Evaluation of bituminous mixes in pavement structures - final report

Abstract

A summary of the research methodology, results, conclusions and recommendations of a five-year study of bituminous mixtures used in Oklahoma flexible highway pavements is presented in this terminal report. The research project was concerned with three types of surface failures that occur in flexible pavement, i.e., decreased skid resistance, rutting and transverse cracking. The investigation was primarily directed toward evaluating.and correlating the properties of asphalt-aggregate paving mixtures with these specific types of pavement distress. Siliceous (polish resistant) aggregates had no detrimental effects on stability or cohesion of surface course mixtures prepared in the laboratory, but some aggregates had high stripping tendencies. Asphalt-bound pavement layers contributed to the development of surface ruts. Higher field densities and stabilities of the mixtures should be required and more stringent material specifications are needed. To alleviate transverse cracking, low-temperature behavior of asphalt cements and mixtures should be considered in the standard mix design procedures. The stiffness modulus concept is applicable to Oklahoma materials and conditions.