Self-healing concrete can repair itself by closing micro-cracks and thus protect itself from ingress of deleterious gasses and liquids that can affect its durability. Many self-healing concepts have been developed in the recent years which target on the recovery of water tightness after cracking. Among those systems, the bio-based healing agents have shown promising results regarding the crack sealing performance. This paper studies the crack sealing efficiency of bio-based healing mortar with expanded clay particles. The investigation of sealing performance is conducted through experimental and computational approaches. Image processing and crack permeability test results are compared with results obtained by computer simulations. The study reveals that the experimental approaches might overestimate the crack closure percentage, while the computer simulation mostly underestimates the crack sealing. Finally, recommendations are given to improve the results obtained by both methodologies.