Laboratory investigation of the impact of peanut husk ash as an asphalt binder modifier on physical and rheological properties

Abstract

Researchers propose using agricultural waste into asphalt pavements as a means to raise recycling rate of waste, conserve natural resources, and reduce disposal issues. This paper was set out to explore the ability of peanut husk ash (PHA) as an asphalt binder modifier. To this end, scanning electron microscope (SEM), softening point, penetration, ductility, storage stability, rotational viscosity, multiple stress creep recovery (MSCR), temperature sweep, frequency sweep, and bending beam rheometer (BBR) tests were applied. Besides, the temperature susceptibility was evaluated using the penetration index, while the fatigue parameter was applied to assess the intermediate temperature performance of asphalt binder. Moreover, the response surface methodology (RSM) was performed to assess the interactive impact of load frequency, temperature, and PHA concentrations on the rutting factor and complex modulus, besides the interaction between them. Moreover, models were proposed to fit the findings of experimental work to predict the responses. The findings manifested that asphalt binder can be modified with 8% or less of PHA without experiencing phase separation issues during high temperature storage. Furthermore, the SEM demonstrated that PHA was well dispersed in the modified asphalt. Moreover, the increment of PHA led to increase penetration index, softening point, viscosity, rutting parameter, percent recovery, and complex shear modulus, as well as reducing nonrecoverable creep compliance (Jnr), phase angle, penetration, and ductility. Although the high temperature performance was enhanced, there was a decrease in fatigue and low temperature cracking resistance. The RSM analysis revealed that the input factors significantly affected the asphalt's rutting factor, and complex modulus, and quadratic models were suggested to predict the potential for rutting.