Prediction of concrete crack width under combined reinforcement corrosion and applied load

As a global problem for reinforced concrete structures located in a chloride and/or carbon dioxide laden environment, reinforcing steel corrosion in concrete costs approximately $100 billion per annum worldwide for maintenance and repairs. The continual demands for greater load for infrastructure exacerbate the problem. This paper attempts to examine the whole process of longitudinal cracking in concrete structures under the combined effect of reinforcement corrosion and applied load. A model for residual stiffness of cracked concrete is derived using the concept of fracture energy. It is found that the corrosion rate is the most important single factor that affects both the time-to-surface cracking and crack width growth. The paper concludes that the developed model is one of very few theoretical models that can predict with reasonable accuracy the crack width on the surface of reinforced concrete structures under such a combined effect. The developed model can be used as a tool to assess the serviceability of corrosion-affected concrete infrastructure. Timely repairs have the potential to prolong the service life of reinforced concrete structures.