Evaluation of concrete quality by nondestructive tests.

Most of concrete standards gave recommended criteria that deal with the concrete quality by assessment the hardened concrete that conformed to the compressive strength of concrete must be adopting in the design of structural concrete member based on the compressive strength grade. Evaluation of concrete relies on the acceptance or rejection of concrete test that is the function of the compressive strength in which depending on the method of tests and the evaluation of the test results. In the present research, different nondestructive concrete tests such as ultrasonic pulse velocity and Schmidt hammer are adopted to investigated the compressive strength of concrete and discussed the important roles of evaluations of concrete test results with the acceptance and significance factors that impact on assessment the test procedure. The parameters that adopted are the concrete compressive strength as 30 and 35 MPa that tested at 7 and 28 days. Test results showed that the higher recorded velocity indicated that the concrete is more uniformity, less voids and denser. Schmidt test gave compressive strength more than the required design strength so that it is better to use reduction factor for this type of test that can be recommended to evaluate the concrete quality in situ. [ABSTRACT FROM AUTHOR]