Cross-scale study on the influence of moisture-temperature coupling conditions on adhesive properties of rubberized asphalt and steel slag

Abstract

In order to study the effects of moisture and temperature on the interfacial adhesion characteristics between rubberized asphalt and steel slag, the interfacial adhesion properties between rubberized asphalt and steel slag under different immersion temperatures were studied. At the molecular scale, the interaction between rubberized asphalt model and steel slag representative minerals (Ca3SiO5 and Ca2SiO4) models were studied by molecular dynamics simulation. The bonding properties between rubberized asphalt and steel slag were analyzed and studied by direct tensile bonding failure test at macro scale. Through the correlation analysis between the macro scale direct tensile bonding failure test results and the molecular scale interface interaction, the cross-scale performance of moisture temperature on the adhesion characteristics between rubberized asphalt and steel slag was revealed. The results show that the type of interaction between steel slag molecules and asphalt molecules is consistent with that of natural minerals, and they all interact by hydrogen bond. Water molecules on the surface of steel slag molecular distribution is in a stepped pattern, asphalt molecules on the surface of steel slag molecular distribution are more uniform. Under the influence of rising temperature, water molecules further gather to the surface of steel slag molecules, and asphalt molecules gather away from steel slag molecules. When the temperature rises from 40 °C to 50 °C, the interaction energy density between rubberized asphalt and steel slag molecules hardly changes, and the interaction energy density decreases significantly when the temperature rises to 60 °C. Under the action of tensile stress, Ca2SiO4 shows weaker interaction with rubberized asphalt, while the interface of Ca3SiO5 and rubberized asphalt is less affected by external force. At the same time, 60°C is more obvious as the threshold temperature of interface strength decline under the action of external force. There is a good power function correlation between the macro bonding failure energy density and the molecular interaction energy density. The regularity within each scale is consistent, which confirms the rationality of cross-scale analysis of the same observation object between different scales. However, there are still great differences in the absolute values of indexes between different scales, which indicates that the simple numerical correspondence cannot be carried out in the cross-scale analysis due to the different ideal degree of models.