Principles of Reinforced Concrete Construction

Abstract

IN this edition a considerable number of changes have been made, and much new material has been added. In every case records of experiments have been brought right up to date: this is especially the case in regard to the adherence between the concrete and the reinforcing metal, to the shear strength of beams, and to the strength of columns. The properties of concrete and steel are fully dealt with in chapter ii. The important question of the value of the modulus of elasticity of concrete is discussed in the light of the most recent experiments. The authors are of opinion that for most calculations in regard to strength the value of the modulus should be taken as 2,000,000 lb. per sq. in. The tests on bond by Mr. Withey seem to show that the intensity of the bond per square inch is not affected by the size of the bars, and that the average bond strength as determined by direct tension is much higher than in the case of beam experiments. The difficulty of carrying out these latter tests prevents their more usual adoption. In determining the strength of reinforced-concrete beams, the authors have wisely, for the greater part of the book concerned with this problem, assumed that the stress-strain curve for concrete is practically straight within the limits of the working stresses adopted in practice; in sections 60 to 70 they have, however, deduced a series of flexure formulæ on the assumption that the stress-strain curve is a parabolic arc. In both cases the concrete is assumed not to take any tension. Engineers engaged in structural work involving the use of this material for transverse loads can, therefore, check their results by both sets of formulae, and thus secure an additional guarantee of the security of their design. Designers learn almost as much from the results of carefully conducted experiments as they do from all the formulas that fill the various textbooks, and it is satisfactory to find a whole chapter devoted to a description and a discussion of a carefully selected series of rupture tests of both beams and columns.

Principles of Reinforced Concrete Construction.

By F. E. Turneaure E. R. Maurer. Pp. x + 429. Second edition, revised and enlarged. (New York: John Wiley and Sons; London: Chapman and Hall, Ltd., 1909.) Price 15s.