Mechanical Properties of Cement Asphalt Mortar under Low Temperature Condition

摘要

Cement asphalt (CA) mortar is a composite material used in the non-ballast slab track of high-speed railways. The behavior of CA mortar under the exterior environmental actions is essential to the safety of high-speed railways. In this article, the low-temperature behavior of CA mortar was investigated. The compressive test of CA mortar at the temperature of -20 degrees C and 0 degrees C was conducted first, and the stress-strain curves and mechanical properties were experimentally determined to analyze the effect of low temperature. Nanomaterials were also included in CA mortar to improve the performance of CA mortar at low temperatures. The results indicated that the descending branch of stress-strain curves of CA mortar is closely related to the temperature, and the compressive strength and elastic modulus of CA mortar were decreased with temperature with different decreasing patterns. Nanomaterials were also found to be favorable to the ductility of CA mortar. Based on the experimental observations, a stress-strain model of CA mortar to describe the performance of CA mortar at low temperatures was finally proposed and verified.