Repurposing agricultural waste: The effectiveness of peanut husk ash in improving asphalt mixture properties

Using agricultural waste in asphalt pavements presents a promising solution for addressing environmental concerns related to waste disposal and resource conservation while enhancing pavement performance. This study aimed to scrutinize the impact of incorporating peanut husk ash (PA) as a modifier for asphalt binder on hot mix asphalt (HMA) characteristics. The base asphalt binder, which had a penetration grade of 60/80, was initially mixed with PA at various concentrations through the utilization of a high-shear mixing apparatus. The resultant modified asphalt binder was then utilized to prepare asphalt mixtures. Various performance evaluations were performed, comprising Marshall, indirect tensile fatigue (ITF), repeated load axial (RLA), and indirect tensile stiffness modulus (ITSM) tests. The incorporation of PA improved the adhesion force between the aggregates and asphalt, resulting in enhanced resistance to applied loads, reversibility, and stiffness modulus. The use of PA also increased the resistance of the mixtures to rutting and reduced their thermal susceptibility. Additionally, adding PA to asphalt mixtures in concentrations up to 8% has the effect of increasing their resistance to fatigue and avoided the occurrence of vertical cracks resulting from horizontal tensile stresses. This study concluded that a substantial enhancement in the mechanical behavior of HMA may be achieved through the incorporation of PA, as compared to a conventional mixture.