Experimental study of temperature cracking susceptibility of bituminous materials with crumb rubber

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Experimental study of temperature cracking susceptibility of bituminous materials with crumb rubber

Yasmina Mahmoudi, Salvatore Mangiafico, Cédric Sauzéat, Hervé Di Benedetto, Julien Van Rompu, Jean-Philippe Faure

ABSTRACT. The influence of crumb rubber added by dry process on the resistance to the thermal cracking of bituminous mixtures was investigated. Thermal Stress Restrained Specimen Tests (TSRST) were performed on three different bituminous mixtures. The first one, used as the reference mixture, is a base course bituminous mixture containing Recycled Asphalt Pavement (RAP). The two other mixtures had the same grain distribution as the reference but 4% and 8% (on the mixture volume) of mineral coarse aggregates were replaced by crumb rubber. All the mixtures were produced with a 35/50 pen grade bitumen modified with SBS polymers and contain the same volumetric binder content and RAP content. The peak stress, corresponding to the maximum stress reached before the failure, and the corresponding cracking temperature obtained during TSRST were analysed. A good repeatability of experimental results was observed for all materials. The mixtures containing crumb rubber show lower values of peak stress compared to the reference mixture without crumb rubber. They also reached a lower temperature before failure.

KEYWORDS: Bituminous mixtures, crumb rubber, thermal cracking, RAP, dry process