Condition Assessment of 30 Years Old Overhead RCC Reservoir

Concrete is considered as a durable material but it is still potentially vulnerable to deterioration, unless certain precautions are taken. Life enhancement of distressed concrete structures depend on number of factors such as design, detailing, materials used in the original construction, quality control, environment as well as periodic inspection and regular maintenance. The assessment of concrete structures consists of not only evaluation of the present condition but also prediction of the cause of deterioration and its residual life. Hence, it is essential to have accurate assessment of physical, chemical and electro-chemical properties to enhance the existing life of the structure. If the cause of deterioration is predicted and a proper assessment of the structure is made, it may be economically feasible to repair the distressed structure and prolong its life. Number of tests need to be carried out to assess the extent of distress and to estimate the quality/strength of concrete, before taking up any repair measures. These tests can be of either Non Destructive Type (NDT) or Partially Destructive Type (PDT). This paper discusses a case study, the assessment of 30 years old overhead Reinforced Cement Concrete (RCC) reservoir by NDT and PDT methods. The main aim of the paper is to highlight the importance and significance of different test methods employed to assess the present condition of RCC structure. A rational and systematic approach for the interpretation of test results based on NDT and PDT is presented for arriving at an economical repair procedure and rehabilitation measures. Necessary repair measures are suggested to enhance the service life of the structure.