A new type of strength test has been developed recently in which concrete cylindrical test specimens are subjected to torsional loading. The test was developed primarily to assess the strength of deteriorating concrete in existing structures. The torsional loading results in a shear stress state on a representative volume of concrete and is used to evaluate the shear strength properties of the concrete. The same testing arrangement has been used to test concrete cylinders with central circumferential notches. In such tests a Mode III type of failure was observed.