Interrelation of Splitting and Flexural Cracks in RC Beams

The durability of reinforced concrete (RC) structures depends mainly on concrete permeability that allows the aggressive agents to reach the reinforcement and to start corrosion. In addition to the permeability connected to porosity and microcracking, another important and well-known cause of degradation is concrete cracking that directly exposes the reinforcement to aggressive agents. Besides flexural cracks, other kinds of cracks can occur in RC beams, of which splitting cracks have particular relevance. They develop longitudinally along the anchored bar and expose a large area of the bar to the environment so that the corrosion resistance to splitting cracks should be lower than the resistance to flexural cracks. To study the structure durability related to splitting cracks, two aspects should be considered: (1) The resistance to corrosion for a given splitting crack opening; and (2) the evaluation of the splitting crack width. To shed some new light on the second aspect, in this paper a relationship between the maximum splitting crack opening and the flexural crack opening is proposed and contrasted with experimental results. Furthermore, an approximated relationship, for practical use, is determined.