Capillary Flow Characteristics of an Autogenic and Autonomic Healing Agent for Self-Healing Concrete

Abstract

Capillary flow through discrete cracks is the main mechanism by which healing agents embedded in cementitious matrices travel to zones of damage to afford the host matrix a healing ability. However, the nature of the interaction between the healing agents in their fluid state and the host matrix is unknown and may limit the ability to predict the behavior and efficacy of self-healing systems. This study considered the capillary flow characteristics of a low-viscosity cyanoacrylate and ground granulated blast furnace slag in a water suspension using glass capillaries and channels formed from a range of concrete mixes. Both healing agents conformed closely to Poiseuille’s law and experienced increases in viscosity over the 40-min period that they were exposed to a cementitious environment. Numerical simulations of the capillary rise response of the healing agents in a discrete crack confirmed that the rate of damage and degree of saturation of the concrete element have a significant influence on the choice of healing agent in the design of self-healing systems.