Fracture properties of nanosilica-based cement mortars monitored by acoustic emission

Use of nanoparticles in developing materials has gained recently recognition and is being applied in many fields. Specifically, such particles can lead to improving performance of building materials such as cement and concrete. This work focuses on reinforcing Portland cement type II with nano-silica and comparing the properties of the nano-modified material with those of plain cement-based material. Physical tests, as well as compressive and bending tests were conducted to assess the effect of the reinforcing nanoparticles and that of the mixture procedure on the performance. The results show a marginal deterioration in material properties compared to plain cement mortar, while, the acoustic emission monitoring revealed differences in fracture behavior due to the addition of the nanoparticles. Specimens with well-dispersed nano-silica exhibited stronger shear fracture characteristics than those without nano-reinforcement, which exhibited less acoustic activity. The results are interpreted and discussed taking into account the properties and the dispersion of nano-silica in the cement mortar.