Statistical relation between cylinder modified cube and beam strength of plain concrete

The relationship between the cylinder, modified cube, and beam strength of plain concrete is determined statisti cally for concrete having varying strengths and made from different mixes. The aggregates used were the same for all specimens. The results presented are based on over 1,400 indi.vidual static tests involving concrete of different strengths and ages. Beams having 6 by 6-in. cross section were tested on two different span lengths, 60 in. and 18 in. Modified cube tests were conducted on the broken pieces obtained from these beam tests. Cylinders tested were standard 6 by 12-in. size. The information obtained from these tests has been presented in five graphs which have been fitted with "least squares" curves. For each curve the coefficient of correla tion and the standard error of estimate is given