Experimental, analytical, and analogical study of the effect of RAP extracted binder on rheology of polymer modified binder

This study attempts to scrutinise the effect of RAP on Performance Grade (PG), fatigue, and low temperature performance of polymer modified binder (PMB40). Furthermore, analytical, and analogical modelling was conducted. RAP from two sources was blended with PMB40 in proportions of 15%, 25%, and 40%. Thereafter, PG isochronal temperature sweeps, isothermal frequency sweeps and bending beam rheometer (BBR) testing was conducted. RAP sources affected both high and low temperature PG of PMB40. Viscoelastic transition temperature (TVET) increased on inclusion of RAP thereby compromising fatigue performance. Based on difference in critical temperatures (ΔTc), inclusion of RAP compromised the low temperature performance. Stiffness master curves (S(t)) illustrated an enhancement in stiffness on RAP inclusion whereas relaxation modulus master curves (E(t)) depicted a decrease in rate of decay of E(t) thereby compromising the low temperature stress relaxation potential. Both 2S2P1D and Huet models illustrated a reasonably good fit for various RAP blends.