THE IMPORTANCE OF CORRECT TESTING TECHNIQUES FOR CONCRETE SPECIMENS

The acceptance of concrete used in construction usually involves testing of concrete cubes made and cured in a standard fashion, which are required to meet certain minimum strength criteria. On those relatively infrequent occasions when cube strength falls short of the specified strength, a possible course of action is to extract drilled cores from the structure for testing. A final decision is then made on the basis of these results. Unfortunately, core strength testing is not a simple matter, and interpretation of the results is often a taxing problem, especially if core strengths appear to fail the strength criteria. On these occasions, incorrect or inadequate testing techniques are sometimes suggested as a possible reason. However, this is seldom considered a valid factor, particularly when the actual testing is conducted by an independent laboratory. A recent case history illustrates just how serious the implication of poor testing procedures can be and how complacency with our proficiency in testing concrete cannot be justified.