Fig. 15
Crack width-dependent healing behaviour. (Healing efficiency as a function of normalized crack width. Normalization convention follows that of Fig. 14)a CaCO3 precipitation intensity across normalized crack width and length, highlighting preferential deposition near the crack tip and along narrow pathways. Precipitation is diffusion-limited and decreases significantly with increasing crack width and distance from the crack mouth. (b) Healing efficiency (% sealed width) estimated for different crack width bins at 12, 24, and 48 h. The model predicts highest healing efficiency (> 90%) in narrow cracks (0.1–0.3 mm), moderate sealing (65–78%) in mid-sized cracks (0.3–0.7 mm), and limited closure (< 50%) in wider cracks (> 0.7 mm). These results confirm the nonlinear, size-dependent nature of self-healing under MICCP conditions.
