On the necessity of a non-slip mechanism between steel and concrete in the region of a crack

Experiments have suggested that the width of a crack occurring in reinforced concrete in flexure becomes zero around the reinforcement. In this paper it is shown that the bond mechanism of no-slip, although obviously sufficient, is not necessary in order that these closed regions of a crack may occur. This allows theories of cracking to proceed unhampered by unduly restrictive conditions on bond.