Strengthening of hot-mix asphalt mixtures reinforced by polypropylene-impregnated multifilament glass fibres and scraps

Abstract

This study presents an experimental overview of thermoplastic polymer-coated glass fibre and scrap-reinforced hot-mix asphalt (HMA) mixtures. The toughening effects of the reinforced HMA mixtures were characterised using indirect tensile and Hamburg wheel-tracking tests. The indirect tensile loading tests were used to calculate the relative indirect tensile strengths of samples and to compare their moisture susceptibilities.The fibre’s relative contributions to increasing the indirect tensile strength and the resistance to rutting are quantified by comparing the maximum indirect peak tensile stress and tensile strength ratio (TSR). The indirect tensile strength and TSR of the fibrous mixtures are nearly two times higher than those of the plain mixtures, demonstrating the lower moisture susceptibility and superior field performance of the fibrous asphalt mixture. Accelerated rutting tests using the Hamburg wheel test setup for the fibrous mixtures caused at least three times more loading passes to be required to reach the rut-depth criteria compared to the number of loading passes required for the plain mixtures.