An Investigation of Concrete Properties with Polypropylene (Pp) As An Partial Replacement of Coarse Aggregate

Abstract

Plastic is one of the most used materials in today‟s world. Because of its non-biodegradable characteristics, it is obligatory to recycle the plastic in order to save the nature from its adverse effect. Plastic can be recycled by using it for construction purposes. This study aims at investigating the fresh and hardened properties of concrete while adopting polypropylene (PP) as coarse aggregate in concrete. Three concrete types were prepared using crushed stones and brick chips as coarse aggregate and in three cases these were partially, 10%, 20% and 30% by volume, replaced with PP. Two water cement ratio, i.e. 0.45 and 0.55, were used in the concrete mix design. Compressive strength (for 7 days, 28 days and 90 days) and tensile strength(for 28 days) tests were conducted to find out the feasibility of the plastic concrete and propose a replacement ratio for PP to be used in structural concrete. Compare to the concrete with no PP, 10 % PP replaced concrete (PRC) showed a significant increase in both compressive and tensile strengths for stone and brick chips replacement. However, with 20% and 30% PRC an opposite trend was observed. For 10% PRC, 28 days compressive strength increased as high as 69% and 10%; whereas, tensile strength improved as much as 39% and 48% for stone and brick replaced concrete respectively. Reduction in concrete density was moderate for PRC. The density decreases with the increasing percentage of plastic replacement because of the lighter weight of plastic. Through this study, it is revealed that PP can be used as a partial replacement of crushed stones and brick chips as coarse aggregate and with PRC it is possible to achieve higher strength and reduction in density.