A self-healing cementitious composite using oil core/silica gel shell microcapsules

This paper presents work toward the development of a new family of self-healing materials that hold promise for “crack-free” concrete or other cementitious composites. This innovative system features the design of microcapsules with oil core and silica gel shell. Methylmethacrylate monomer and triethylborane were selected as the healing agent and the catalyst, i.e. oil core phases in the system. They were microencapsulated, respectively, through an interfacial self-assembly process and sol–gel reaction. Then the microcapsules were dispersed in fresh cement mortar along with carbon microfibers. The self-healing effect was evaluated using permeability measurements along with a fatigue test under uniaxial compression cyclic loading and further confirmed by surface analytical tools including optical microscope and field emission scanning electron microscope coupled with energy-dispersive X-ray analyzer (FESEM/EDX).