On typical inhomogeneities controlling dynamic disintegration of concrete structures

Abstract

For the disintegration of aged concrete structures in densely populated urban areas, use of safer and more controllable electric discharge impulses (EDI) may be time-wise and space-wise efficient. Surrounded by other structures, very careful treatments of dynamic fracture in these aged structures are required, but the mechanical details of three-dimensional fracture development subjected to dynamic impact by EDI have not been fully understood yet. Here, we consider some typical structural inhomogeneities that may affect or be utilized for controlled dynamic fracture in such concrete structures. By performing field fracture experiments and tracing dynamic disturbances with finite difference simulations, we find the controlling effects of free surfaces, empty dummy holes and reinforcing steel bars. Not only the “connecting/sandwich effect” of outer free surfaces and empty dummy holes but also the newly identified “virtual interface effect” of reinforcing steel bars to guide dynamic EDI-induced waves can be used in real disintegration work to crush and remove only desired parts of concrete structures that need renovation.