Nonlinear Gel Migration in Cracked Concrete and Broken Symmetry of Corrosion Profiles

Abstract

The initiation and subsequent propagation of corrosion-induced cracks is simulated by multi-phase mechanics where the coupled corrosion gel migration and crack-based fracture can be coherently taken into consideration. A key focus is given to the nature of corrosion products and their dependency on the corrosion rate and the anisotropic stiffness and permeability caused by cracking. Migration of corrosion gel to both micro-pores of cementitious composites and crack gaps are explicitly considered under the gradient of gel pressure, which is newly defined on the corrosion gel phase. The effects of cover depth, corrosion rate and the mix-proportion of concrete on the crack initiation and propagation are discussed with experimental facts. The broken symmetry of corrosion profile around reinforcing bars is successfully simulated as a nature even though the geometry of analysis domains would be in perfect symmetry. This scheme which allows kinematics of produced gel is indispensable for a versatile framework of durability mechanics.