Excerpt from Reinforced Concrete Construction, Vol. 3: Bridges and Culverts, Prepared in the Extension Division of the University of Wisconsin A concrete arch as ordinarily constructed - that is, with fixed ends - is statically indeterminate, but it can be analyzed by taking into account the elasticity of the material. The arch ring is nothing more than a curved beam and is so considered. In arches of stone, it is essential (if we disregard, as we should, the adhesion between the mortar and the stone) that the line of pressure for any possible loading should pass within the middle third of each joint of the arch ring, in order to avoid a tendency for any joint to Open. In arches of concrete, however, the structure considered may be made monolithic and thus capable of withstanding tension, which means that the line of pressure may pass outside of the middle third without endangering the structure. As regards a plain-concrete arch, no variation of the line of pressure from the middle third should properly be allowed in practice, due, of course, to the low strength of concrete in tension but, on the other hand, where concrete is reinforced with steel, a considerable variation of this line may be permitted. 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.