A PRACTICAL TREATISE ON NATURAL AND ARTIFICIAL CONCRETE: ITS VARIETIES AND CONSTRUCTIVE ADAPTATIONS. BY HENRY REID. ACTHOR OF 'THE SCIENCE AND ART OF THE MANUFACTURE OF PORTLAND CEMENT,' ETC. E. & F. N. SPON, 46, CHARING CROSS. NEW YORK: 446, BROOME STREET. 1879. PREFACE. OWING to the favourable reception accorded to my Concrete book of 1869, which has passed through a second edition, I have been induced to prepare the following work, treating more fully on the subject, and I trust more worthily of this important question. The subject of concrete and its varieties now receives much attention, more especially in consequence of the numerous novel adaptations of comparatively recent origin. In its more extensive application for important engineering works there has not been so much attention given to the accurate scientific rules according to which this material should be made. For minor purposes, however, and in what may be regarded as its domestic direction, great efforts are being made to keep pace with the most recent knowledge on the subject of concrete-making. Of the paving and pipemaking industries, together with a variety of others of probably less importance, because not yet sufficiently established, I have in these pages given such information as will at all events lead to a further consideration of their peculiar features and advantages. Marine architecture has during many years been beneficially assisted by that system of concrete-making which received its greatest impetus when Portland cement was first made good enough to warrant its acceptance by engineers without fear of dangerous results. In too many cases, however, the acquisition of a faultless matrix has been regarded by engineers as the only desideratum, and a degree of indifference has in consequence resulted, to the quality and character of the aggregates. In the best examples of concrete of established quality I have shown that much of their excellence is due to the care bestowed on their fabrication and a just and intelligent knowledge of the matrices and aggregates of which they are composed. There has always been much difficulty in advancing good reasons why concrete made from Portland cement was superior to that produced from other matrices having a more ancient and established reputation. The apparently strong and indisputable reasons which antiquity furnished to the advocates of lime and puzzolana tended much to retard the use of Portland cement long after its excellent qualities had been well known and approved. Roman buildings and others of more recent origin were cited as evidence against the adoption of the new cement, and perhaps its greatest and most remarkable success is due to the fact that through it constructive feats have been accomplished, which the most sanguine of ancient constructors could not have supposed possible even in their dreamiest of moods. Ponderosity and bulk were not unknown to ancient architects and builders, as the Pyramids and Roman ruins fully show. Practical science had not, however, in those remote ages furnished the means required to enable the engineers of antiquity to lift a River Liffey concrete block weighing nearly 400 tons, or float a Tay Bridge pier to its required site and deposit its weight of 200 tons safely and unharmed in deep water. Notwithstanding these engineering achievements, now regarded as of comparatively easy accomplishment, considerable harbour and dock works are still progressing regardless of the lessons which such able and advanced engineering teaches and illustrates. Less attention is attracted to these important works because the public have, or at least take, but little interest in their progress. It is otherwise, however, 1 |