LAUSR

Abstract Capsule-based self-healing materials are a promising solution for maintaining the mechanical properties and durability performance of concrete structures. To assess the efficiency of capsule-based self-healing cementitious material, analytical models considering the effect of the capsule shell thickness were derived for three common capsule shapes: sphere (SPH), cylinder (CYL), and a cylinder with spherical tips (CST). A numerical simulation method was used to validate the proposed analytical models. A parametric study was conducted to investigate the effect of the capsule diameter, aspect ratio, and shell thickness on the self-healing efficiency. Simplified analytical models were derived to calculate the capsule diameter, aspect ratio, and shell thickness for the shape design and manufacturing of the capsule. The results of this study show that: (1) the self-healing efficiency is proportional to the diameter of the capsule; (2) the self-healing efficiency increases approximately linearly with an increase in the aspect ratio for CYL and CST capsules; (3) the self-healing efficiency may be greatly over-estimated without considering the shell thickness, especially for spherical capsules.