Abstract
Crack extension due to rebar corrosion is one of serious problems in concrete structures. It is well known that the mechanisms of crack nucleation and extension can be theoretically analyzed by applying fracture mechanics to concrete. For diagnostic purpose of the concrete structures, a rational model is in demand for predicting the deterioration process of rebar corrosion. Thus, an application of fracture mechanics to spalling cracks due to rebar corrosion is studied. Crack extension is observed under electrolytic corrosion of rebars. To analyze crack extension, the linear elastic fracture mechanics is applied. The critical stress intensity factor is determined from bending tests of notched beams, taking into account acoustic emission (AE) activity. Based on the maximum circumferential stress criterion, crack trajectories are analyzed by employing the two-domain boundary element method (BEM). Taking non-isotropic distribution of pressure due to corrosion product, crack trajectories of spalling cracks are simulated in reasonable agreement with those observed in the experiment.
