Assessment of indirect tensile stress and tensile–strength ratio and creep compliance in HMA mixes with micro-silica and PMB

Abstract

This study aims to ascertain the effects of polymer-modified bitumen (PMB) and to utilize mineral filler with micro-silica (MS) on various properties of hot-mix asphalt (HMA). In this work, three specimens of an asphalt-concrete mixture were prepared. The first specimen represents a control mixture, the second specimen contains MS at rates 15, 30, and 45% by the total weight of the total aggregate as filler, and the third specimen contains MS and PMB with 4% novolac by the weight of bitumen and 15% hexamine by the weight of the novolac. The properties of designed mixes were evaluated using the indirect tensile strength test, tensile–strength ratio, and creep compliance. The test results showed an increase in the resistance of asphalt concrete to moisture damage, a reduction influence of water on asphalt concrete properties, creep compliance values indicating growing stiffness for asphalt mixture, and enhanced fatigue life. In conclusion, using 45% MS and PMB improved the properties of HMA and provided long-lasting mixtures for highway construction.

Keywords

• creep compliance
• hot-mix asphalt
• indirect tensile strength
• micro-silica
• polymer-modified bitumen