Study on Splitting Damage Characteristics of a Rock–Shotcrete Interface Subjected to Corrosive Water

Splitting tensile real time acoustic emission tests were carried out on rock–shotcrete binary specimens under the action of different corrosive waters in different periods. The effect of corrosion on the damage process of the binary interface was studied from a mesoscopic point of view. The results showed that the physical and chemical properties of the binary specimens were changed due to corrosion, resulting in a decrease in the tensile strength. Moreover, the corrosion effect of the acid solution is relatively strong throughout the whole corrosion cycle. It can be seen that the acoustic emission signal can reflect the interface microcrack propagation and inoculation process from the stress–strain curve, the ringing count, and the cumulative energy correspondence. Furthermore, the peak point of each parameter decreases with deepening the corrosion degree in different corrosive environments. The same-step variation in numerical value can provide certain early warning information. The application of acoustic emission B value indicates that the failure mode of the interface of the binary body develops from the failure of large internal cracks to the failure of continuous small cracks as the corrosion intensifies. The damage model established based on acoustic emission cumulative ringing count can better characterize the coupling relationship between corrosion-load-damage of the binary.