Some Mooted Questions in Reinforced Concrete Design eBook

This eBook from the Gutenberg Project consists of approximately 181 pages of information about Some Mooted Questions in Reinforced Concrete Design.

Some Mooted Questions in Reinforced Concrete Design eBook

This eBook from the Gutenberg Project consists of approximately 181 pages of information about Some Mooted Questions in Reinforced Concrete Design.
the other way; and there are all gradations between.  The reinforcing, therefore, should be spaced the minimum distance only in the mid-region, and from there on constantly widened, until, at about the quarter point, practically none is necessary, the slab arching across on the diagonal from beam to beam.  The practice of spacing the bars at the minimum distance throughout is common, extending the bars to the very edge of the beams.  In this case about half the steel is simply wasted.

In conclusion, the writer wishes to thank Mr. Godfrey for his very able paper, which to him has been exceedingly illuminative and fully appreciated, even though he has been obliged to differ from its contentions in some respects.  On the other hand, perhaps, the writer is wrong and Mr. Godfrey right; in any event, if, through the medium of this contribution to the discussion, the writer has assisted in emphasizing a few of the fundamental truths; or if, in his points of non-concordance, he is in coincidence with the views of a sufficient number of engineers to convince Mr. Godfrey of any mistaken stands; or, finally, if he has added anything new to the discussion which may help along the solution, he will feel amply repaid for his time and labor.  The least that can be said is that reform all along the line, in matters of reinforced concrete design, is insistent.

JOHN STEPHEN SEWELL, M. AM.  SOC.  C. E. (by letter).—­The author is rather severe on the state of the art of designing reinforced concrete.  It appears to the writer that, to a part of the indictment, at least, a plea of not guilty may properly be entered; and that some of the other charges may not be crimes, after all.  There is still room for a wide difference of opinion on many points involved in the design of reinforced concrete, and too much zeal for conviction, combined with such skill in special pleading as this paper exhibits, may possibly serve to obscure the truth, rather than to bring it out clearly.

Point 1.—­This is one to which the proper plea is “not guilty.”  The writer does not remember ever to have seen just the type of construction shown in Fig. 1, either used or recommended.  The angle at which the bars are bent up is rarely as great as 45 deg., much less 60 degrees.  The writer has never heard of “sharp bends” being insisted on, and has never seen them used; it is simply recommended or required that some of the bars be bent up and, in practice, the bend is always a gentle one.  The stress to be carried by the concrete as a queen-post is never as great as that assumed by the author, and, in practice, the queen-post has a much greater bearing on the bars than is indicated in Fig. 1.

Point 2.—­The writer, in a rather extensive experience, has never seen this point exemplified.

Point 3.—­It is probable that as far as Point 3 relates to retaining walls, it touches a weak spot sometimes seen in actual practice, but necessity for adequate anchorage is discussed at great length in accepted literature, and the fault should be charged to the individual designer, for correct information has been within his reach for at least ten years.

Copyrights
Project Gutenberg
Some Mooted Questions in Reinforced Concrete Design from Project Gutenberg. Public domain.