Assessment of reinforced concrete sewer after long service: a case study

Assessment of the reinforced concrete shells of a sewer after two decades of service is presented. The methods used to investigate the sewer structure are described and the criteria for evaluating its safety are given. As part of the assessment and analysis laboratory tests of the concrete were carried on core samples taken from the shells. Concrete strength, carbonation, water permeability and leaching depth were checked. The degree of corrosion of the reinforcing steel and loss of reinforcement cover were also examined. The material tests’ results were then used in a numerical analysis of the stress in the shells that checked level of the structural safety. Based on the experimental and numerical results the approximate life cycle was estimated at another 55 years.