Analysis on Moisture Susceptibility of Warm Mix Asphalt Affected by Moist Aggregate and Multiple Freeze-Thaw Cycles

摘要

To analyze the effect of moist aggregate and multiple freeze-thaw cycles on moisture susceptibility of warm mix asphalt (WMA) containing organic wax additive (Sasobit), different target moisture contents (1%, 2%, 3%) of aggregates (limestone and basalt) are simulated using the bucket-mixer heating method in lab. The moisture susceptibility of WMA that composed of 3% Sasobit modified asphalt binder (by weight of SK-90 asphalt binder) and different types of dry/moist aggregates in one/two freeze-thaw cycles are test using the modified Lottman test. The test results show the moisture susceptibility of WMA linearly decreases significantly with the increase of moisture content and freeze-thaw cycle number. The moisture susceptibility of WMA made with moist aggregate cannot meet the current specification in China. However, under identical conditions (same moisture content and freeze-thaw cycle number), the moisture susceptibility of WMA made with basalt is better than that of WMA made with limestone.