1. Introduction
1.1. General
A monolithic construction of reinforced concrete structure
tends to introduce torsional moments into the members which,
in general, cannot be ignored in design. Torsional strength of sections
made with homogeneous materials can be estimated quite
accurately using the theory of elasticity. However, it is very difficult
to assess the torsional strength of heterogeneous reinforced
concrete sections. The problem becomes even more acute because
such members are seldom under pure torsion; rather they are subject
to bending, shear and torsion [1].