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

Abstract

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 (T_VET) increased on inclusion of RAP thereby compromising fatigue performance. Based on difference in critical temperatures (ΔT_c), 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.

KEYWORDS:

• RAP
• polymer modified
• PG
• master curve
• 2S2P1D
• Huet

Acknowledgements

The authors would like to thank Industrial Research and Consultancy Centre (IRCC), IIT Bombay, for providing financial support through project no. 13IRCCSG002, to purchase dynamic shear rheometer instrument utilised in the research work. Also, the authors gratefully acknowledge the financial support of the Department of Civil Engineering, IIT Bombay, for procuring various instruments (RTFO, PAV, BBR).

Disclosure statement

No potential conflict of interest was reported by the author(s).