Enhanced effect of self-propagating subsequent heating on the expansive pressure on soundless chemical demolition agent

Abstract

Soundless cracking demolition technology is an essential method for demolition of buildings in place of engineering blasting in complex environments. However, the temperature dependence of soundless chemical demolition agent (SCDA) dramatically restricts the development and application of this technology. For this reason, the enhanced effect of subsequent heating on the expansive pressure of SCDA is examined in this study. A self-propagating heating tube was designed. After determining the optimal heating time through uniaxial compressive strength (UCS), the SCDA expansive pressure measurement experiment was carried out under different heating conditions. Therefore, the enhanced effect of heating on SCDA expansive pressure was examined, and the enhanced mechanism was revealed by analyzing the microstructure and hydration products. The research results show that the UCS of SCDA has a linear relationship with the ambient temperature, and the optimal heating time can be determined by the UCS formula. After heating, the temperature and expansive pressure of SCDA increase suddenly. To reflect the influence of heating on the development of expansive pressure, a functional relationship of expansion pressure–time-ambient temperature is proposed. Heating can significantly accelerate the hydration process of SCDA and make dense Ca(OH)2 grains formed inside it. This is the intrinsic reason for the mutant growth in the expansive pressure of SCDA. This work broadens the application scenarios of SCDA and provides new ideas for the growth of expansive pressure.