Effect of HDPEH polymer on viscoelastic properties of SBS modified asphalt

Styrene-Butadiene-Styrene (SBS) is one of the polymer that has been used for enhancing asphalt binder properties. The present work discusses the combined effect of High Density Polyethylene Homo Polymer (HDPEHP) and SBS on conventional and rheological properties of viscosity grade 30 asphalt commonly used in India. Six blends of binders were prepared using varying percentages of SBS and HDPEHP. Various rheological tests were performed on unaged, short-term aged and long-term aged binders to evaluate the effect of both polymers. Use of both polymers increased the viscosity of polymer modified blends marginally when compared to unmodified binder. Comparison of complex modulus mastercurves indicated that at lower reduced frequencies, complex modulus values were higher for polymer modified blends in relation to unmodified binder. Higher elasticity was provided by addition of HDPEHP when compared to other blends. Analysis of relaxation modulus and creep compliance mastercurves indicated combination of SBS and HDPEHP offered higher resistance under creep load and strain under long term conditions. Thus, it can be concluded that addition of HDPEHP enhances viscoelastic properties of SBS modified binder.