PREFACE When we consider the fact that fire losses in Canada and the United States amount each year to half a billion dollars, and that the question of commercial economyandcostdetermineswhether buildings shall be built of fireproof and incombustibleMorePREFACE When we consider the fact that fire losses in Canada and the United States amount each year to half a billion dollars, and that the question of commercial economyandcostdetermineswhether buildings shall be built of fireproof and incombustible materials such as re- inforced concrete, or of inflammable materials such as are used in timber construction, it is evident how important it is to the general public to be able to determine on theoretically correct principles whether safe fireproof buildings can be built at practically no greater cost or even less cost than combustible ones.
In case of any un- certainty as to theoretical principles to be applied, the designer is compelled for safety to employ materials in such lavish amounts as to render cost prohibitive. Engineering writers have heretofore failed to apply the mathematical theory of elasticity to those forms of reinforced concrete that differ from beams in their manner of reinforcement and that depend in multiple way systems.
The present for their mechanical action on bond shear as it is involved treatise is devoted to dis- cussion of the elementary principles and the practical problems presented by building work in reinforced concrete. In it an effort is made to dissipate differences of opinion due to lack of familiarity with the mechanics of reinforced concrete such as tend, at the present time, to retard its introduction and to hinder to some extent the rapidity of its progress in the commercial field.
The endeavor is made in this treatise, to bring out these mechan- ical laws, and to treat at length the restraint imposed upon the elements of the composite structure the steel and the concrete in accordance with the fixedprinciples of physics and mechanics in order that rational rules may be more generally adopted for the safe and economic design of this type of fireproof buildings.
Failure on the part of the engineering profession to consider these laws in drawing up building codes, has led to grave errors thereby offer- ing a premium on the more dangerous types of designs in concrete building work, and placing at a disadvantage the more scientific, safe, and conservative types of work as determined by the records of these types in practical construction. While the mechanical laws above referred to are simple in the extreme when once understood, their application is so far from obvious in a superficial consideration of the subject that it has required continuous investigation and patient study on the part of the authors for years of time to determine and classify their operation according to the mechanical principles and laws of physics, and this supplemented by expert observers engaged for many months in the conduct of experiments and tests to decide the questions which this continued study and consideration had raised.
In this treatise patented as well as unpatented types have been included for the reason that while the consulting engineer without license has no right to design patented types, he is called upon to report upon their strength and should for that reason be as familiar with their analysis as with unpatented constructions...