Edurne Erkizia

An Innovative Self-Healing System in Ultra-high Strength Concrete Under Freeze-Thaw Cycles

The development of cementitious materials with self-healing properties is currently a very active research line in order to increase the service life of structures and reduce the costs associated to maintenance and repair. A combination of silica microcapsules containing an epoxy sealing compound and nanosilica particles functionalized with amine groups has been developed to confer self-healing properties to an ultra-high performance concrete. The durability of the self-healing system under severe climatic conditions is considered in this work. Cylindrical concrete specimens were made with and without the self-healing additions. After a curing time of 28 days, micro-cracks with a controlled width were created in the specimens that were subsequently subjected to a freeze-thaw test consisting of four cycles per day between −20 and +20 °C. The results from capillary water absorption test after 150 cycles confirm the efficiency of the sealing system even under the aggressive conditions considered in this study.