Title : CORROSION INHIBITION IN FLY ASH BASED PORTLAND POZZOLANA AND ORDINARY PORTLAND CEMENT CONCRETES
Authors : Bhaskar Sangoju Ravindra Gettu and B.H.Bharatkumar
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Price : 250
Abstract : The paper discusses the results of laboratory studies on the chloride induced corrosion of rebars in cracked OPC (ordinary portland cement) and PPC (portland pozzolana cement) concretes. The mechanical and durability parameters, as well as the behaviour of the reinforcement subjected to accelerated corrosion, were investigated. The effect of crack width on corrosion was studied on U-shaped specimens, with surface crack widths of 0.2 mm and 0.4 mm, subjected to impressed voltage and submerged in 3.5% NaCl solution. It was observed that the durability parameters such as RCPT (Rapid chloride permeability test) charge passed and chloride diffusion coefficient of PPC concrete were significantly lower than that of OPC concrete, and the resistivity was higher. Visual observations and recorded corrosion current data on U-shaped specimens also indicate that the corrosion process was faster and corrosion current was more in the case of OPC concretes. The corrosion-induced crack widths of PPC concretes were much lower than those of the corresponding OPC concretes. At the end of the exposure period, the gravimetric weight loss of rebars in OPC and PPC concretes were determined; the weight loss PPC concrete was lower than that of the corresponding OPC concrete. The relative service life (in terms of corrosion initiation period), of PPC concrete is more than twice to that of the service life of corresponding OPC concretes.