New mortars fabricated by electrostatic dry deposition of nano and microsilica additions: Enhanced properties

This work reports on the preparation and characterization of cement-based materials with additions of nano and micrometric silica. Their microstructure, mechanical properties and resistance to penetration of aggressive agents were studied. Mixtures of cement pastes and mortars with different percentages of nano and microsilica additions were prepared, with such additions being electrostatically incorporated into all cases in the anhydrous cement particles before the mixing process. The samples were characterized by the following experimental techniques: thermogravimetric analysis/differential thermal analysis (TGA/DTA), compressive strength tests, determination of the chloride migration coefficient, scanning electron microscopy (SEM), electrical resistivity measurement and mercury intrusion porosimetry (MIP). A relevant improvement in the mechanical and durable properties of the additivated samples when compared with the reference material was obtained.