The effects of age, cement content, and healing time on the self-healing ability of high-strength concrete

Our study assessed the self-healing process in high cement content, low water-to-binder ratio composites. Two different compositions were aged 2 and 20 months. Mechanically induced cracks up to 800 µm wide were analysed by an automated method based on high optical resolution scanning and computer image processing. For composites aged for 2 and 20 months, the maximum detected width of healed cracks was 460 µm and 388 µm, respectively. The healing process exhibited localized variability and was affected by crushed material in cracks. Crack width analysis coupled with microscopy and EDS indicated that a dense cement matrix may reduce self-healing efficiency.