Preliminary evaluation of natural rubber in bitumen emulsion for engineering application

Abstract Bitumen emulsion is essential for road construction and roof, basement, and foundation waterproofing. Bitumen particles in water are stabilized by an emulsifier. Although the formation method is simple, most bitumen emulsions are made by random and tedious experiments. Recent research has also shown the knowledge gap in bitumen emulsion industrial use, particularly formulation. To increase its performance, synthetic polymers, including SBR, SBS, and EVA, are being used for chemical modification. As the road construction tack coat, SBR improves bitumen emulsion’s thermal and rutting resistances, SBS improves thermal-induced softening resistance, and EVA improves workability during emulsification, lowering processing temperature and energy consumption. This project aims to modify bitumen emulsion with natural rubber latex (NRL). Both are viscoelastic materials, nevertheless, they operate at different phases and pH. In this work, the particle size, zeta potential and viscosity of the ingredients were first characterized before evaluating visually, the possibility of mixing both materials in the presence of a compatibiliser. The research findings suggest that the compatibility between bitumen emulsion and NRL can be achieved by using an additive. Both bitumen emulsion and NRL can be mixed without causing any destabilisation to the latex.