THE need for a method of estimating the strength of concrete suitable for use in the field has long been evident. The usual method of control adopted is to make cubes periodically on a run of mixer sample and send these away to a laboratory for testing in the usual manner. In a large number of cases, however, this is impracticable if only on the ground of expense, and the only guide to the quality of the concrete is that of visual inspection. J.F. Williams
THE problem with cracking in reinforced concrete is to eliminate the formation of cracks wherever possible and to distribute the cracking that does occur so that the individual cracks are not serious. F.G. Thomas
The above report, which was drawn up in 1918 by the Science Committee of the Concrete Institute, has now been withdrawn from the list of publications of the Institution. In British Standard Specification No. 560/1934 the standard symbols to be used in structural engineering are printed on pages 25, 26 and 27. The few cases where this Institution uses symbols or abbreviations which vary from those contained in the British Standard Specification, are set out in a note at the foot of page 27 of the Specification.