Using Chemicals as Demolition Agents Near Historic Structures

When selective demolition of rock and existing concrete is required near historic structures, there are always concerns about vibration-induced damage from either explosives or other percussive means, such as jackhammers. Soundless chemical demolition agents (SCDAs) offer an alternative.  Although not widely applied, this non-percussive approach can be highly effective. The following paper outlines a set of usage considerations for SCDAs near historic structures.  As part of this, the relative advantages and disadvantages are discussed including appropriate environmental conditions, and the quantity of material needed (along with the affiliated costs). Performance information related to the timing and extent of cracking is also provided. Furthermore, critical portions of this paper relate to the necessary preparatory work, training, safety precautions, and storage requirements needed when using this class of products, including emergency precautions. Finally, this paper briefly summarizes the application of one SCDA product as part of the 2001 Carnegie Hall expansion.