Bulletin Volume 3-27 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1916 Excerpt: ...28-day tests could be predicted from the 7-day tests of commercial or native sand mixtures with portland cement. A similar study upon portland cement is presented in this paper. The data upon 711 portland cements tested in tension in a 1:3 mix with standard Ottawa sand are embodied in this report and the accuracy of the constants thereby obtained are applied to 196 subsequent tests. The testing procedure employed throughout the investigation conforms with the standard requirements of the American Society for Testing Materials. The method of analysis of the data was that used and described in the bulletins previously issued from this station. For those readers who are not familiar with the "Statistical Method of Analysis of Data" the current "'The Prediction of the 28-day Breaking Strength of Mortars from their 7-day Results." Gowen, John W., Leavitt, H. Walter and Evans, W. S., Bulletin No. 10, pp. 1-32, 1925. standard texts may be consulted for a more extensive description of the methods used.2 The data upon 711 samples of cement are given in Figure 1 below. The average 7-day tensile strengths for each of the samples are plotted as abscissae and the corresponding 28-day tensile strengths are plotted as ordinates, using the upper left hand corner as the origin. 7-DOT TENSION "The methods of statistical analysis of data involving correlation are described in the following texts: G. Udney Yule, "Introduction to the Theory of Statistics," J. B. Lip pincott Co., Philadelphia. A. L. Bowley, "Elements of Statistics," P. S. King and Son, London. D. Caradog Jones, "A First Course in Statistics," G. Bell and Sons, Ltd., London. T. L. Kelley, "Statistical Method," MacMillan, New York. E. T. Whittaker an...