Cracking of SHCC due to reinforcement corrosion

Reinforcement corrosion is the most important deterioration mechanism affecting reinforced concrete infrastructures. After corrosion starts, expansive pressures are exerted onto the surrounding concrete, causing cracking and spalling of the cover concrete. The amount of cover cracking can possibly be reduced by using strain hardening cementitious composites (SHCCs). In this work, the ability of strain hardening cementitious composite to resist cracking due to corrosion of reinforcement is studied. An accelerated corrosion experiment is performed to speed up the corrosion process. Micro-computed X-ray tomography technique (CT-scanning) was used for monitoring rust formation during accelerated corrosion of reinforcement and subsequent cover cracking. Development of cracks in SHCC specimen was compared to a reference specimen. While the SHCC specimen developed a large number of small cracks, the reference specimen exhibited extensive spalling due to corrosion. The SHCC specimen showed superior performance compared to the reference specimen due to its multiple microcracking ability. SHCC proved to be an excellent alternative to brittle cementitious materials when corrosion induced cracking of the cover is a concern.