ASR impacts on the behaviour of mortar submitted to a pull-out test inside a X-ray tomograph

Multi-scale and multi-physics processes make understanding the mechanical impact of alkali-silica reaction (ASR) on structure challenging. This study investigates ASR’s impact on a small-scale mortar foundation subjected to reinforcement pull-out. A 1/50 scale electrical pylon foundation is tested in an X-ray tomograph at different ASR swelling stages. Finite-element-based digital volume correlation is used to analyze the structure’s behavior during loading. Results show that the pull-out resistance of small-scale foundations increases with ASR and the failure patterns change. Through measurements of displacements within the mortar, interfacial debonding, and multidirectional swelling, this increase is attributed to reinforcement prestressing caused by ASR swelling. In-situ tests combined with Digital Volume Correlation allow for precise quantification of three-dimensional displacement fields in the specimen. Such a method highlights the effects of alkali-silica reaction, enabling a quantified understanding of the relationship between structural response and pathology progression. • The evolution of material degradation are analyzed by means of X-ray CT. • Digital Volume Correlation enables quantitative analysis of ASR induced swelling. • Heterogeneous swelling, crack pattern and debonding are quantified in 3D. • This study identifies relevant mechanisms induced by ASR in the bulk.