Quality of the bond between a Strain Hardening Cement Composite stay-in-place formwork and concrete: Comparison of two experimental set-ups

Strain Hardening Cement Composites (SHCC) have recently been investigated as a material for strengthening and retrofitting of existing concrete structures or as stay-in-place (SiP) formwork for new concrete structures. However, for efficient utilisation of SHCC in composite structures, the debonding mechanism between SHCC and concrete must be understood. This paper compares two different double-lap shear test set-ups to investigate the bond between SHCC-SiP formwork and concrete. The investigation concludes on the performance of these tests (symmetrical behaviour, repeatability), their critical analysis and the quality of the results. It validates digital image correlation as a full-field slip measuring technique which moreover allows to determine the effective bond length.