Smart Self-Healing Concrete
Concrete is the second most popular material on earth after water. The relatively low tensile strength of concrete is the reason behind crack formation of concrete infrastructures under physical stress or heavy loadings. Cracks can impair the durability and lifetime of concrete as they provide an easy passage for the transportation of liquids and gasses that potentially contain harmful substances that can attack the concrete and ultimately cause the reinforcement corrosion. Preventing cracks propagation in concrete structures by designing self-healing and self-repairing mechanism is a promising approach in increasing the useful life of a concrete structure and reducing costs associated with maintenance and repair of concrete.
The aim of the project is to develop self-healing additives which can heal concrete structures by filling up the pores and cracks when these are formed in the concrete material based on encapsulation methodology. In this approach healing agents are isolated and encapsulated in breakable capsules (spherical or cylindrical) and incorporated in the concrete mix. The stress fields associated with propagating cracks can break these capsules releasing the healing agents which then react to form a glue that hardens and seals the crack at the place where they are needed.
Outcomes and Benefits
Preservation of vital concrete-based infrastructure and elongation of the service-life of an infrastructure
Self-healing of nascent fractures by the triggered release of healing agent from breakable micro-capsules imbedded within concrete component
Detection of imminent failure of concrete structures, crack density and propagation rates by the use of embedded stress sensors
Prevention from personal injury through structure collapse and associated disruption to our daily lives
Reduction in hidden societal costs such as loss in productivity due to unavailability of buildings, traffic jams, etc.
Allow the use of less cement in concrete construction thereby adding to the global effort for CO2emission reduction.
Dr. Shima Taheri (Macquarie University Research Fellow)