A torsion test to evaluate the deterioration of concrete due to alkali-aggregate reaction

A new type of strength test is described in which concrete cores are subjected to torsional loading. The resulting shear stress state, on a representative volume of concrete, is used to evaluate the shear strength properties of the concrete. Two rigs have been developed: one for site use and one for more refined laboratory testing. The rigs and test procedures are described, some preliminary test results are presented, and the significance of the results is discussed. It is suggested that the method may have a wide application in quality control of new construction and assessment of deteriorating concrete strength in existing structures.