An Investigation of Dynamic Modulus and Flow Number Properties of Asphalt Mixtures In Washington State

Pavement design is now moving toward more mechanistic based design methodologies for the purpose of producing long lasting and higher performance pavements in a cost-effective manner. The recent Mechanistic-Empirical pavement design guide (MEPDG) is a product under such direction and is making progresses in improving current design methods. Dynamic Modulus is proposed by the MEPDG as an important material characterization property and key input parameter which correlates material properties to field fatigue cracking and rutting performance. Washington State has strong background and has put many efforts in moving toward the M-E based design procedures. In addition, Washington State has developed comprehensive pavement management system (PMS) database which makes it possible to use local pavement performance data to calibrate design models and optimize pavement design. However, there is still one important thing missing in this implementation step, which is a comprehensive local material database. Given the limited resources (equipment and time), such database will help the designer to select material properties that are more applicable to local materials and thus develop more reasonable level III design. Therefore, the objectives of this study are to conduct dynamic modulus (E*) tests on asphalt mixtures most popularly used in the State of Washington under different climate conditions, generate material database for the implementation of MEPDG design procedure in Washington State, and provide an evaluation method for recommending potential performing mixes by correlating E* test results to field rutting performance using Washington State PMS data. Both lab prepared mixtures based on designs typically used in Western, Central, and Eastern Washington region, and field cored samples from representative field sites will be measured for dynamic modulus over a wide time-temperature domain. Results will be correlated to pavement performance, so that desirable material properties and E* values can be recommended for Washington material and climate conditions.