Assessment of a cracked reinforced concrete supporting structure for a converter in a steel melting shop through non-destructive testing and a statistical approach – a case study

Abstract

The subject of this paper is the occurrence of cracks and other types of damage, such as delamination of the reinforcement cover, carbonation, porosity, etc, which have occurred in a reinforced concrete supporting structure for a converter in a steel melting shop in India. The structure consists of two thick reinforced concrete walls on which the converter rests. Converters are used in a steel melting shop for blowing oxygen through hot metal and steel is produced through a reaction with carbon, silicon, phosphorus, sulphur, etc. A scientific review of the existing non-destructive test methods is carried out with reference to this case study and critical features of the testing process are described, which will help site engineers to correctly devise the test sequence and analysis procedure for assessment of the structures in specific critical conditions. Crack depth is estimated by analysing test results based on the ultrasonic pulse velocity. The paper explains how appropriate selection of the method and basic parameters is essential for estimating the most accurate crack depth. Lack of understanding of the existing condition of the material of the structure may lead to an incorrect interpretation of the test results. Further to this, a simple statistical procedure is described to identify significant cracks without detailed testing. The repair methodology and its specific features are also discussed in this paper. This case study on the assessment of the converter supporting structure will help engineers to provide solutions for similar types of damaged structure found in industry.