Practical use of the Stiffness Damage Test (SDT) for assessing damage in concrete infrastructure affected by alkali-silica reaction

Abstract

The Stiffness Damage Test (SDT) is an interesting tool for assessing damage in concrete affected by ASR. The use of a fixed loading level for stiffness damage testing, as previously suggested in the literature, limits its ability to reliably appraise the distress level of concrete samples, especially when different concrete strengths and aggregate types are used. Moreover, the test input and output parameters should be properly interpreted so that the SDT becomes a powerful diagnostic procedure. This paper presents an evaluation of the practical use of the SDT in engineering purposes. Results show that the use of output indices, i.e. SDI and PDI, instead of absolute output values, makes the procedure more diagnostic (i.e. ≠ distress degrees can be easier distinguished) and less influenced by practical assumptions (e.g. choice of the loading level for stiffness damage testing). Based on the prior results, a step-by-step standard test procedure is proposed aiming to minimize the test variability.