E-modulus of the alkali–silica-reaction product determined by micro-indentation

• First experimental data on E-modulus of ASR product present in concrete aggregates.
• Detailed chemical analysis of ASR product present in concrete aggregates.
• E-modulus of ASR product can improve accuracy of models assessing effects of ASR on structures.

The effects of expansion on concrete structures induced by alkali–silica reaction (ASR) are complex. Numerous attempts have been made to model them. Some of these models assume an E-modulus for the ASR product, as no experimental data exist up to now.In this study, Vickers hardness, indentation and E-modulus are determined by micro-indentation tests on undried, polished concrete samples taken from a structure damaged by ASR. Both the indentation tests and the chemical analysis by EDX performed on the ASR product in different aggregates indicate that it is relatively homogenous. Vickers hardness ranges between 10 and 19 and E-modulus between 7 and 9 GPa. Towards the edge of the aggregates the ASR product takes up calcium and the values for Vickers hardness and E-modulus increase.