Anodic corrosion inhibitors against chloride induced corrosion of concrete rebars

Abstract

The effect of anodic inhibitors [calcium nitrate Ca(NO 3 ) 2 , calcium nitrite Ca(NO 2 ) 2 and potassium nitrate NaNO 2 ] has been evaluated using cylinders with steel rebars exposed to the following environments: in the marine tidal zone, at roof top and in air of 38uC and 90% relative humidity for 4 years. The experiments showed that the half cell potentials were more negative than the visual inspections proved when anodic inhibitors are used. Inhibitor dosage on 3-4% of cement weight seems sufficient to protect the rebar against corrosion. Capillary absorption experiments showed that the concrete porosity was unaffected by the inhibitors. The concentration profiles of chloride, nitrite and nitrate were investigated with respect to leaching. However, it was difficult to find the background level of nitrite due to possible chemical alteration.

Inhibiters replacement of chilled water system in nuclear unit

“…As shown in Figure 4, the polarizability of anode was bigger than that of cathode after 20 days of immersion in NaNO 2 -Na 2 MoO 4 solution, illustrating that the corrosion process was controlled by the anodic process. It was because both NaNO 2 and Na 2 MoO 4 were anodic corrosion inhibitors (Stnor and Justnes, 2011), which could hinder the anodic corrosion process of B10 metal. The corrosion potential and current of B10 electrode became much lower after 35 days of immersion, meaning that the corrosion resistance performance of B10 metal had not been weakened greatly during the inhibitor replacement process.…”

The effect of the corrosion inhibition of steel bar and the property of salt adsorption to salt adsorption type epoxy resin

“…Reinforced concrete structures are subject to salt-induced deterioration such as cracking and spalling due to corrosion of the reinforcing bars in the concrete caused by the effects of salt from the marine environment, extraneous salt from anti-freezing agents sprayed during the winter, and intrinsic salt from the use of insufficiently cleaned sea sand [1][2][3][4]. Repair materials in which salt adsorbent or lithium nitrate is added to inorganic materials are used for repair against such salt damage [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”

Preparation and Electrochemical Characterization of Concrete Containing Microencapsulated Calcium Nitrate Corrosion Inhibitor

“…To release calcium nitrate from the microcapsules the microcapsule must be ruptured from a crack forming in the concrete matrix. This will initiate the corrosion inhibition process, as calcium nitrate will act as an anodic inhibitor against chloride-induced corrosion [5].…”