GB601458A - Improvements in apparatus for testing concrete - Google Patents

Abstract

601,458. Testing physical qualities of concrete. FORSSELL, C. A. April 13, 1945, No. 9316. [Class 106 (ii)] Concrete is tested under compression by subjectiiig samples to opposed zonal loads instead of evenly distributed loads over the whole of the opposed surfaces. As shown, an untreated, non-machined sample 1 is compressed between opposed narrow fillets 4, 5 of wood fibre or other porous material retained respectively in grooves in a girder 17 secured to a member 10 resting on a girder 11, and in a girder 20 retained in pivotal contact with a short shaft 21 or a ball by means of springs 24. Supports 18 comprising casings in which are spring-loaded pistons, and a stop 32 on the girder 17 facilitate initial positioning of the sample. The springs 24 are attached at their upper ends to a support 22 shaped to accommodate the shaft 21 and secured to a cross-girder member 12 slidable on screws 13 secured to the bottom girder 11. Pressure is applied to the sample 1 by turning nuts 14 on the screws 13 to force down the girder 12, the nuts being geared together for simultaneous movement. A plate 15 ensures upward movement of the girder 12 when the nuts 14 are released. Instead of the pivotal arrangement 20, 21, 22, a plate carrying the fillet 5 is provided with a cross-plate at its upper edge which is rounded to bear on the flat face of the upper pressing-member ; further, the resilient supports 18 may be replaced by wedges of compressible material.