EVALUATION OF SBR AND PS-MODIFIED ASPHALT BINDERS AND HMA MIXTURES CONTAINING SUCH BINDERS

The present study was conducted to assess the performance of HMA modified by styrene-butadiene-rubber (SBR) and polystyrene (PS) polymers. Four different ratios; namely 1, 3, 5, and 7% of each polymer by weight of asphalt were blended with 40/50 paving grade asphalt. Both unmodified and modified asphalt binders were subjected to rheological andhomogeneity tests such as penetration, ductility, softening point, percent loss of heat and air, and temperature susceptibility. The performance tests including, Marshall stability, Marshall quotient (MQ), tensile strength, compressive strength, and flexural strength. The results show that the performance of SBR and PS modified asphalt mixtures are superior thanconventional mixtures. The moisture susceptibility and temperature susceptibility can be reduced by the implication of SBR and PS polymers inthe asphalt mixture. A polymer content of 5% for SBR and 5% for PS by weight of asphalt are recommended for the improvement of HMA performance

Keywords:

Asphalt Binder , Asphalt Mixture , Asphalt Modifiers , Polymers , Polystyrene , Styrene- Butadiene-Rubber