Watching the bonding between steel rebar and concrete with in situ X-ray imaging

Pull-out tests combined with an in situ radiographic movie are presented in order to investigate bond properties between steel rebar and concrete during tests on concrete reinforcement samples. Rebar relative displacement and other theoretically anticipated properties during the loading process, such as regions inside the concrete with maximum compression and longitudinal cracks, could be visualised and detected. Future studies on corrosion of reinforcement using such a combined technique are envisaged.