Effects of Calcium Nitrite-Based Corrosion Inhibitor and Fly Ash on Compressive Strength of High-Performance Concrete

Abstract

Calcium nitrate-based corrosion inhibitor is often added to concrete mixtures to provide corrosion protection to the steel reinforcement. This paper presents the 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 The authors developed a design to evaluate the influence of water-cement ratio (w/c), CNI, and fly ash on the compressive strength of concrete. A total of 27 mixtures were made of air-entrained low w/c concrete containing 8.2% silica fume, different amounts of fly ash, and with and without corrosion inhibitor. Results showed that when fly ash was used to replace Portland cement in a concrete mixture containing silica fume, the 28-day compressive strength decreased. These results confirm and replicate those found in earlier studies. The authors note that this effect is more pronounced as the w/c decreases from 0.45 to 0.29. When CNI is added to a concrete mixture with or without fly ash, it does not adversely affect the compressive strength.