Precise dynamic disintegration of concrete structures by controlling wave motion

Abstract

By applying more safely usable electric discharge impulses and based on the theory of wave and fracture dynamics, we try to establish more effectively controllable techniques for precise partial disintegration of concrete structures. The models experimentally examined in the field and numerically studied in the laboratory include (un)reinforced concrete blocks, realistically large concrete slabs and steel-concrete composite structures. In order to guide three-dimensional wave interaction and ensuing dynamic fracture development in the models exactly as desired, we make use of free surfaces and pre-existing planes of weakness such as interfaces between concrete, reinforcing steel bars, steel girders and headed stud shear connectors. We also introduce, in addition to blast holes containing energy sources and emitting waves, empty dummy holes and slits in the models, and find that the development of fracture network and the final structural disintegration pattern depend sensitively on the geometrical settings of the above inhomogeneities. Our ultimate goal is to crush and remove only concrete material while other parts of structures like headed stud shear connectors and steel girders remain undeformed for later renovation work, even in densely populated urban areas.