Question

Can non-destructive tests give an absolute measure of strength? Discuss

Answer 1

Non destructive testing is generally carried out for concrete members . The sample used for non destructive testing can be reused for service .

Non destructive testing may not give an absolute measure of strength. For example methods like Rebound hammer test which is used for non destructive testing of concrete , in this method plunger is pressed against the surface of the concrete, energy rebounded by concrete gives idea of its compressive strength. But it gives idea about strength of surface concrete only and doesn't give idea of strength of interior portion of concrete. Also this method give different result when plunger is pressed against mortor or when pressed against aggregates. Similarly other methods have certain disadvantages too. Thus we cannot completely relay on non destructive testing for predicting strength of member.