The Importance of Asphalt Mixture Air Voids on the Damage Evolution During Freeze-Thaw Cycles

摘要

In Canada, like in many other northern countries, freeze-thaw cycles are a common phenomenon. Also, it is believed that the number of freeze-thaw cycles is increasing with the influence of the climate change. Because of that, the actual methods to predict the pavement distresses may overestimate the pavement life. Environmental conditions, rate of loading and mixture properties are the most important factors that affect the complex modulus (|E*|) values. The effect of environmental freeze-thaw cycles on mechanical distresses of asphalt mixes have not yet been properly investigated. The main objective of this study was to compare the damage evolution created during freeze-thaw cycles of partially saturated samples with varying air void content. Three different percentages of air voids was used in this project. The samples were subjected to complex modulus test carried out using the Direct Tension-Compression (DTC) test on cylindrical samples. The rheological model 2S2P1D was used to simulate the behaviour of the mixes according to various states. The results indicate that the air voids content do affect the complex modulus value, and freeze-thaw cycles do decrease the value of the modulus.