Coupled effects of curing stress and curing temperature on mechanical and physical properties of cemented paste backfill

In order to disposal the tailings and improve the safety of mines, the cemented paste backfill (CPB) technology has been widely applied to the mines all over the world, and the index of uniaxial compressive strength (UCS) for CPB is one of the most important factors to guarantee the safety of the filling stopes. However, there is little information regarding the coupled effects of curing stress and curing temperature. This study is aimed to investigate the coupled effects of curing stress and curing temperature on the physical and mechanical properties of CPB. Thus, the CPB samples were cured at different curing stress and curing temperature, also the mechanical and physical parameters were frequently tested, the microstructure of CPB was tested by the X-ray diffraction (XRD) and thermal gravity analysis (TGA). The results show that both the curing stress and curing temperature can affect the cement hydration reaction rate, resulting in more hydration products, which is contribute to the UCS acquisition. On the other hand, the water content, dry density and stress-strain curve of CPB were greatly influenced. The results demonstrate that the coupled effects of curing stress and curing temperature should be considered when designing a cost-effective and safety CPB in the underground mines, which can provide technical guidance for the mines. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study found that curing stress and curing temperature have coupled effects on the physical and mechanical properties of cemented paste backfill (CPB), influencing the hydration reaction rate and UCS acquisition. They also significantly impact the water content, dry density, and stress-strain curve of CPB.