarse plastic aggregate, river sand as fine aggregate, water and Portland Composite Cement with a water-cement ratio of 0.29, 0.287 and 0.255 were conducted. The mass proportion of cement and sand are the same but the mass of plastic coarse aggregates coated with sand is specific for each mixture. Splitting tensile strength of the specimens in general shows that higher tensile strength is found for specimens having higher compressive strength. From the test results, two equations of splitting tensile strength are proposed where it is based on three different quality of lightweight concrete at the age of 7 and 28 days. Finally the splitting tensile strength for lightweight concrete using polypropylene coarse aggregate coated with sand is found to be higher than the direct tensile strength for the same lightweight concrete.