ABSTRACT

External sulphate attack (ESA) interferes with spatial changes in fracture toughness of cemented paste backfill (CPB) and affects its mechanical stability. Large-scale curing column models are developed to investigate the spatial evolution of mode-I and mode-II fracture toughness (i.e. K_IC and K_IIC) under seepage- and diffusion-induced ESA. It has been found that the seepage-induced ESA leads to spatial changes in K_IC and K_IIC of CPB at advanced ages and higher extent of degradation of fracture toughness is measured at a deeper position in CPB. Comparatively, K_Ic can be used as a reliable quantity to estimate K_IIc under the diffusion-induced ESA.

摘要

外部硫酸盐侵蚀 (ESA) 会干扰水泥浆回填材料 (CPB) 断裂韧性的空间变化，并影响其机械稳定性。开发了大型固化柱模型来研究渗流和扩散诱导的 ESA 下I 型和 II 型断裂韧性（即 K _IC和 K _{IIC ）的空间演化。}研究发现，渗流引起的 ESA 导致高龄 CPB 的K _IC和 K _{IIC空间变化，并且在 CPB 较深位置测量到断裂韧性的退化程度较高。}相比之下，K _Ic可以作为估计扩散诱导 ESA 下K _{IIc的可靠量。}