Correlation between damage parameters and mechanical proper-ties of concrete affected by ASR

To investigate the potential correlation between damage parameters used to assess the level of alkali silica reaction (ASR) in concrete and the mechanical properties of the material is a promising approach. Currently, ASR damage evaluation of concrete is done following FHWA protocol [1]. The actual lev-el of damage (diagnosis) is evaluated using the Stiffness Damage Test (SDT) and the Damage Rating Index (DRI). Both methods provide parameters cor-related to the concrete's expansion level. In addition, future potential of damage (prognosis) is assessed using residual expansion tests in specific cli-matic conditions (R.H. >95 % and T = 38+/-°C) and alkaline solution (NaOH 1N, 38+/-°C). Expansion is thus currently used to assess the damage and predict future deterioration. However, only expansion measurements are in-sufficient for infrastructure managers who need to understand the structural impact of ASR on concrete structures. Therefore, this research aims to iden-tify new correlations between the actual test results and structural parameters of the concrete, providing more relevant information for infrastructure man-agement. In this project, cores from ASR-affected bridges were extracted, cut into samples and subjected to both prognosis and diagnosis tests, as well as compressive tests, directly after extraction and after expansion tests, respec-tively. A linear trend was identified for compressive strength, correlating with DRI values in cores tested after extraction, indirectly linking to the con-crete's expansion level. Young's modulus also decreased with additional ex-pansion during the tests, but no significant trendline was identified.