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 f or quantifying the degree deterioration experienced by thermally loaded con cretes. The applicability of the SDT for assessing temperature damaged conc rete 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, stat ic modulus and ultrasonic pulse velocity) has been found. The use of the SD T as a tool for detecting pre-damage and the development of microcracking i n concrete specimens subjected to compressive loading have been confirmed b y Acoustic Emission (AE) test techniques.