Performance specifications for concrete using the durability index approach

The noticeable shift towards performance specifications for durability calls for the adoption of reproducible, reliable and quick measures of transport parameters that are known to affect concrete durability. In addition, the ability to assess these parameters in actual construction, appropriate criteria for limiting values for durability parameters, and penalties or incentives for failing or achieving the necessary durability requirements, are equally important. The "Durability Index" approach has been developed in South Africa to provide a basis for specifying performance for durability of concrete. Three tests that primarily measure the transport properties of cover zone concrete are used to generate performance indicators. This approach has been successfully used in practice in South Africa, and could have a good potential for application in the Indian concrete industry. This paper describes briefly the tests followed under the durability index approach, and how the results from these tests could be used to set up performance criteria that can be used for specifying concrete quality to ensure long-term performance.