Temperature dependence of interface shear behavior of cemented paste backfill-rock

ABSTRACT: A thorough understanding of the mechanical behavior of the interface between cemented paste backfill (CPB) and rock under different curing temperatures is critical for the safe and economical design of CPB structures. However, to date, only limited studies on the mechanical response of CPB-rock interface have been conducted, and none of them has considered the effects of temperature on the shear behavior and properties of CPB-rock interface. In this paper, the authors present experimental results of the change of shear behavior and strength of CPB-rock interface with curing temperature (20°C, and 35°C) and time. The obtained results show that the temperature can either positively or negatively affect the shear strength of the CPB-rock interface depending on the curing time. The high curing temperature (35°C) increases the shear strength of the early age interface samples, as a result of accelerated cement hydration. But for samples cured for 28 days, the sample cured at a temperature of 35°C experiences lower shear strength than that cured at 20°C. The findings in this paper contribute to a better assessment of the stability of CPB structures, and are also important for barricade design.