%0 Journal Article
%T Experimental and Empirical Time to Corrosion of Reinforced Concrete Structures under Different Curing Conditions
%A Ahmed A. Abouhussien
%A Assem A. A. Hassan
%J Advances in Civil Engineering
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/595743
%X Reinforced concrete structures, especially those in marine environments, are commonly subjected to high concentrations of chlorides, which eventually leads to corrosion of the embedded reinforcing steel. The total time to corrosion of such structures may be divided into three stages: corrosion initiation, cracking, and damage periods. This paper evaluates, both empirically and experimentally, the expected time to corrosion of reinforced concrete structures. The tested reinforced concrete samples were subjected to ten alternative curing techniques, including hot, cold, and normal temperatures, prior to testing. The corrosion initiation, cracking, and damage periods in this investigation were experimentally monitored by an accelerated corrosion test performed on reinforced concrete samples. Alternatively, the corrosion initiation time for counterpart samples was empirically predicted using Fick¡¯s second law of diffusion for comparison. The results showed that the corrosion initiation periods obtained experimentally were comparable to those obtained empirically. The corrosion initiation was found to occur at the first jump of the current measurement in the accelerated corrosion test which matched the half-cell potential reading of around £¿350£¿mV. 1. Introduction Reinforced concrete in severe environments, such as that subjected to high percentages of chlorides, is deteriorating at a quick rate and requires special design consideration to extend its service life. The most critical factor for this deterioration is the corrosion of embedded reinforcing steel [1]. The corrosion requires the chlorides from deicing salts, groundwater, or seawater to penetrate the concrete cover and reach the reinforcing steel. Once the percentage of the chloride around the steel bar exceeds the threshold needed for corrosion initiation, the corrosion starts and is then followed by propagation through steel bars, which eventually leads to a mass loss and destruction of the concrete cover. Chloride permeability is a significant property of the concrete representing its resistance to chloride ingress. This property directly affects the time for chlorides to reach the reinforcing bars and, consequently, the corrosion initiation time. Most of the models used for corrosion prediction [2, 3] account for the resistance of concrete to chlorides. Concrete with low permeability and dense microstructure proved to extend the time needed for corrosion to occur [4]. In fact, the total time to corrosion for reinforced concrete structures can be increased using high performance or less permeable
%U http://www.hindawi.com/journals/ace/2014/595743/