Effect of styrene-butadiene on rheological properties of asphalt emulsion

Abstract

One of the main issues with cold mix asphalt (CMA) mixtures is having poor abrasion resistance with low cohesion, longer curing time and low elasticity. SBR is used to improve the rheological properties of the asphalt emulsion. This paper evaluates the effect of using different percentages of SBR in unaged slow-setting emulsion (SS-1K) in CMA. These modified emulsions were blended at various percentages, i.e. 2%, 4%, 6%, 8% and 10% of the weight of asphalt emulsion. The investigation focused on the rheological aspect which correlates the properties of unaged modified asphalt emulsion with its performance. Dynamic Shear Rheometer test (DSR) was used to measure the parameters of complex shear modulus, G* and phase angle, δ of the asphalt samples. Based on the results, it shows that by adding SBR in the asphalt emulsion improve the rutting resistance. From the isochronal curve, the complex modulus, G* of the modified emulsions was found higher than the unmodified emulsion. The modified emulsions show signs of improvement in binder properties in terms of elastic deformation and viscosity reduction. Therefore, it can be concluded that the SBR could improve the performance of the asphalt emulsion used in CMA.