High, intermediate and low temperature performance appraisal of elastomeric and plastomeric asphalt binders and mixes

Abstract

This paper is oriented to appraise high, intermediate, and low temperature related performance of elastomeric and plastomeric binders and mixtures in order to evaluate their characteristics at various levels of environmental and loading conditions. Artificial oxidative hardening of asphalt binders and mixes was performed in the laboratory using short- and long-term aging protocols.At the binder level, the elastomers (styrene-butadiene-styrene (SBS) and rubber) and plastomer (ethylene-vinyl acetate (EVA)) materials improved high and intermediate temperature performance indices (G*/sin(delta) and G*.sin(delta), respectively). Interestingly, the aged SBS/bitumen blend had improved low-temperature cracking resistance compared to unaged counterpart. With the progress of oxidative hardening, the plastomer based binder did not show obvious change in the low-temperature cracking susceptibility compared to elastomer-modified binder. Seemingly, in the case of plastomer/bitumen blend, the propensity to low-temperature cracking is to a great extent controlled by the corresponding base bitumen. The plastomer based mixture had improved permanent deformation performance, whereas the elastomers afforded a tangible amelioration for the vulnerability to load and non-load associated cracking. The SBS based mixture showed highest low-temperature fracture energy compared to the EVA based mixture. Despite the determinantal effect of age-hardening to low and intermediate temperature-related cracking of mixes, the results confirmed that the elastomeric materials can retard the impact of aging level on the low temperature and fatigue cracking. Comparision of results was justified by the statistical analysis in order to determine the significance of bituminous material parameters on the measured properties.