GB497593A - Means for testing the proportions of concrete - Google Patents

Abstract

497,593. Analysing concrete. WINGET, Ltd., and STANCLIFFE, C. W. June 21, 1937, No. 17229. [Class 82 (ii)] [Also in Group V] A method for the analysis of concrete to enable the proportions of the constituents to be determined comprises washing a sample of the concrete before hardening through a series of sieves of successively decreasing size of mesh so as to separate the sample into portions consisting of cement, sand or fine aggregate, and one or more grades of coarser aggregate respectively. In the apparatus shown in Fig. 1, graded sieves 1, 2, 3 are supported by a cradle 4, and the whole suspended by a spring 8, within a. container 6. A known quantity of cement is placed on the top sieve and the container filled with a known weight of water. The cradle 4 is agitated so that the grades become separated on the sieves and the cement passes through. The proportions may be estimated by weight or volume. The container may be of glass or transparent material or may comprise a glass window, and may be supported from the balance 5 or from a stand or may rest on the ground. Means may be provided for raising the sieves above water for weighing purposes. In the apparatus shown in Fig. 2 the sample of concrete is introduced into the inner sieve through the chamber 20 and the cover 22 is replaced. The sieves are rotated by the crank 26. After separation the grades are dried and weighed. They may be removed by means of the plugs 16, 17, 18, 19. The fine sand which has passed through the finest sieve may be separated by further washing. The bearing 25 is such as to allow substantially universal movement of the sieves.' Either form may be arranged as a battery of units.