Influence of Hydrated Lime Addition on the Self-Healing Capability of High-Volume Fly Ash Incorporated Cementitious Composites

This paper comprehensively studies the influence of hydrated lime usage on the repeatability and pervasiveness of the self-healing mechanism in engineered cementitious composites (ECC) incorporating high-volume fly ash (HVFA). Repeatability of self-healing was evaluated by repeatedly preloading the specimens up to 70% of their original deformation capacities at the end of each specified cyclic wet/dry exposure. Resonant frequency (RF) and rapid chloride permeability tests (RCPT) were used to assess the extent of deterioration. Crack characteristics were also presented to account for the changes observed in cracks throughout the RF tests. To monitor the pervasiveness of self-healing, RF measurements were recorded from both the top and middle portions of the specimens. Experimental results strongly suggest that the self-healing mechanism in cementitious composites can be made far more repeatable and pervasive with the addition of hydrated lime to the HVFA-ECC mixtures; this can have a significant impact on the development of smart sustainable infrastructures with highly robust self-healing capabilities.