Use of calcium-rich wood biomass combustion ashes as filler in hot mix asphalt

In this study, calcium-rich wood biomass combustion ash (CRBA) was added as a mineral filler into an eco-friendly hot mix asphalt (HMA). Marshall mix design was used with four different CRBA contents (0%, 3.0%, 3.5%, and 4.5% (w/v %)). Pavement performance was assessed by evaluating the tensile strength, resilient modulus, fatigue strength, and performance in Lottman test. An optimum binder content of 5.5% was achieved for all modified CRBA−HMAs and the reference HMA. The CRBA filler (3.5% and 4.0%) can be used as a mineral filler to improve the Marshall stability up to 27%, compared to that of the pure mixture, and increase the fatigue response of HMA pavements by approximately three times with no harmful effects on the other evaluated properties. Additionally, the CRBA residue does not require crushing and sieving through a 0.075 mm sieve for application to a pavement field.