1. The resistance to separation of mortar and concrete from reinforcing steel (or other materials) with which it is in contact. 2. All forces that resist separation, such as adhesion, friction due to shrinkage, and longitudinal
shear in the concrete engaged by the bar deformations. 3. The applied unit load in tension, compression, flexure, peeling, impact, cleavage, or shear required to break an adhesive assembly, with failure occurring in or near the plane of the bond.