Evaluation of Oil Modification Effect on Asphalt Binder Thermal Cracking and Aging Properties

摘要

Extender oils are relatively new candidates for use as asphalt modifiers to improve low temperature properties and possibly reduce the total blended binder cost. Investigating the effect of oil modification on thermal stress and strain build-up in asphalt binders during cooling cycles is critical to prevent premature thermal cracking in pavements. This study investigates the effect of oil modification on binder low temperature cracking resistance in terms of stiffness, stress relaxation rate, and fracture properties. The study compares a set of different oils commonly used and explores the relation to cracking criteria. An analytical method is used to numerically predict thermal stresses due to cooling cycles for oil-modified binders by incorporating Bending Beam Rheometer (BBR) creep stiffness values and non-linear thermal contraction rate data from glass transition test results. Furthermore, fracture properties and critical stress and strain values were measured at different temperatures using the Single Edge Notched Beam (SENB) test procedure. Overall, these results confirm that oil modifiers can potentially improve pavement cracking resistance in cold regions with the added benefit that these materials are refined waste materials that have low cost and will benefit the green missions of specifying countries.