Non destructive testing of concrete in structures

Abstract

The most common test result at present in use for the control of concrete quality in building and civil engineering projects is the standard crushing strength. Occasionally, the test specimens are broken in flexure and tension. In the United Kingdom and several other European countries the specimen is a 152mm cube, while in North America the standard compression test is a 152 x 305 mm cylinder. The crushing test has been used for many years in specifications as a performance measurement of concrete strength, and was included as a recommendation for concrete testing as early as the R.I.B.A. (Royal Institute of British Architects) Report of 1911. This test has served a most useful purpose since it combines in a single test a measure of performance which is related empirically to many of the desirable properties of concrete but it must always be appreciated that it does not measure any fundamental property of concrete and it is arguable whether it should be regarded as a universal assessment of quality without question. Understandably the codifiers selected that test since it was the time-honoured standard by which concrete was judged.