Influence of nano-silica and crack width on corrosion parameters of pre-cracked reinforced concrete beams

Abstract

This paper presents an experimental study on the durability of both sound and cracked reinforced concrete (RC) beam specimens. Using nano-silica (NS) can improve the durability properties of reinforced concrete. So, RC beams with three nano-silica percentages of 0 %, 1.5 %, and 3 % were prepared. In addition, to consider the effect of cracking on corrosion, crack widths between 0.1 mm and 0.5 mm, and cover depths of 30 mm and 45 mm were considered. All beam specimens were subjected to 5 % NaCl solution and monitored weekly for half-cell potentials (HCP). The presented results include the HCP evaluation and diffusion factor values in sound and cracked concrete beams exposed to chloride attack. The experimental results indicated that the chloride diffusion coefficient increases with extending crack width. Nano-silica improved the permeability characteristics of concrete, HCP and also diffusion factor values. Regressive models of the chloride diffusion factor and HCP values were proposed for influencing parameters, i.e., nano-silica and crack width with two different cover depths.