AGE OF CONCRETE

Greymouth Evening Star, 1 June 1928, Page 9

AGE OF CONCRETE

OUR NEW BUILDINGS. When Macaulay’s New Zealander gazes upon the modern concrete structure, will he, in his rediscovery, see in them something which we living in the wood cannot see for the trees? In other z words, will he see in them the beginning of a new civilisation? Our best ideas of civilisation in the past are gleaned from buildings left behind From them -we can judge, not only the general standard of life, but the outlook and ambitions of the peoples. The ancient Egyptian view of the relative value of this life and the next is made clear to us at once when we see the everlasting way in which their tombs and pyramids were built. We gather better the grandeur of the Roman Empire from some mighty fragment of a concrete vault than from any written description. Do the concrete buildings of the present day indicate a change in our civilisation ? Professor C. H .Reilly, writing in “John o’ London’s Weekly” thinks they do. * The last fifty years might well be called the Portland Cement Age, he says, although that material was discovered more than a hundred years ago by a Leeds engineer. Portland cement has done for us what Roman cement did for the Romans. It has made possible a new form of construction. The cement that, the Romans used, enabled them to vault over great halls, as big as our cathedrals, in solid concrete, sometimes twenty feet thick. It was the quick-setting property of their cement which made it possible for the Romans to build these vast , vaults of loose saijd, broken brick, and stone, all held together by cement, for that is all concrete is. When in the decline of the Empire the art of making this cement was Jost, these great vaults could no longer be built. For seven centuries men searched about to find a substitute for them, as strong and fireproof as they were, and finally they hit on the ribbed Gothic vault made up of small stones set in ordinary lime, mortar, and Gothic construction took its place. The discovery of Portland cement in the nineteenth century again made possible a strong concrete which would span from wall to wall in vaults or from girder to girder. But the nineteenth century was not an age of great originality in building methods, and except in the Catholic Cathedral at Westminster, where the great domes are in. concrete, no great vaults were erected in solid mass concrete as the Romans used. The method was probably too expensive in a commercial age even for churches, for it involved immensely thick and strong walls as well. The nineteenth century was, too, an age of copying in architecture, and in all such ages fashion rather than invention rules. and fashion dictated mediaeval buildings, not Roman ones. Hence for a long time the new Portland cement con creto was only used in foundations, in blocks for dock walls, and similar constructions, or in floo*' u whore short lumps of it could be placed between •steel girders So far there was no revolutionary idea, the concrete being

merely used, lor its mass and weight as stone or brick might be. Gradually, however, it was discovered that cement concrete was a very good protection for steel, against lire. It became the practice to cover girders and stanchions with it. It was then found that the concrete not only adhered to the steel, but, expanding and contracting at the same rate, made almost one substance with it. Some brilliant person or persons then, whose names, I fear, are lost, hit on the idea of making the combined steel and concrete act together as one thing, the steel being so placed in the concrete that it would resist any pulling force (which the concrete from its nature could not do) and the concrete so placed as to take any compressing force, which it is well able to sustain Till this happened the steel girders and uprights did all the work, the concrete used being a mere covering. After the invention, however, the steel was reduced to thin rods sufficient to take the tension, and placed in the position where the tension would come. In this way the great invention of the Portland Cement Age came about, and was gradually given the name of ferro-concrete. It meant, indeed, a. new material which combined in itself all the Chief functions and possibilities of both concrete land steel. Imagine a new kind of stone, but with, the toughness of steel, and obviously a new kind of architecture is called for. It is this architecture, more prominent on the Continent so far than it is with us, which may cause, and probably will, in the end, a 5 great a revolution in building as did Roman concrete eighteen centuries ago. The main characteristics of this new architecture, which is arising wherever Ihe new material is used lor its special qualities and not in imitation of a stone architecture, arc the thinness of the supports ami the length of the span possible from support to support. Ferro-concrete is really more like tough wood than stone. Already wo lay a coating of' it on our new’ loads and make our larger drain-pipes of it. In buildings, great overhang of features is possible such as balconies without apparent support. Indeed, most of the construction work that is usually done in wood can be better done in it and without fear of decay. The new roof of Rheims Cathedral and the roof of the new Cathedral at Liverpool are both in it. The beetle which in the end destroys most wooden roofs has no power against it. We all know’ how it is used in bridges, and the light elegant forms it leads to The Seine between Rouen and Paris is crossed by many such structures. Most of our English railways are now lined with wire fences, in which the posts are ’ made of it. Abroad one sees tall lattice signal and telegraph posts so constructed, and consequently requiring no upkeep. One day we may find our furniture made of it. It only requires a satisfactory concrete made of pumice or some light material to render that possible. The world is threatened to-day by a shortage' of timber. II so, in the concrete building lies Hie remedy and a universal one, for almost every place can provide, the ingredients. 'I he building of the future will not bo of the heavy monumental typo implied

by bricks and stone. They will be more akin to Gothic than Classic, but with angular forms, for curved moulds are difficult to make. Ferro-concrete structures have a certain gauntness about them. but at the same, time there is great airiness and light. The eye, trained to the proportions of si.one buildings, will have to be ti.iincd to the new ones this new material implies and makes possible. I hey may at. first, be thought ugly, but in the end, the professor thinks, we shall find them possessed of strong power. What, he asks, is the change in our civilisation (hat this will imply.