SHEAR CRACK RESISTANCE OF REINFORCED CONCRETE TAPERED BEAMS

Despite the widespread use of tapered beams, the features of their stress-strain state remain poorly understood, including in regions near curvatures of the faces.A lot of experimental studies have shown that in tapered beams, shear cracks occurs not only in the support zone, but also in the middle of the span directly at the apex, even without shear force. Based on the full-scale tests of tapered beams and finite element analyses, diagrams of shear and transverse stresses are constructed. The data obtained revealed differences in the stress distribution in tapered and linear beams. The features of the stress-strain state of the tapered beams are associated with the occurrence of shear stresses from the action of the bending moment and longitudinal force due to the variable depth of the section of the element, as well as with the formation of local stress fields in areas near the curvatures of the faces. The proposed analytical dependences allow us to calculate shear and transverse stresses in the apex zone of tapered beams and determine the moment of occurrence of shear cracks in the specified zone.