An exploration into the utilization of recycled waste glass as a surrogate powder to crushed stone dust in asphalt pavement construction

Abstract

Growing attempts aimed at decreasing the consumption of huge amounts of natural materials as means of saving global limited financial resources have led to investigations into the feasibility of utilizing surrogate and sustainable materials in asphalt pavements. Enormous amounts of discarded glass and its derivatives are ending up in global landfills. This massive increase in such stockpiles is now outpacing the world’s ability to degrade such post-consumer glass. It is this issue that provoked this investigation into the potential incorporation of such abundant waste glass as an alternative powder in the production of asphaltic concrete, hoping that such utilizations will not only decrease global dependency on quarry-based scarce resources, but will also serve to facilitate effective solid waste management. As a means of validating this conjecture, we conducted laboratory tests on asphalt mortars that included recycled waste glass (RWG) and reference crushed stone dust (CSD) at three filler bitumen ratios (0.1, 0.2 and 0.4). We next carried out widespread performance tests on asphalt mixtures with RWG and control asphalt mixtures with CSD. We used both conventional (penetration, softening point, penetration index, and ductility) and rheological (rotational viscosity and dynamic shear rheometer) tests to evaluate the properties of the RWG and CSD mastics. The mechanical properties of asphalt RWG and CSD mixtures were examined by using the Marshall test, indirect tensile stiffness modulus, indirect tensile fatigue test, and dynamic creep test. We also inspected the morphological impact of RWG on the bitumen phase by analyzing the images captured with a Scanning Electron Microscope. Our findings indicate that green sustainable roads augmented by RWG comply with the relevant specifications, and that RWG utilizations provide significant improvements in the thermal susceptibility and fatigue performance of these roads, thus confirming the feasibility of RWG under certain practical applications.