Modeling of self-healing efficiency for cracks due to unhydrated cement nuclei in hardened cement paste

Nuclei of unhydrated cement particles left in hardened cement paste after maturation can provide self-healing capability to micro-cracked matrix under favorable conditions. In this present study, a model study is conducted to characterize the influence of hydration reaction of the unhydrated cement nuclei on self-healing efficiency of cracks in hardened cement paste. Based on two different cracking modes of unhydrated cement nuclei, i.e., the splitting crack mode and the dome-like crack mode, the mathematical expressions on the self-healing efficiency are presented from the viewpoint of geometrical probability. Recurring to a generalized hydration reaction model of cement particles, the self-healing efficiency model quantitatively consider the influence of the volume fraction, particle size distribution and cracking modes of unhydrated cement nuclei randomly distributed in hardened cement paste.