Simulations of long-term bridge deck deterioration due to corrosion

The corrosion of reinforcing steel is an important factor in deterioration of concrete bridges. This phenomenon is a significant problem in the field of bridge deck maintenance, repair and rehabilitation, especially in states that commonly utilize de-icing chlorides in winter. An effective maintenance strategy requires a reliable and accurate predictive model for the deterioration process. This research proposes a comprehensive methodology to model corrosion-based deterioration in concrete bridge decks. This includes predicting the times associated with diffusion of chlorides, initiation of steel corrosion, and damage in the form of delamination up to the end of service life. This work is accomplished by: 1) proposing modifications and enhancements to existing deterioration models, 2) utilizing parametric results from non-linear finite element models to quantify growth of cracking and delamination, and 3) using the Monte Carlo simulation tool to develop reliability data for each stage in the deterioration process. The results of the developed methodology were verified by comparing estimated reliabilities at different deck ages with the bridge deck raiting information from the National Bridge Inventory data on all Wisconsin bridge decks.