Temperature-related Performance Factors for Chemical Demolition Agents

Soundless chemical demolition agents (SCDAs) are percussion-free alternatives to blasting for selective demolition. Although known to be temperature sensitive, to date their performance has not been quantified in ambient environments below 20°C. This paper examines 6 large-scale specimens at 16.1-19.3°C. Substantially slower response than that reported by manufacturers was documented. Initial cracking required 25 + h and continued for 4-8 days. Cracks opened rapidly after minimum demolition time [(MDT)-cumulative cracking around the perimeter reaching ~25 mm], which was at 42 and 70 h, respectively in 16.8 and 33.1 MPa specimens. Post-MDT, crack width opening velocities were 0.35-0.96 mm/h, approximately one-third to two-thirds pre-MDT velocities. A 0.5°C ambient temperature drop delayed MDT by 6.5 h amongst equi-sized specimens of the same strength. Generally, MDT correlated with material strength (irrespective of ambient temperature or specimen size), whereas time to first crack was more influenced by t...