Review of Concrete Beams Failing in Shear

The nature of inclined cracking in reinforced and prestressed concrete beams is examined in terms of primary cracks caused by interaction of bending and shearing stresses. Classical methods of computing the inclined cracking loads are reviewed and their relationship to current design criteria is noted. Two broad types of shear failure analyses are defined as (1) arch, truss, and frame analagies and (2) limit analysis mechanisms, and the limitations of the various methods are briefly examined. A general theoretical solution of the shear strength problem is briefly outlined which involves a numerical iterative procedure to determine the stress and strain field in a cracked reinforced concrete beam. Secondary cracks caused by slip and dowel action forces in the longitudinal bars transferring shear across the crack are described and their influence on the mechanism of failure is considered.