Soundless chemical demolition agents performance under cold and cool temperatures in concrete and masonry structures

There are several commonly used traditional demolition methods such asjackhammers, explosives, controlled blasting and diamond wire saws.Unfortunately, these traditional methods produce high levels of noise, vibration anddust. As such, demolition of rocks, existing concrete structures, historic structuresand densely populated areas always raises concerns. In such cases, SoundlessChemical Demolition Agents (SCDAs) offer a reliable alternative. This PhD thesisfocuses on SCDA performance under cold and cool temperatures by means of foursets of experimental work. Across these tests, the relationship between ambienttemperature, heat of hydration, volumetric expansion, calcium hydroxide Ca(OH)2and calcium carbonate (CaCO3) were monitored under different ambienttemperatures and conditions. As a part of these tests, the impact of the thermaltransfer likely to be present during concrete demolition and its effect on thehydration heat development and pressure generation was considered. Resultsindicate that higher ambient temperature results in higher heat of hydration andhigher expansive pressure development. The relationship between ambienttemperature, volumetric expansion and calcium hydroxide Ca(OH)2 generation wasalso investigated. In the last part of this thesis, SCDAs were used for selective andpartial removal of masonry units. The experimental results show that partialremoval was successful, although selective targeted removal of individual masonryunits removal was not possible by hand, despite significant cracking in the area.