Robust evaluation of self-healing efficiency in cementitious materials - A review

During the last decade, self-healing of concrete has attracted so much attention in the research community as a promising tool toward more durable and sustainable infrastructures. Although various self-healing approaches have been vastly studied, employment of different assessment methods in these studies has made it difficult to compare the efficiency of various self-healing mechanisms. This paper presents a review of test methods which have been commonly utilized to assess the efficiency of self-healing mechanisms in concrete. Three broad categories of assessment methods are considered, namely visualization and determination, assessment of regained resistance and assessment of regained mechanical properties. Moreover, as a pathway toward standardized evaluation of self-healing mechanisms, various assessment techniques are evaluated against four proposed essential criteria - reliability, quality of results, operational considerations and in-situ applicability.