Stochastic Assessment of Timing and Efficiency of Maintenance for Corroding RC Structures

Reinforced concrete (RC) structures in a chloride environment are exposed to a particularly aggressive form of deterioration. Managing the maintenance and repair of structures subjected to these conditions is an important issue facing asset owners and operators. In the present paper, the criterion for repair is the extent of corrosion induced cracking. Common maintenance criteria and maintenance techniques are described and these are incorporated into a two-dimensional spatial time-dependent reliability model. This allows the number, timing, and extent of maintenance actions to be predicted over the service life of RC structures. The analysis includes the effect of inspection interval, maintenance technique, repair efficiency, and repair threshold. Results are presented for a typical RC bridge deck subject to a corrosive marine environment. It was found that repair efficiency affecting time to corrosion initiation of repaired concrete is more critical to the performance of the repair than the repair efficiency that affected corrosion rate.