Modelling Autogenous Self-Healing with Dissoluble Encapsulated Particles Using a Phase Field Approach

Abstract

In this paper, a modelling approach for autogenous self-healing is presented that is initially based on the healing potential of encapsulation of various cement particle fractions with time. The healing potential of a blended cementitious system will be provided that consists of original cementitious particles mixed with so-called Dissoluble Encapsulated Particles (DEPs). The self-healing principle of this system is based on a most basic healing concept, where the evolution of the healing material can be separated into the late hydration of DEPs and the carbonation of calcium hydroxide. In this regards, a phase-field model is presented that is based on thermodynamics and kinetics of the prevailing chemical reactions. The concept enables to predict the healing potential of DEPs inside a cement-based system and analyse the most dominant parameters affecting the microscopic and macroscopic properties of (re-)hydrated microstructure. For this, the liquid-solid interfaces of the dissolution and/or precipitation mechanism is considered as a continuous density field driven by a reaction equation. The results show the potential of the healing mechanism to bridge a certain crack width, and shows the ability of the proposed modelling approach for autogenous self-healing.