Evaluating the performance of hot asphalt mixtures using natural materials waste

This study investigates the incorporation of four natural materials waste —Rice Husk Ash (RHA), Date Seed Ash (DSA), Palm Kernel Ash (PKA), and Saw Dust Ash (SDA)—as partial replacements (25%, 50%, 75%, and 100%) for conventional mineral filler in Hot Mix Asphalt (HMA). Mechanical and volumetric properties were evaluated using Marshall Test (MT), Indirect Tensile Strength (ITS), and Wheel Tracking Test (WTT), with moisture resistance assessed through Retained Marshall Stability (RMS). Environmental performance was analyzed via Life Cycle Assessment (LCA) using the ReCiPe 2016 method. The 75% RHA mix outperformed others across all key metrics, with increases of 5.17% in MS, 7.80% in MQ, and ITS by 31.26% dry, and 30.00% in wet. Rutting resistance improved by 41.42%, RMS reached 91.56%, and LCA showed a 7.76% reduction in total environmental impact, including 6.82% lower Climate Change impact and 5.94% reduction in Fossil Resource Scarcity. The 75% DSA mix showed strong gains in MQ by 10.22% and ITS (18.51% dry, 19.41% wet), with acceptable RMS (90.49%), but suffered a 17.16% reduction in rutting resistance, limiting its suitability for heavy traffic applications. PKA and SDA exhibited marginal or inconsistent results. The 50% PKA mix slightly improved MS by 0.65% and MQ by 1.06%, while the 25% SDA mix improved MQ by 5.26% but reduced MS by 3.21%. In summary, 75% RHA demonstrated the most balanced and sustainable performance, making it a viable alternative filler, while 75% DSA may be suited for moderate traffic where strength is prioritized over rutting resistance.