Conditions for Failure of Normal Section in Flexural Reinforced Concrete Beams of Rectangular Cross-Section

The stress in longitudinal tensile reinforcement is one of the main important parameters while examining the technical state of under- reinforced concrete structures. The most important issue is to determine whether the external loads cause the close to yield stress in the main reinforcement. Yield stress in tensile reinforcement could be treated as the start of incipient failure of the flexural structure. The state of tensile reinforcement of flexural reinforced concrete structures could be examined by observing the properties of the normal cracks. The application of fracture mechanics of solids could be used for determining the actual damage to the structure by knowing only the measured height of the normal crack.