Title : EFFECT OF CRACKING ON CHLORIDE INDUCED CORROSION OF REINFORCEMENT BARS IN CONCRETE
Authors : Bhaskar Sangoju(1), Ravindra Gettu(2), Bharatkumar, B.H.(1), Ramanjaneyulu, K.(1) and Nagesh R. Iyer(1)
Publication : 13th – 16th February 2013
Volume :
Pages : 8-Jan
Price : 250
Abstract : Concrete generally contains micro-cracks that are formed prior (under service load) to corrosion initiation of the reinforcement bars, these have a great impact on the durability of concrete structures. The paper discusses the results of laboratory studies on accelerated chloride induced corrosion of rebars in cracked OPC (ordinary portland cement) and PPC (portland pozzolana cement) concretes. The effect of PCE SP (polycarboxylate ether based superplasticizer) and CNI (calcium nitrite inhibitor) admixtures on corrosion of rebar is also investigated. The effect of cracking on corrosion performance is studied by using U-shaped RC specimens. These specimens were cast with w/c of 0.47; high yield strength deformed bar of 12 mm diameter with 20 mm clear cover and subjected to accelerated corrosion; submerged in 3.5% NaCl solution and subjected to 10V constant anodic potential for specified time durations. Visual observations, in the initial stages of accelerated corrosion, indicated uniform corrosion in uncracked specimens and localised corrosion in pre-cracked specimens. Accelerated corrosion test and gravimetric weight loss results reveal that concrete with PCE SP performed well when compared to control and concrete with CNI.