Moisture susceptibility evaluation of asphalt mixture with account of horizontal loads: A novel test method

Pavements at intersections are more susceptible to moisture-induced damages (potholes, etc.) than usual road sections, especially in high-temperature and rainy regions. Horizontal loads aggravate such damages at intersections brought by vehicles' frequent starting and braking. However, rare consideration of the horizontal load in present test methods fails to precisely evaluate the moisture susceptibility of asphalt mixtures, which may result in an overestimation of moisture susceptibility. Therefore, this study proposes a novel test method considering the horizontal load, which combines the freeze-thaw conditioning and oblique shear test with test parameters determined via laboratory tests. The specimen preparation and test procedure are outlined, and the shear strength ratio is used to characterize the moisture susceptibility of asphalt mixtures under freeze-thaw cycles and horizontal loads. The test method is sensitive to different asphalt mixture types and designation factors (air voids), and the prefabricated notch recommended in this study makes the test repeatable because of its low variability. Finally, the finite element method is utilized, proving that the proposed test's loading pattern reflects the actual pavement's mechanical response and that their mechanical indicators are consistent. [Display omitted] •A novel method is investigated for evaluating the moisture susceptibility of asphalt mixture considering horizontal load.•A test procedure combining the oblique shear test and the water bath treatment was proposed.•The prefabricated notch was recommended due to its capacity to reduce variability.•The novel method shows favorable sensitivity and is feasible to identify qualified materials for engineering applications.