Daniel Lahmann, Wolf-Achim Kahl, Sylvia Ke?ler
Cement and Concrete Research 197 (2025): 107965
https://doi.org/10.1016/j.cemconres.2025.107965
Autogenous self-healing of cracked concrete remains a highly uncertain phenomenon in building practice, with the influence of the binder composition and curing time not yet fully understood. This study investigates self-healing of cracked concrete produced with CEM I, CEM II/A-LL and CEM III/A after 7 or 28 days of curing, aiming to model reactive transport and validate previous research. Healing efficiency generally decreased as crack width increased because flow rate scales with the third power of the crack width, while crack closure through CaCO3 precipitation increases only linearly. Rather than portlandite content of the binders, the results suggest that CaCO3 precipitation and thus healing efficiency is governed by portlandite availability and potential microstructural changes due to carbonation. Notably, young limestone and slag cement samples showed a significantly lower capability to self-heal than comparable Portland cement reference samples, highlighting the need to reassess autogenous self-healing in practical applications.
