Lanterna Rally

Author: H. Grattan Tyrrell

Publisher:

Published: 2015-06-30

Total Pages: 276

ISBN-13: 9781330515792

Excerpt from Concrete Bridges and Culverts, for Both Railroads and Highways Bridges of solid concrete are superior to those of any other material. They are as permanent as stone, and have a less cost. Masonry bridges and aqneducts built by the Romans are still standing, and some of them in use. A few old cast iron bridges remain, dating back a century or more, but a majority of the modern ones built of wrought iron and steel have a very limited existence. Forty years ago, steel bridges were believed to be permanent structures, but it is now well known that they do not generally last longer than from twenty to thirty years. Solid concrete bridges are superior to those in which reinforcing metal is required for resisting tensile stresses in the arch ring. Continuous water-soaking reduces the adhesion of concrete to steel by about 100 percent, and the effect of shocks and vibrations also tends to destroy the bond. It frequently occurs that cracks develop, sufficiently large to admit water, and when water and moisture reach the reinforcing metal, it is then only a few years before the metal is destroyed by rust. An old wire suspension bridge that recently failed, was examined and reported on by the writer, and it was found that failure occurred because of the rusting and breaking of the wire cables embedded in the anchorage. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.