Performance Analysis of a Cold Asphalt Concrete Binder Course Containing High-Calcium Fly Ash Utilizing Waste Material

It has been established that cold bituminous emulsion mixtures (CBEMs) have a comparatively low initial strength in comparison to hot mix asphalt (HMA); however its superior performance with regard to carbon emissions, is a significant driver regarding its manufacture. In this study, high-calcium fly ash (HCFA) together with a fluid catalytic cracking catalyst (FCC), a rich silica-alumina waste material, have been incorporated to develop a new cold asphalt concrete binder course (CACB) bituminous emulsion mixture. HCFA was used as a substitute for traditional limestone filler while FCC was the additive used to activate the HCFA. The mixtures' performance was assessed using the indirect tensile stiffness modulus test (ITSM), assessment of resistance against permanent deformation, temperature, and water sensitivity tests. Surface morphology was tested using a scanning electron microscopy (SEM). A considerable improvement was identified by the ITSM test in addition to a substantial enhancement in rutting resistance, temperature susceptibility, and water sensitivity. It was also established that the addition of FCC to CACB mixtures was found to improve early strength as well as long-term strength, rutting resistance, temperature sensitivity, and durability.