Nanomaterials in self-healing cementitious composites

The use of nanomaterials in cementitious mixtures has received growing interest in the last few decades owing to their ability to enhance a wide range of material properties, such as an increase in mechanical performance and the improvement in the self-healing capacity. The latter feature is highly important in order to increase a construction’s durability and service life as a cementitious material under tensile stress may exhibit cracking, endangering the durability once substances enter the crack and penetrate into the inner layers. Various mechanisms that contribute to the self-healing ability of cementitious materials are discussed, in addition to the influence of various nano-additions to obtain crack sealing or water tightness and/or to promote healing. These additives are able to contribute to crack healing in different ways. While reactive nano-particles are responsible for the production of materials inside the crack, inert nano-fillers act as nucleation sites for healing products to form. Finally, some future perspectives concerning the use of nanomaterials in self-healing cementitious composites are summarized. The use of nanomaterials is a promising path to obtain cementitious materials with the enhanced capabilities to either heal damage or at least promote a healing mechanism, in combination with other improved material characteristics.