The Tuscan Boracic "Soffioni" and their Development at Larderello Discussion on Dr. Ing. Alfredo Maz

Professor A. L. L. BAKER (Member of Council), proposing a vote of thanks to the lecturer, said it seemed to him, on looking at the tables, that the most significant results were that in beams having a factor of safety of about 1.5 against cracking, a factor of safety against failure of about 3 had been obtained fairly consistently. That seemed to be very satisfactory, because if prestressed work was carried out under factory conditions of control of concrete, it should be possible to maintain consistently a standard of concrete which would justify designing to a safety factor of 3. In the course of time, he hoped it would be possible to have such control of concreting in the field that working to a factor of safety of 3 would be justified.

An Ordinary General Meeting of the Institution of Structural Engincers was held at 11, Upper Belgrave Street, London, S.W.1, on Thursday, 28th June, 1951, at 5 p.m., Mr. J. E. Swindlehurst, O.H.E., M.A., M.I.C.E., M.1.Struct.E. (President) in the Chair.

The concrete control methods described in this paper, although not new in principle, originated in their particular form during the construction for the Sunderland and South Shields Water Company of a small reinforced concrete reservoir, and were later used on the construction for the same Company of barrel vault roofs to cover two existing service reservoirs. The paper therefore deals with concrete control as carried out' in these instances, with the implication that such methods may be directly applicable to other similar works. The title of the paper refers to "small works" but as the adjective is,of course, only relative, it may help to fix them on the scale of magnitude if, it is stated that the two structures respectively cost £45,000 and £20,000, and involved the placing of 1,600 cu. yd. and 600 cu. yd. of concrete. In each case the concrete was mixed in a 14/10 mixer. N.J. Ruffle