QC/QA TESTING DIFFERENCES BETWEEN HOT MIX ASPHALT (HMA) AND WARM MIX ASPHALT (WMA) (FHWA-OK-13-02 2218)

Abstract

WMA represents a group of technologies which allow a reduction in temperatures at which asphalt mixtures are produced and placed on the road. ODOT Materials Division has conducted preliminary inquiries into QC/QA testing for WMA. Some respondents indicate that WMA can be tested exactly the same as hot mix asphalt (HMA) with the same results. Other data show that lab-molded and other volumetric properties are significantly different for WMA. The objectives of this study were to develop testing protocols for WMA additives and foamed WMA for mix design and QC/QA procedures. Cold feed belt samples and plant produced samples of mix were obtained and mixed with WMA additives. Mixtures were tested for lab molded voids, maximum specific gravity, moisture sensitivity and resistance to permanent deformation. The effects of reheating the WMA samples on the above mix properties were also evaluated. Recommendations are made for mix design and QC/QA procedures for WMA technologies.