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PERFORMANCE ASSESSMENT OF CALCIUM NITRITE BASED CORROSION INHIBITING ADMIXTURE IN REINFORCED CONCRETE
Journal
Indian Concrete Journal
ISSN
00194565
Date Issued
2022-04-01
Author(s)
Pattanaik, Suresh Chandra
Patro, Sanjaya Kumar
Das, Bitanjaya
Abstract
The durability of the reinforced concrete structures in the marine environment can be achieved by adding corrosion inhibitors in the concrete mix. Performances of concrete specimens were evaluated for control and having corrosion inhibiting admixtures of calcium nitrite at 30 % concentration of the active ingredient without induced corrosion environment. The various tests performed were concrete resistivity, rapid chloride permeability test (RCPT), compressive strength, and microscopic analysis of concrete specimens at normal exposure condition. The reinforced concrete specimens were prepared of M30 grade concrete with and without calcium nitrite based chemical admixture of varying dosages of 1 and 2 % by weight of cement. The corrosion probability was found low and negligible in concrete specimens with corrosion inhibiting admixtures as compared to control samples when tested for electrical resistivity. There was also marginal improvement in the 28-days compressive strength of samples having corrosion inhibiting admixture as compared to control samples. Alternatively, no such appreciable improvement was noticed in any samples made with corrosion inhibiting admixture for corrosion resistance while tested by RCPT. Thus, the RCPT result may mislead the performance of inhibiting admixtures to protect the corrosion in reinforced concrete. Moreover, the concrete resistivity test reveals the effectiveness of inhibiting admixture in corrosion prevention of reinforced concrete. Further, the microscopic study by petrographic examination disclosed that samples made with corrosion inhibiting admixture helped to reduce shrinkage cracks, reduces air voids and strong bond between aggregate-cement paste as compared to control sample.
Volume
96
Subjects