19. Laboratory Evaluation of Crumb Rubber Modified Asphalt Using Over Burnt Brick Aggregate

The extensive demand for natural aggregate from the quarries results in a huge amount of dust particles which negatively impact on water resources and induce serious hazards to ground-water quality. This encourages to use locally available and waste materials in the road construction. Such material like over burnt brick aggregate (OBBA) can be used as a substitutive material for natural aggregate. The bituminous mixes prepared using OBBA yield inferior properties than the control mixes. In this study, crumb rubber powder (CR) is used to reinforce the properties of bituminous mix prepared using OBBA. The CR has incorporated through the wet process, dry process and coating method at different concentrations, i.e., 4, 6, 8, 10 and 12% by the weight of OBC. The optimum crumb rubber content (OCC) attains at 10, 8 and 10% in the wet process, dry process and coating method, respectively. It is observed that the CR-modified OBBA mix using dry process exhibits higher stability compared to the other two processes. Moreover, Indirect Tensile strength (ITS) and Tensile Strength Ratio (TSR) tests are conducted. It shows that CR-modified OBBA mixes using the dry process and wet process have met the minimum required TSR value of 80%, according to MoRT&H guidelines.