Effects of calcium nitrate-based corrosion inhibitor and fly ash on compressive strength of high-performance concrete

This paper presents initial results from an extensive study of the effect of calcium nitrite-based corrosion inhibitor (CNI) and fly ash on the properties of high-performance concrete (HPC). A 3³ full factorial design was developed to evaluate the influence of water-cement ratio (w/c), CNI, and fly ash on the compressive strength of concrete. Experimental data were analyzed using a three-way analysis of variance (ANOVA). The study found, as demonstrated by previous studies, that when fly ash was used to replace portland cement in a concrete mixture containing silica fume, the 28-day compressive strength decreased. This effect is more pronounced as the w/c decreases from 0.45 to 0.29. At a w/c of 0.45, only a small reduction in strength is noted when up to 40% of the cement is replaced with fly ash, whether CNI is used or not. When CNI is added to a concrete mixture with or without fly ash, it does not adversely affect the compressive strength.