Evaluation of the Physicochemical Properties and Antiaging Properties of Bitumen Mastic Modified by Layered Double Hydroxides

Abstract

Layered double hydroxides (LDHs) can shield polymeric materials from UV light, which allows reducing material aging and erosion damage of bituminous pavement under physical and chemical action. In this study, the physicochemical properties, aging resistance, and erosion resistance to the aqueous solution of LDHs modified bitumen mastic (BM) were characterized by Fourier-transform infrared spectroscopy, basic physical tests, viscosity tests, a dynamic shear rheometer, and a bending beam rheometer. The results show that few chemical reactions occurred between LDHs and BM, indicating that a physical mechanism underlay the modification of BM by LDHs. Moreover, LDHs could increase the flow activation energy of BM by 0.12%, increase the high failure temperature from 69.07 °C to 71.07 °C, and decrease the low failure temperature from −10.50 °C to −12.39 °C. Therefore, LDHs could slightly reduce the temperature sensitivity of BM, while slightly enhancing the high and low-temperature rheological properties of BM. Compared with short-term aging and long-term aging, LDHs could significantly improve the UV aging resistance of BM. The above results are consistent with previous studies of LDHs-modified bitumen. Furthermore, water and pH 3 acidic solutions had the greatest degree of erosion to BM, and LDHs could improve the resistance to aqueous solutions. Overall, this study can help to investigate the effects of various environmental factors on the performance of LDHs modified bitumen pavements during long-term use.