Investigation on moisture damage resistance of asphalt pavement in salt and acid erosion environments based on Multi-scale analysis

The existing research on the moisture damage resistance of asphalt pavement in salt and acid erosion environments is mostly indirect tensile tests based on asphalt mixture scale. There is little comprehensive analysis based on multi-scale. However, for the study of moisture damage resistance of asphalt pavement, different scales have their own advantages and disadvantages. In view of this, this paper comprehensively analyzes the moisture damage resistance of asphalt pavement in salt and acid erosion environments based on three scales namely asphalt binder scale, asphalt-aggregate scale and asphalt mixture scale, and draws the following main conclusions: 1) On the whole, the deterioration tendency of salt and acid solution on the water stability mechanical strength of asphalt pavement is basically the same, and the specific order is acid rain (pH = 3) > 16 % seawater > 16 % NaCl > 8 % seawater > 8 % NaCl > distilled water > drying, indicating that salt and acid solution will aggravate the moisture damage of asphalt pavement, especially the acid rain with stronger corrosion effects. 2) The moisture damage resistance of asphalt-aggregate scale is weaker than that of asphalt binder scale and asphalt mixture scale. 3) The difference of moisture damage resistance test results between asphalt-aggregate scale and asphalt mixture scale in salt solution environments is smaller than that of other non-salt solutions. 4) The BBS test of asphalt-aggregate scale can effectively evaluate the self-healing performance of asphalt pavement. The self-healing ratio increased as the acid solution concentration increased, but the initial bond strength of BBS after high-concentration acid erosion was too small, so the bond strength after healing was still smaller than that of low-concentration acid solution. 5) The rotational viscosity of asphalt binder at 135 °C correlates well with the self-healing performance of asphalt pavement.