Numerical simulations of crack path control using soundless chemical demolition agents and estimation of required pressure for plain concrete demolition

Abstract

In demolition process of large concrete structures, the non-explosive methods can be advantageous in reducing noise, vibration, and dust emission compared to the conventional explosive methods. One of the representative non-explosive methods is the injection of soundless chemical demolition agents (SCDAs) into the holes drilled in concrete structures and further expansion of the SCDAs. In the current paper, a computational framework was established and applied to simulate crack initiation and propagation caused by slow expansion of the SCDAs in plain concrete structures from a theoretical perspective. Using the concrete damaged plasticity model for semi-infinite structures, we first determined a proper domain size for the demolition simulation and then investigated a cost-effective spacing of the SCDA holes arranged horizontally or vertically. The interaction between the SCDAs was examined in terms of the minimum expansion pressure required to form cracks connecting the SCDAs. Furthermore, we found an equation for the minimum expansion pressure required to control a U-shaped crack path as a function of SCDA spacing and concrete compressive strength.