Self-Sealing Performance of Healing Agents via a Low and High Pressure Water Permeability Test with Active Crack Width Control

With the continued rise of the world population, it is important to focus on the sustainability of our building materials. Traditional reinforced concrete is prone to cracking and these cracks have a detrimental effect on the durability, thereby limiting the service life. Repair of the damage is often costly and if not done timely the structure needs to be replaced. Self-healing concrete has the capacity to repair its own cracks. The current study investigates two self-healing agents: an organic/inorganic hybrid admixture and bacterial pellets. The self-sealing performance of the two healing agents were compared with a reference mortar using a permeability setup, after cracking the specimens with an active crack width control technique. The performance of the organic/inorganic hybrid admixture was best after healing the mortar specimens for a month in submerged conditions. Nevertheless, all other series also had a significant sealing efficiency. In order to differentiate the results better and in order to test the stability of the healing products deposited in the crack at higher pressures, the specimens were also subjected to a high-pressure permeability test. Again the organic/inorganic hybrid admixture came best out of the comparison.