Influence of Nano-SiO2 Addition on Microstructure and Mechanical Properties of Cement Mortars for Ferrocement

Because of their unique physical and chemical properties, nanoparticles have been gaining increasing attention and have been used in many fields to fabricate new materials with novel functions. If nanoparticles are integrated with cement-based building materials, the new materials might possess some outstanding properties. Ferrocement is a type of thin-wall reinforced concrete commonly constructed of hydraulic cement mortar reinforced with closely spaced layers of continuous and relatively small-sized wire mesh. The low level of technical skill required to make ferrocement and the ready availability of its materials make ferrocement suitable for a wide variety of applications. This study investigates the mechanical properties (compressive and flexural strengths) and microstructural properties (as determined by scanning electron microscopy) of the interfacial transition zone between cement pastes and aggregates of mortars applicable for the casting of thin ferrocement elements combining with nanosilica. Study parameters include the ratio of nanosilica to cement in ordinary portland cement mortar mixtures (including 1%, 2%, and 3%) and the water-to-binder ratio (including 035 and 0.4). The results show that cement mortars containing nanoparticles have a reasonably higher strength and denser interfacial transition zone than do ordinary portland cement ferrocement mortars, while the flowability of mortars with and without nanoparticles is considered equal.