Experimental study on improved static cracking demolition agent self-swelling cartridge fracturing mechanism and mode of failure of concrete under preset axial compression loading

Non-explosive rock and concrete breaking technology is extensively employed in rock breakage and demolition projects. As underground engineering advances to greater depths, the stress conditions impact on the rock breakage process. Safety and environmental concerns have become frontal issues in mining and tunnelling. Consequently, understanding the non-explosive rock and concrete breaking mechanisms under the influence of in-situ stress becomes crucial. Equally important is the challenge of identification of the appropriate non-explosive rock breaking material and technology. In this paper, a self-swelling cartridge (SSC) that was designed and developed from standard static cracking demolition agent (SCDA) to overcome deficiencies in its commercial production and rock and concrete breaking efficiency is reproduced from an improved SCDA. The improved SCDA includes a super absorbent polymer (SAP). The optimum performance characteristics of the SSC from the improved SCDA were determined from laboratory experiments. The laboratory test results show that the optimum amount of SAP required in the SCDA is 9%, the SSC density is 1.9 g/cm3 and absorbed water and ambient temperatures of 20 °C and 40 °C respectively. Under these optimum conditions, the SSC achieved a maximum expansion pressure of 29.05 MPa in four hours. The SSC from the improved SCDA offsets the limitations of the standard SCDA slurry and the SSC developed by Xu et al. (2021). The results of experiments with preset axial loads and prescribed maximum SSC expansion pressures show that the SSC from the improved SCDA has good potential for use in dimension stone production and rock/concrete breakage.