NEW LYNN TEST.

Auckland Star, Volume LXVI, Issue 124, 28 May 1935, Page 9

NEW LYNN TEST.

REINFORCING BRICK.

USE OF STEEL TIES. GROUTING POURED IN SLOTS. A new system of reinforcing brick construction work with steel rods analogous to the reinforcement used in concrete for the purpose of withstanding earthquake shocks was demonstrated to a large gathering of local body representatives, civil engineers and architects at the works of the Cruni Brick, Tile and Pottery Co., Ltd., New Lynn, yesterday afternoon. The lion. E R. Davis, M.L.C., Mr. A. Harris, M.P.. Mr. H. G. R. Mason, M.P., Mr. A. W. Bishop, chairman of the Waitemata County Council, Mr. A. J. Koutley, chairman of the Glen Eden Town Board, and the Mayor of New Lynn, Mi-. George Lawson, were present at the tests. The principle adopted is comparatively simple, and follows the lines of the tierods used in concrete construction, yet it is stated to be quite new in brick manufacture and has been patented in New Zealand, the United States of America and England. The main factor is the use of slotted bricks through which steel tie-rods are threaded and cement grout is poured so as to ma tee the entire brick panel a reinforced whole. The slots in the bricks are fin wide, and steel bars gin thick are run through diagonally. The mortar grouting is then poured in. The advantage claimed for this form of construction is thot, although the bricks are bonded together with mortar in the usual way, tha steel rods ca7i be threaded through so as effectively to reinforce the wall panels. The tests performed yesterday wore carried out by Mr. Graham Bell, who informed the gathering that it was proposed to apply a load by means of a hydraulic jack to a series of brick panels about 4ft high and 3ft wide. These brick panels had been laid on 9in concrete foundations. The pressure would be steady, and quite a different thing from earthquake shocks, which were usually sudden and varying in intensity. The first test made by Mr. Bell was carried out on a common brick partition wall, built in the ordinary manner, and carefully laid. This panel stood 3 7-11 tons pressure before it fractured. The second test was made on a slotted brick partition laid in the normal manner. This broke under between two tons and two and a half tons pressure. A panel consisting of slotted bricks grouted right through •with mortar was then tried. In this test the whole panel lifted from the foundation without breaking, and Mr. Bell pointed out that the strength .vas not really tested. As in all cases, the pressure had been applied from behind the panels to the top of the partitions. A further test was then made of slotted bricks, reinforced with steel rods and grouted right through. At a pressure of about 7i tons this panel also broke away from its foundation, but the brickwork itself was unaffected by the force which had been exerted upon it, while the steel rods were £'11 found to bo intact. As additional tests, a piece of wall made from cottage brick, for comparison with the larger type of brick, was subjected to pressure, withstanding almost 1J tons. The same size slotted brick grouted with mortar withstood almost 2 l-i> tons, while a partition of slotted cottage brick, both grouted and reinforced, was lifted from its foundation at a pressure of just over three tons, the panel being undamaged.— (Ad.l