Role of slanted reinforcement on bending capacity SS beams

Abstract

The wide application range of simply supported beams in building construction, has always caused an attraction to somehow increase their bending capacity with high ductility. In this research, for the very purpose, the reinforcement bars under compression are bent at 45° from 1/3 of the beam length from the two ends and led to the tension zone. A sealed rubber tube of diameter twice that of the reinforcement bar covers the slanted part to separate it from the beam’s concrete. This will in fact reduce the stress intensity created in the bars above and below the neutral plane and increase the beam’s bending capacity considerably through making the two tensile and compressive forces acting opposite to each other. Actually, the proposed system can be specified by applying a superposition of the sum of the effects of the compressive stresses of the reinforcement bars above the beam’s 1/3 ends plus the sum of the effects of the tensile stresses created at 1/3 of the beam midpoint. The compressive stress created in the upper part tends to pass through the slanted part and reach the tensile part, and an opposite act for the tensile stress created in the lower part. Therefore, it is obvious that a compressive force found by the solution of the first superposition equation is applied at the middle 1/3 of the lower part and causes up to 25 % increase in the beam bending capacity.