Performance Evaluation of Sodium Nitrite Corrosion Inhibitor in Self Compacting Concrete

摘要

A kind of special concrete known for its flowing property and the mixture affixes under its self-weight. Henceforth under congested circumstance it obviates the difficulty of placing concrete moreover reducing the time in setting up large sections meanwhile affording increased strength and commanding durability characteristics than standard concrete. The major consequence facing all around is that durability concern with respect to corrosion of steel. The premature failures in concrete are caused due to this corrosion of steel. To improve a service life of concrete, corrosion inhibitors have been used as effective measures to inhibit corrosion. But there are numerous inhibitors were exists in the market. Only Sodium Nitrite (SN) has proven corrosion inhibiting capabilities simultaneously refine the mechanical properties of concrete. Therefore the presence of sodium nitrate in the self compacting concrete as the corrosion inhibiting admixture, the strength and corrosion resisting properties were studied by the dosage added 0%, 1%, 2%, 3%, 4% and 5%, by the weight of cement. Mix design for M25 grade of concrete according to BIS method (IS 10262:2009). Cement is replaced with consistent percentage of fly ash (40%). Then the standard concrete mix proportions were modified into SCC properties as per EFNARC specifications and different trail mixes were done. The investigation on the properties of self compacting concrete in spite of the effect of corrosion inhibiting admixture is done on the trial basis. The effect of Corrosion inhibiting admixture (a sodium nitrate based inhibitor) along with the properties of fresh concrete and the hardened concrete are determined. From the results it is proven that the self compacting concrete increases the strength of the concrete with accretion of inhibitor (sodium nitrite). Ultimately it was concluded that the compressive strength of cubes at 3% of sodium nitrite was increased strength by 8.8% in comparison with standard self compacting concrete (SN0) mix.