Stability properties of asphalt mixture incorporating coconut shell

Abstract

This study aims to evaluate the effect of coconut shell at varying percentages as an aggregate replacement on the stability properties of the asphalt mixture. The performance of the specimen was evaluated through stability, stiffness, density and flow tests. Five coconut shell percentages namely 0%, 10%, 20%, 30% and 40% by weight volumes were used as aggregate replacements in asphaltic concrete. The mixture design incorporating the penetration grade 60/70 bitumen was used for specimen testing. The optimum content of bitumen for asphalt mixtures was 5%. Test results showed that the stability, stiffness, density and flow of specimen increased with the increase of coconut shell content to a peak level (10%) and then decreased with further additions of coconut shell. Results also indicated that 10% coconut shell was the optimum replacement as an aggregate in the asphaltic concrete.