Resilient modulus of hot-mix asphalt gap graded with waste rubber tire additives

The protection of pavement structures on surface layer is achieved by using non-structural mixed layers, e.g., hot rolled sheet (HRS). The aim is to place between layers of pavement in order to increase the load capacity and act as an impermeable layer. HRS is expected to create high flexibility and durability coupled with the specification of gap graded aggregates to create increased inter aggregate cavities, and thereby increase the quantity of absorption of asphalt. In the present study, the improvement in the quality and performance of HRS was achieved using Refined Buton Asphalt (RBA) and the addition of crumb rubber (CR). Testing of CR involved replacing fine aggregates based on volume considerations and adding RBA to the optimum asphalt levels. Marshall standard tests and Marshall immersion tests were performed to determine the Marshall stability ratio (MSR). A universal material testing apparatus (UMATTA) tool was used to perform an indirect tensile strength (ITS) test. The results indicate that the value of resilient modulus (Mr) decreases with an increase in the temperature. The addition of CR in the modified HRS-WC mixture decreases the resilient modulus (Mr) value when compared with that of the mixture without the addition of CR (0%) with a decrease of only 6.95% at 25 °C.The protection of pavement structures on surface layer is achieved by using non-structural mixed layers, e.g., hot rolled sheet (HRS). The aim is to place between layers of pavement in order to increase the load capacity and act as an impermeable layer. HRS is expected to create high flexibility and durability coupled with the specification of gap graded aggregates to create increased inter aggregate cavities, and thereby increase the quantity of absorption of asphalt. In the present study, the improvement in the quality and performance of HRS was achieved using Refined Buton Asphalt (RBA) and the addition of crumb rubber (CR). Testing of CR involved replacing fine aggregates based on volume considerations and adding RBA to the optimum asphalt levels. Marshall standard tests and Marshall immersion tests were performed to determine the Marshall stability ratio (MSR). A universal material testing apparatus (UMATTA) tool was used to perform an indirect tensile strength (ITS) test. The results indicate that t...