Comparative performance of DG mixes and SMA mixes with waste crumb rubber as aggregate replacement

Abstract

This research paper presents a comparative study on the performance of asphalt mixes containing waste crumb rubber as an aggregate replacement. Two different mixes namely Dense Graded (DG) and Stone Matrix Asphalt (SMA) with different ratios of waste crumb rubber WCR (0.5%, 1.0%, 1.5%, and 2.0% by weight of aggregate) were produced. The performance tests including, Marshall stability, Marshall Quotient (MQ), tensile strength, tensile strength ratio, and deformation strength in Kim test were carried out on DG and SMA asphalt mixtures. The analyses of test results show that the performance of DG-mixtures is better than SMA-mixtures in term of Marshall stability, and Marshall Quotient and lower indirect tensile strength, and Deformation Strength than SMA mixes. The moisture susceptibility and temperature susceptibility can be reduced by the inclusion of waste crumb rubber in the DG asphalt mixture. A waste crumb rubber content of 0–1.0% by weight of aggregate is recommended for the aggregate replacement of the performance of asphalt concrete mixtures similar to that investigated in this study.