Creep and Recovery of Bitumen-Acacia Sap Composites

Abstract

Bitumen (B) binder creep and recovery properties have been unsatisfactory. Different synthetic binder modifies that have been used to improve its properties have led to environmental problems such as incineration and landfill. Acacia Sap (AS) a natural polymer and environmental friendly has been used successfully as a modifier. Composites of bitumen-acacia sap with different composition of sap percentage ranging from 0% to 62.5% cell sap were prepared by injection drawing process. The composites were analyzed by Dynamic Mechanical Analysis (DMA) for creep and recovery. It was found that the creep strain for all composites decreased with increase of acacia sap loading in the binder and also increased with time and temperature. This implied increased resistance to deformation of the binder. The incorporation of acacia sap improved the recovery property. In addition, modification of bitumen binder with 25% acacia sap loading gave optimum creep behavior. The Arrhenius and William Landel Ferry models were employed in the analysis.