In order to explore the effect of coral reef powder content on the relationship between microstructure characteristics and macroscopic mechanical properties of emulsified asphalt, and promote the resource utilization of coral reef waste, this paper systematically studied the performance evolution of emulsified asphalt under different coral reef powder content through penetration, ductility, softening point, Brookfield Viscosity, dynamic shear rheology, multi-stress creep recovery and infrared spectroscopy tests. The grey correlation theory was used to analyze the correlation between content, microscopic index and macroscopic performance. The results show that with the increase of coral reef powder content, the penetration, ductility, 135 °C and 180 °C Brookfield Viscosity of emulsified asphalt increase first and then decrease, while the softening point decreases first and then increases. When the content is 12%, the conventional properties show a better balance. Infrared spectroscopy showed that the index of sulfoxide group (S=O) and butadiene group (C=C) changed regularly with the content, indicating that the incorporation of coral reef powder affected the chemical environment and interaction of asphalt components. In terms of rheological properties, the appropriate amount of coral reef powder can improve the elastic response of asphalt, and its viscoelasticity is more balanced at 12% content. In the multi-stress creep recovery test, the increase of the content makes the creep recovery rate R3.2 and the unrecoverable creep compliance Jnr3.2 both increased. Grey correlation analysis shows that there is a clear correlation between the content of coral reef powder and the macroscopic properties of asphalt, among which the effect on Tan δ (phase angle tangent value) is the most significant. Among the microstructure indexes, S=O index and C=C index have the highest correlation with penetration, followed by softening point and high temperature creep parameters, and the correlation with G*/sin δ is relatively weak. In summary, coral reef powder can significantly regulate the microstructure and viscoelastic behavior of asphalt through the physical filling effect brought by its porous structure and the interfacial interaction between surface active groups and asphalt components. The synergistic optimization of macroscopic properties can be achieved at a suitable dosage (such as 12%). This study provides a theoretical and experimental basis for its rational application in emulsified asphalt.
Hu et al. (Wed,) studied this question.