Abstract
The concept of the effective cover thickness was applied to predict the deformation and ultimate strength of reinforced concrete members subjected to pure torsion. The principal compressive strain was applied as an index of the effective cover thickness in order to evaluate the effect of cover thickness on the torsional strength. The predicted behavior using the reinforced concrete plate model showed good agreement with experimental data. When the concrete cover is spalled out at ultimate state, the shear flow should flow inner to the reinforcement cage. Therefore, the ultimate strength assuming the center line of lateral reinforcement as the perimeter of shear flow was investigated. The space-truss model was applied for calculating the ultimate torsional strength. It was found the proposed method was applicable for predicting the ultimate torsional strength of reinforced concrete members.
