Applicability of the DMSO (Dimethyl Sulfoxide) Aggregate Degradation Test to Determine Moisture Induced Distress in Asphalt Concrete Mixes

摘要

A laboratory investigation was conducted to evaluate the effectiveness of the dimethyl sulfoxide accelerated weathering test (DMSO test) to predict moisture-induced distress in asphalt concrete mixtures. Asphalt concrete specimens were fabricated using aggregates from three quarries. The specimens were conditioned using vacuum saturation and a series of five freeze/thaw cycles. The resilient modulus (M sub r) was obtained before and after each conditioning cycle and the Index of Retained Resilient Modulus (IRM sub r) was determined. The results indicate the DMSO test may be used to identify the potential for moisture-induced distress in asphalt concrete mixtures. However, no correlation was determined between the DMSO test results and the IRM sub r or fatigue life test results. The strain and temperature dependencies of the M sub r were determined for a dense-graded asphalt concrete mixture. It was concluded that constant stress testing may result in a misinterpretation of the IRM sub r and tests conducted within the currently accepted temperature range may result in a plus or minus 20% deviation in the IRM sub r. In an accompanying analytical program, the effect of diametral test boundary conditions on the measured value of M sub r was evaluated using two- and three-dimensional finite element models. The results indicate that the resilient modulus diametral test is adequately represented by elastic theory and an assumed plane stress condition.