ABSTRACT
Nowadays, ageing of existing concrete structures exposed to highly aggressive environments is one the highest concerns for the construction industry. In this context, developing sustainable, efficient and secure technologies for the repair and maintenance of such structures rises as a challenge to assure their service life. In present paper, a noninvasive repair method, based on the application of colloidal nanosilica on the concrete surface, is proposed. Two mechanisms to force the nanosilica penetration have been considered: capillary suction and migration. The ability of colloidal nanosilica to consolidate the cementitious matrix has been confirmed; nanosilica promotes the decrease of capillary pores not only filling the pores but also interacting chemically with the substrate to form new gels, which seem to evolve with time in presence of the appropriate humidity conditions.
