AMONGST the interesting developments expected in the Provence of Mozambique (Portuguese East Africa) is the completion of it works to produce Portland Cement at Lourenço, Marques. At the present time a £9,O00,000 loan to the Provence is being negotiated and irrigation and other works will benefit. To find cement on the site as it were is therefore a matter of interest. The factory itself is interesting in that of its kind it is probably the last word in up-to-date manufacture, and a high class cement is expected. The construction stage has now terminated and production is likely to commence this month. South African Correspondent
AT the General Meeting of the Institution, held on Thursday, the 21st February, the following paper was read by DR. E. H. SALMON:- I. That Euler’s limiting load merely implies passage from one type of stable equilibrium to another, and does not involve the failure of the column. (Quoted in "Popular Fallacies Explained and Corrected,” by A.S.E. Ackermann, BSc. Engineering), 3rd edition, p. 884, in the inverse form, from a review by L.N.G.F. in "Nature,” June 24, 1920.) E.H. Salmon
WHEN steel was first introduced into this and other countries, the study of corrosion problems in ferrous metals had not reached the importance that is attached to it today.
THE "Simplex" system of Concrete Piling was the first method of casting piles in "situ," and has been extensively used in all parts of the world.
ESTRACTS from Report of American Concrete Institute’s Committee on Treatment of Concrete Surfaces :- When reinforcing steel in exterior members is not back at least one full inch from the outside face of the concrete, moisture works its way in, causing it to rust. Eventually, this rusting if continued will spall off the concrete and cause an unsightly appearance, and may even in severe cases affect the strength of structure. Good design should never call for such sizes of hoops, spirals, stirrups, &C., as will necessitate steel within one inch of the surface, but sometimes due to careless placing the steel will be at or near the surface.
Sir,-I read with considerable interest the article in your issue of December, 1923, on Present Methods of Teaching, which was contributed by Mr. W. G. Sheppard in relation to a paper by Mr. H. H. Clapham, which was published in your November issue.
The Architect and Concrete. A theory is sometimes expressed that the use of reinforced concrete is detrimental to artistic architectural expression. This being a theory with which we do not agree we propose devoting certain of our pages each month to the illustration of examples of modern architecture in support of our contention that concrete may be made, in proper hands, as expressive of good design as any other material. To this end, on pages x. and xi., will be found illustrations of a Chinese newspaper printing and publishing office, and a modern factory in Liverpool, both, and especially the latter, of distinctly chaste design. The Man in the Street
PRESENT-DAY conditions imperatively ,demand efficiency,reached by economical means, in everything concerning building. Prices, as the rcsult of high wages and the scarcity of skilled labour, still rule above the normal. This necessity for care is felt as keenly in the matter of painting as in other branches. Painting is essentially a protective process, only secondarily a beautifying or decorative one. Paint, therefore, must be applied thoroughly, to secure complete covering and good adherence.
Insulating Pipes from Vibration and Deformation Pipes (gas, water and others) carried by bridges, sheathed tunnels or other metal structures commonly rest on stands or are suspended by means of stirrups. In neither case is there adequate insulation from the carrying structure, consequently the pipes are subjected to the influence of vibration, and, still more serious, to be disjointed owing to deformation of the carrying members. To mitigate both these accidents it is suggested that stirrups should he suspended by means of springs, and that in special cases a spiral spring should be interposed between the crown of the pipe and the structural member immediately above it. When pipes are carried in cradles, springs can be inserted in the rests to act as buffers or cushions. (Deutsche Bauzeitung, No. 58.)
THE progress made in reinforced concrete construction during the past twenty years has been so great that a knowledge of the principles of reinforced concrete design is now almost essential to every young structural engineer who has his career before him; the past ten years has seen a very valuable and extensive addition to the literature of the subject, but many students still have considerable difficulty in following the treatment usually given. Ewart S. Andrews
HOUSING is not a subject with which the Structural Engineer is generally concerned, but it is one which would benefit greatly by his attention. The principal object of this article is to present the case, from an engineering point of view, for the use of concrete for the present day building requirements, particularly in so far as the housing problem is concerned, and having regard to the shortage of bricks and skilled labour. Major W.H. Smith
II. Materials, Methods of Testing and Tests PORTLAND cement was used which passed the standard tests for specific gravity, fineness, soundness and time of setting. The specific gravity was 3.10. J. Singleton-Green
IN calculating the bending moments in a beam freely supported at the ends it is usual, when the loading is not symmetrical, first to calculate an end reaction. Many people do not realise that the calculations can be put in such a form that the complete bending moment and shear diagrams can be drawn without further calculation. W.A. Green