Development of a kinematic model for concrete cover spalling considering internal pressure

Abstract

Concrete cover spalling can be caused by several reasons, one of which is spalling related to reinforcement‐induced stresses. In this work, in particular spalling induced by a uniform radial pressure, which is relatable to a corroding rebar or bond pull‐out failure, is considered. Based on the kinematic theorem, two analytical modeling strategies are developed that predict the peak pressure, that is, the strength, during concrete cover spalling for both single and multiple rebars by assuming a generally acceptable failure pattern and a kinematically allowable displacement field. A fracture mechanics‐based Finite Element (FE) model is developed and validated using experimental results from the literature. This FE model is used to qualitatively assess the suitability of the assumed failure pattern and kinematics of the system in the proposed analytical models. While the numerically predicted and analytically assumed crack patterns agreed reasonably well, noticeable differences between the predicted and assumed kinematics of the system were observed. Although the developed model makes use of an upper bound theorem, the proposed analytical models correspond reasonably well with the experimental results from the literature.