Use of Nano Silica Sol for Performance Improvement of Marine Cement-Based Mortar

Nano silica sol is an aqueous solution containing colloidal nano-silica. From limited research in the literature, it has been reported to offer better effects on the cement-based materials compared with nano-silica powder, which is by far the most widely studied nano-material. In this research, the possible use of nano silica sol to improve the performance of marine cement-based mortar is investigated. The optimal type of nano silica sol among acidic, neutral, and alkaline pH is identified, followed by systematic experimentation of the flexural strength, compressive strength, chloride ion permeability, as well as Fourier-transform infrared (FTIR) spectrum and X-ray diffusion (XRD) pattern. It was found that alkaline nano silica sol outperformed acidic and neutral counterparts. Generally, the addition of nano silica sol increased the flexural and compressive strengths of marine mortar. Addition of 3% nano silica sol by volume of cement yielded remarkable effects, while further addition