Concrete-Steel Construction Volume 1 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1914 edition. Excerpt: ...to determine the cross section of the inner ring rod, with the same definiteness as that of the radial rods, but that is unimportant. Its position has already been fixed as not more than / from the edge of the cap, where I is the distance from the top hoop or collar band of the column to the edge of the cap. STRESSES IN CONCRETE OF HEAD 211 The vertical shearing stresses may be regarded as sufficiently resisted outside the mushroom by the concrete alone. The critical cylindrical surface separating those areas where the shear may be assumed to be safely carried by concrete alone, from those areas where the steel may be relied on to carry as much of the shear as may be required, should evidently be taken somewhat inside the outer ring rod, but just where is of no particular consequence. The supposition of the existence of a crack at X, either actual or potential, on which our computation of the stresses in the radial rods has been based, is sufficiently satisfactory so far as the rods themselves are concerned; but it seems desirable to consider in more detail the phenomena attending the development of the stresses in the concrete at and near the edge of the cap, especially in soft concrete when the limit of its compressive resistance is reached in this region. The horizontal compressive resistance of the concrete at the lower surface of the slab is that already treated in (38), and it is our present object to consider how that is to be combined with the vertical supporting pressures under the radial rods, and with the horizontal and vertical shears in the slab due to bending. These latter are greatest in the neutral surface, as has been previously stated, and according the general theory of stresses are equivalent to, and may be replaced...