Process of In-Place Evaluation of Concrete Strength

Abstract

In-place test methods are available that can be used as alternatives to testing field-cured specimens to evaluate concrete strength in a structure. However, in-place test results do not represent the compressive strength of concrete directly but are empirically correlated to the compressive strength. Therefore, to use in-place test methods to estimate the strength of concrete, a preestablished relationship is required between the in-place test results and standard cylinder test results. In addition, a statistically based procedure is needed for a reliable estimate of concrete strength based on the strength relationship and in-place test results. This paper describes the statistical framework for developing the strength relationship and provides a step-by-step procedure to evaluate the characteristic compressive strength of concrete from in-place test results. Pullout test data are used to illustrate the use of these computational procedures.