Analysis on factors affecting moisture stability of steel slag asphalt concrete using grey correlation method

The moisture sensitivity of steel slag asphalt concrete has been receiving close attention from the road construction industry. Although researchers have conducted numerous studies on the water damage resistance of steel slag asphalt concrete, the evaluations are inconsistent, and it is difficult to distinguish the weighting ratios of the factors influencing the moisture sensitivity of asphalt concrete in the current study. Based on the water immersion Marshall test, freeze-thaw splitting test, and Hamburg rutting test, this study tested the water stability of asphalt concrete prepared from steel slag by different processes, aiming to illustrate the influence of the preparation process of aggregates on the water sensitivity of asphalt concrete. The results showed that the water stability of asphalt concrete prepared from steel slag obtained by the roller method and the hot smothering method was better than that of limestone asphalt concrete, while the water stability of asphalt concrete prepared from steel slag was inferior to that of limestone concrete. Subsequently, the adhesion between the three steel slag and limestone respectively and asphalt was compared in the modified boiling method, and the surface morphology structure of the four aggregates was characterized by scanning electron microscopy (SEM), and the results showed that the adhesion between the aggregates and asphalt was consistent with the moisture sensitivity of asphalt concrete. Finally, the comprehensive analysis concluded that the main factors affecting the water stability of steel slag asphalt concrete were asphalt, aggregate, gradation, and particle size, in that order.