On the Flexural Rigidity of Reinforced Concrete Beams

Abstract

It is general that the ordinary straight-line theory does not meet with success for evaluating the flexural rigidity of reinforced concrete beams. The co-operation of concrete between two successive cracks with the tensile reinforcement should be taken into account for its exact calculation. In this study, from the tensile loading test results on axially reinforced concrete prisms the mechanical behaviour of co-operation between concrete and reinforcement in tensile zone of beam is primarily discussed ; and the behaviour discussed is introduced into the development of the theoretical equation of flexural rigidity of cracked beams. The theory developed was verified by the experiments on simply supported reinforced concrete beams. Furthermore, some prospective way of clarifying the opening-up of crack width as well as the spacing between two successive cracks of beams is also discussed on the basis of tensile behaviour of axially reinforced concrete prisms.