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Abstract
This paper describes a method for the interpretation of test results which makes it possible to estimate concrete cube strength from cores of various diameters with suitable confidence levels. To this end, 1,270 results of compression tests carried out on cubes with 150 mm sides, on typical small and micro-cores (70, 45 and 28 mm in diameter, respectively), have been elaborated with the aid of statistical methods, which can also be used for different types of test. The laws of correlation between cube strength and the strength values obtained from the different diameter cores are determined and discussed. The relationship expressing the lower confidence limits for future individual observations are developed, compared with one another in relation to the influence of core diameters, and proposed for thein situ estimate of cube strength.[PUBLICATION ABSTRACT]