Strength and Corrosion Protection of Silica Fume Concrete Containing Fly Ash or Calcium Nitrite Inhibitor or Both
P. Montes and I W. Bremner
Appears on pages(s):
calcium nitrite-based corrosion inhibitor;
compressive strength; corrosion current density; cracked concrete; fly ash; high performance concrete; water-to-cement ratio
This paper presents a study on the effects of fly ash and calcium nitrite based corrosion inhibitor (CNI) on the compressive strength and corrosion process of steel rein-forcing bars in high-performance concrete. A 34 full factorial design was developed considering water-to-cement ratio, fly ash percent, CNI dosage and cracked condition in a concrete made with silica fume blended cement. Small-scale concrete slabs containing steel reinforcement were cast in concrete with a cover depth of 20 mm. The slabs were subjected to both natural and simulated marine environments with two cycles of wetting and drying per day. Compressive strength of the concrete was determined at 28 days and at one-year. The corrosion activity was monitored on a regular basis using the linear polarization resistance technique. The results show a non-detrimental effect of CNI on corrosion of specimens containing fly ash and silica fume. CNI alone has, in general, no significant effect in decreasing corrosion; however, the crack width strongly affects the corrosion process.