Mônica Romero Santos FernandesI, *; Maria Madalena Camargo ForteII; Leni Figueiredo Mathias LeiteIII

IPetroflex Ind. e Com. S.A., Rua Marumbi 600, 25221-000 Duque de Caxias, RJ - Brazil 
IIEscola de Engenharia, UFRGS, CP 15010, 91501-970 Porto Alegre - RS, Brazil 
IIICentro de Pesquisas Leopoldo Américo Miguez de Mello - CENPES, PETROBRAS, Av. Horácio Macedo 950, 12941-915 Rio de Janeiro - RJ, Brazil

 

ABSTRACT

Currently, the most used polymer for asphalt binder modification is the thermoplastic elastomer styrene butadiene styrene (SBS) and aromatic oil is commonly added to the mixtures to improve their compatibly. This paper proposes the use of oil shale from sedimentary rock as a compatibilizer agent for polymer-modified asphalt binder (PMB). PMBs were produced by mixing a bitumen with a linear SBS copolymer (3.5% (w.w-1)) using two oil shale contents (2 and 4%) and petroleum aromatic oil to evaluate comparatively the effect of the compatibilizer agent on the SBS PMB properties. The rheological characteristics of the SBS PMBs were analyzed in a dynamic shear rheometer (DSR) and the morphology accessed by fluorescence optical microscopy. The viscoelastic behavior of the samples corroborated the results for the classical properties and varied according to the sample morphology and composition. The results indicate that the aromatic and shale oils have similar effects on the microstructure, storage stability and viscoelastic behavior of the PMBs. Thus, shale oil could be successfully used as a compatibilizer agent without loss of properties or could even replace the aromatic oil. Following the Superpave methodology it was observed that the linear- and radial-SBS PMBs and linear-SBS PMB with 2% of shale oil can be used up to 70 °C, and the linear-SBS PMBs with 4% of shale oil or 2% of aromatic oil can be used only up to 64 °C.

Keywords: asphalt binder, polymer-modified asphalt, SBS, compatibilizer agent, rheology