Laboratory evaluation of cutback bitumen modified with cup lump rubber

Abstract

Abstract This research introduces a novel approach to addressing challenges in conventional asphalt used for road construction by incorporating cup lump rubber into cutback bitumen. The study investigates the viscosity and flash point of the resulting cutback bitumen to identify the optimal solvent percentage for achieving a lower mixing and compacting temperature range. Various diluent percentages were tested, ranging from 40% to 50%, across temperatures from 30°C to 70°C. Results indicate that higher diluent percentages lead to decreased viscosity in the blended bitumen. The most efficient solvent content for producing cutback bitumen-modified cup lump rubber is identified at 45% and 50% by weight of the bitumen, offering a reduced mixing and compaction temperature range. However, higher diluent content increases volatility potential and reduces the flash point. Additionally, toxicity testing reveals that lead and zinc are consistently present in cup lump rubber-infused samples, albeit below hazardous waste limits set by TCLP. The absence of lead in unmodified cutback bitumen underscores its compliance with environmental safety standards. These findings underscore the minimal environmental impact of this innovative modified bitumen formulation.