Evaluation of current condition state of reinforced concrete structures exposed to severe environmental condition

Abstract

Deterioration of reinforced concrete structures arise due to corrosion of steel present in concrete which leads to structural failure. A number of techniques and methods are being followed and studied by various researchers to predict the service life of the reinforced concrete (RC) structures. Chlorides initiate the corrosion of embedded reinforcements, which not only produces signs of deterioration on the concrete surface, such as rusting, cracking and spalling, but also reduces the load-carrying capacity. This paper discusses service life prediction methods of RC structures exposed to severe environmental conditions. Several methods were used to predict the service life and current condition state of the existing structures. Based on the mathematical modeling, the corrosion process could be formulated by three stages. They are namely, the initiation time (tc), the de-passivation time (tp), and the corrosion propagation time (tcorr). The total service life of RC structures can be expressed as summation of these time periods. In addition, crack observation method based on visual observation on the samples and existing structures and Accelerated Corrosion Testing Method (ASTM) was carried out at the laboratory. To identify the diffusion coefficient of the samples, the Rapid Chloride Penetration Test (RCPT) was carried out at the laboratory. Current condition assessment of the existing concrete structures was evaluated by using nondestructive techniques. This paper briefly discusses the current status of RC structures deteriorated by chloride attack in the Galle area, experimental investigation results and numerical analysis of corrosion cracking.