This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 Excerpt: ...to calculate all the spans for the worst conditions existing for any one span, since it is very uneconomical to construct Table VI. each span of different dimensions and reinforcement as would be the case for a piece extending over several supports if different values were taken for the bending moments on each span. It ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 Excerpt: ...to calculate all the spans for the worst conditions existing for any one span, since it is very uneconomical to construct Table VI. each span of different dimensions and reinforcement as would be the case for a piece extending over several supports if different values were taken for the bending moments on each span. It may be possible to keep the concrete to the same dimensions and vary the reinforcements, but it is doubtful whether the additional labour spent on the calculations is justifiable. Slabs. With a slab either built in or freely supported at the four edges, supposing (B) the smaller span and (L) the longer, according to the well-known formulae of Grashof and Eankine, the bending moments given for beams must be L4 multiplied by T; where (B) is the span of the beam, and when (L) is the span of the beam the coefficient becomes B4 jj4 __ These coefficients cannot be absolutely correct, since they are derived from the assumption that each pair of strips, parallel to the longer and shorter sides respectively, act by themselves as if free from the adjacent strips. The problem of the distribution of the bending moments on slabs appears to be indeterminate; but the French Government Commission on Beinforced Concrete, in their report, give the values of the coefficients for the shorter and longer 1 1 span as B4 and, L4 respectively. These certainly 1 + 2 L1 1 + 1B4 appear to be more nearly the correct values than the coefficients given by Grashof and Bankine. Table VII. gives the values of the respective coefficients for various ratios of L to B, and in Figs. 16 and 17 curves have been plotted giving the values from-= 1 to = 2. Table VII. For the purpose of calculating the bending moments on slabs, it is advisable to use the coefficients given by t...
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