Modeling the microstructure at steel: Concrete interface in reinforced concrete

The microstructure at the steel–concrete interface can significantly affect corrosion of steel and corrosion-induced cracking of reinforced concrete (RC). This paper aims to model the thickness of porous band around the steel–concrete interface as a function of concrete design parameters. Both the maximum (d0,max) and equivalent uniform thickness ((Formula presented.) 0) of the porous band are thoroughly examined. The developed model is robust in predicting the thickness around the steel–concrete interface, the maximum and equivalent uniform thickness of the porous band. It is found in the paper that water to cement ratio and concrete cover show strong correlations with the porous band (d0) while aggregate size shows no correlation. The contribution of the paper is that the developed models for porous band around the steel–concrete interface can improve the prediction of corrosion-induced cracking of RC and hence prevent premature and avoidable failures of corrosion affected concrete structures. © 2019 fib. International Federation for Structural Concrete