Author Description

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. 1921 edition. Excerpt:... floor or office building floor may be supported on all four sides by beams or girders, or they may be supported by columns having enlarged heads or capitals without any beams or girders. In the former the floor slab and the stem of the beams form a T-beam and are designed in accordance with the principles already stated for such beams. In the latter the method adopted for the determination of the floor thickness and the area of the steel reinforcement is more or less empirical as the problem is not capable of statical treatment. The floor slab supported by means of beams or girders on all four sides will be first considered. The Committee of the Am. Soc. C.E. in their final report on reinforced concrete structures, state that floor slabs supported by beams on all four sides should be designed as continuous over the supports. The reinforcement at the bottom of the slab between the points of inflexion or contra-flexure should be designed for the positive bending moment, and over the supports the reinforcement at the top of the slab should be designed for the negative bending moment. The bars may be bent up from the bottom to the top at or about the points of contra-flexure. In the case of a square slab one-half of the total bending moment should be assumed to be carried by the reinforcement in each direction parallel to the sides of the panel. If the slab is oblong and the long side is greater than one and a half times the short side, the total bending moment may be assumed to be carried by the transverse reinforcement parallel to the shorter side. If the slab is oblong, and the long side is less than one and a half times the short side, the proportion carried by the transverse reinforcement along the shorter side is given approximately by...