Controlled disintegration of reinforced concrete blocks based on wave and fracture dynamics

Abstract

In this contribution, field experiments of dynamic fracture by electric discharge impulses (EDI) are performed and fracture development in rectangular concrete blocks with reinforcing steels bars is analyzed also numerically in the three-dimensional context. It is found that the development of fracture network depends very sensitively on the geometrical settings (e.g. positions of empty dummy holes prepared for controlling crack propagation directions) in the blocks, and cracks extending from blast holes may tend to arrest on the (pre-)existing planes of weakness (e.g. interfaces between concrete material and reinforcing steel bars). This characteristic can be used to actualize more efficient and precise disintegration of a given structure, for instance, removal of reinforced concrete (RC) lining segments from the surroundings in an underground space. Optimal positions of blast and empty dummy holes for predictable and controlled dynamic destruction may be determined for each specific structure by the established simulation technique, which is effective for both conventional and modern dynamic disintegration methodologies, namely, fragmentation by blasting using explosives as well as by EDI.