Experimental Study of Torsional Reinforcement in R.C. Slab with Four Edges Discontinuous

Abstract — The twisting moments can become significant at points along the slab diagonals and the variation of principal moments is along and across a diagonal of simply supported and uniformly loaded square slab of homogeneous material, as obtained from an elastic analysis. If downward reactions cannot be developed at the supports, the corners will be lifted up. By providing torsion reinforcement, corners are usually prevented from being lifted up. In such cases the corners have to be suitably reinforced at top and also at bottom otherwise cracks are liable to be formed at the corners. The present investigation is intended to study the influence of torsion reinforcement in reinforced concrete slab with end condition all ends discontinuous under uniformly distributed load. Slabs with torsion reinforcement varying from 20 % to 35% were casted and tested. Increasing in the torsion reinforcement controls the deflection of the slab element. As the torsion reinforcement increases the corners are being held down. At the maximum of 35 % of main reinforcement was provided as torsion reinforcement corners are not held down completely and there is a considerable decrease in central deflection also. Index Terms — Torsion reinforcement, central deflection, Slab