Characterization of Combined Environmental Effects on Bituminous Paving Materials

Over the past 6.5 years, the Construction Materials Research Center (CMRC) within the Mississippi State University (MSU) department of Civil & Environmental Engineering (CEE) has been active in assessing time dependent and combined environmental effects on paving materials. A considerable amount of this work has been funded by Mississippi Department of Transportation (MDOT) and supported by industry, and a central component of this work has been a test section in Columbus, MS. This proposal, if funded, would continue the field aging work in Columbus, but would also expand CMRC’s efforts and include time dependent assessments on projects in other areas for multiple damage mechanisms. Several areas are envisioned to be monitored for time dependent environmental effects and/or usage pattern effects across MDOT’s network. The aforementioned Columbus test section itself would be one of those items. In additional Stone-Matrix Asphalt (SMA) is to be evaluated for mixing temperature and other relevant effects by way of cores or gyratory compacted specimens that would be placed on top of the full-scale Columbus parking lot test sections that have been in place since 2011. Alongside the SMA, cores or gyratory compacted specimens are also to be aged at the Columbus test section that are produced with Dense-Graded Asphalt (DGA) to widen the knowledge base of aging that has already been initiated. A fourth area of interest is monitoring pavement infiltration over time for several types of projects and pavement surfaces of interest to MDOT; infiltration monitoring is expected for Open Graded Friction Course (OGFC) with and without treatments, thin lift joints, and composite treatments such as scrub seals with a thin overlay. The final item to be assessed for time dependent and/or usage pattern effects are shoulder aggregates. This study’s objectives are as follows: (1) Improve understanding of field aging of asphalt mixtures; (2) Provide clarity on mixing temperature effects on SMA; (3) Characterize water infiltration resistance over time of several pavement surfaces, and (4) Improve MDOT shoulder aggregate practices.