Torsional stiffness of reinforced concrete members subjected to pure torsion

Synopsis A method is described for determining the torsional stiffness at the cracked stage of reinforced concrete members subjected to a pure torsional moment. The method is based upon a truss analogy for torsion. Theoretical expressions are deduced for the Torsional stiffness of beams of arbitrary and rectangular cross-sections. The theoretical values are compared with experimental results for rectangular beams. The applicability of the theory used is briefly discussed and a procedure is given to correct for its imperfections.