HEAT AND PRESSURE DEVELOPMENTS IN CHEMICAL DEMOLITION AGENTS

Chemical-based demolition has been commercially available since the 1970s, although not widely applied, in part because of an absence of rigorous usage guidelines. However, both laboratory and field work has shown their viability as an effective alternative to traditional demolition methods, as it is noise and vibration free and, thus, attractive for use near historic structures and environmentally sensitive areas. While the available commercial products are known to generate heat and pressure, the formation and progression of those factors have not been well documented. Understanding of these factors can provide critical insights into developing procedures for the highly selective application of such materials both near and within historic structures. To this end, this paper presents a heretofore unpublished study on the development of heat and pressure in a metal pipe filled with a chemical demolition agent. The laboratory study employed a strain-gauged pipe filled with the material and a thermal camera that visually captured the highly irregular temperature development within the pipe. This paper presents the onset and evolution of heat within the pipe and the accompanying pressure development. Results showed the peak heat generation after 72 minutes. Rapid pressure gain began approximately 70 minutes before this when the sample reached 54.5 C.