Orthogonal Test Research of Asphalt Rubber Modified by Warm Asphalt Additive

Abstract

The research incorporates the technology of warm mix asphalt into asphalt rubber (forming into warm asphalt rubber) and evaluates the performance of warm asphalt rubber (WAR) binders. Crumb rubber modifiers (CRMs) of three particle sizes and one warm asphalt additive (WAA) are employed, and an orthogonal diagram is used to arrange the tests. The analysis shows that the bigger particle size and content of CRM all have positive effects on softening point, penetration index(PI), viscosity, temperature susceptibility described by viscosity, and low temperature property of WAR. But WAA content only produces positive impacts on softening point and PI; it cannot dramatically reduce the viscosity at high temperatures, and cannot improve the low temperature property of WAR. So employing WAA to reduce energy consumption for CRM-asphalt producing might be invalid.