Influence of nanoparticles on age-associated mechanical properties of cement asphalt mortar

Abstract

The early-age mechanical properties of cement asphalt mortar (CAM) directly influence the process and quality of non-ballasted track during construction. In order to shorten the long curing period of CAM during the construction of non-ballasted track and accelerate the procedure, nano-SiO2 (NS) and nano-TiO2 (NT) were added to CAM in this study; this also improved the age-related mechanical properties of CAM, especially at early ages. Compressive strength tests were conducted at five different ages to investigate age-related compressive behaviors of CAM with nanoparticles. The results show that NS and NT can greatly enhance the early-age development of CAM and that CAM with nanoparticles accelerates the construction process and optimizes railway management. A stress–strain model of CAM was extracted to describe compressive behaviors of CAM modified by NS and NT at different ages. Finally, the microstructure of specimens was studied with scanning electron microscopy to better understand the mechanism of age-associated mechanical properties of CAM, with and without nanoparticles.