Development of the stiffness damage test (SDT) for characterisation of thermally loaded concrete

This paper describes the use of the Stiffness Damage Test (SDT) technique for quantifying the degree deterioration experienced by thermally loaded concretes. The applicability of the SDT for assessing temperature damaged concrete has been experimentally investigated and analysed. Results have shown the SDT parameters to be sensitive to the influences of test age, the level of temperature exposure and the degree of damage caused by that exposure. A strong and consistent degree of correlation between the results obtained from the SDT and the standard test measurements (compressive strength, static modulus and ultrasonic pulse velocity) has been found. The use of the SDT as a tool for detecting pre-damage and the development of microcracking in concrete specimens subjected to compressive loading have been confirmed by Acoustic Emission (AE) test techniques.