Influence of Cracks on Corrosion Initiation in Bridge Decks

Cracking of bridge deck concrete remains an important issue relative to deck durability. Cracks can allow increased penetration of chlorides that result in premature corrosion of the reinforcing steel and subsequent spalling of the surrounding concrete. It is believed that the service lives of bridge decks are affected by concrete cracking; however, to what degree is the question that needs to be answered. Crack repairs may be expensive and only a few state transportation agencies have developed effective decision-making tools to support engineering decisions about whether and how to repair cracks in bridges. This study involved field surveying, sampling, and extensive data collection from 27 highway bridge decks in Virginia. Service life estimation was conducted using a probabilistic chloride diffusion model to understand the effects of cracks on the durability of the structures. It was found that below a threshold crack frequency, cracks do not affect the service life of bridge decks significantly and, thus, do not need any repair.