EFFECT OF THICKNESS OF CONCRETE COVER ON SHEAR-TORSION INTERACTION - AN EXPERIMENTAL INVESTIGATION

A study was conducted to investigate the effect of increasing thicknes s of the concrete cover on behavior of reinforced concrete sections su bjected to combined shear and torsion. Seven large reinforced concrete beams with two different thicknesses of concrete cover were tested at different shear-to-torque ratios, and relatively low bending. The tes ting program, experimental results, and interaction diagrams are prese nted. It is shown that increasing thickness of the concrete cover can substantially increase the strength of sections subjected to pure sile nt; or combined shear and torsion, but that it results in an undesirab le increase in crack spacing. It is also shown that sections subjected to combined shear and torsion experience lateral curvature.