Diffusion characteristics of OPC concrete of various grades under accelerated test conditions

Concrete durability mainly depends on the diffusion characteristics of concrete. Chloride ion diffusion is one of the main parameters affecting the durability of Reinforced Concrete Structures. The chloride ion penetration is determined under accelerated diffusion test condition with 12 V (Norwegian method). Depending upon the concrete quality, the diffusion test duration will vary. Generally, high grade concrete will have longer test duration as compared to lower grade concrete. In this paper, OPC concrete of M30, M40, M50, M60 and M75 grades were studied for diffusion properties under different voltages 12, 20, 30, 40, 50 and 60 V. A comparative study was made with standard Rapid Chloride Permeability Test with respective voltages. It has been observed that chloride profile and diffusion coefficient were high in low grade OPC concrete and low for high grade concrete. Minimum test duration was observed at higher voltages. With the increased voltage, the chloride profile and diffusion coefficient were found to be high.