REPRESENTATIVE EXAMPLES OF WORK.
3S1. Buck Building. Fig. 1S7 shows the typical structural floor-plan, above the first floor, of a building constructed for J. C. Buck at Fifth and Appletree Streets, Philadelphia. The architects were Ballinger & Perrot, and the ing was constructed by Cramp & Company, Philadelphia. The building has a frontage of 90 feet on Fifth Street, and a depth of 61 feet on Appletree Street, and is seven stories high. The ing was constructed structurally of reinforced concrete, except the first floor and the columns in the lower floors. The floors were all designed to carry 200 pounds per square foot. The side walls were constructed of light-colored brick, and trimmed with terra-cotta. The first floor 'was constructed especially to suit the requirements of the chemical company that is to occupy the building for several years. If this company should leave the building when their present lease expires, it will very probably be necessary to reconstruct the first floor; and therefore it was structed of structural steel, as it will be much easier to remove a floor constructed of structural steel than one constructed of rein forced concrete.
The footings for each of the interior columns were designed as single footings. They were 10 feet square, 30 inches thick, and were reinforced as shown in Fig. 1SS.
The columns in the basement, first, and second floors, were of structural steel, and fireproofed with concrete. The wall columns were either square or rec tangular in shape ;and the in teriorcolumns were round, being twenty inches in diame ter. The stress allowed in the structural steel of these columns was 16,000 pounds per square inch of the steel section; but no allowance was made for the four small bars placed in the column. These' steel cores were provided with angle brackets to support the beams, and with spread bases to transmit the stress in the steel to the foundation. The cores are com posed of angles and plates, and are riveted together in the usual manner. The columns were built in sections of a length equal to the height of two stories. The extra metal required in this practice was very small; and the expense of half the joints, if a change of section had been made at each floor, was saved.
The general outline and details of these steel cores are illustrated in Fig. 1S9. In the exterior columns, the steel cores were used in the basement and the first, second, and third floors, where neces sary; in the interior columns, they were used also in the fourth story, and in two columns the structural steel extended to the sixth floor line. The exterior columns above the structural steel, and also the columns in which struc tural steel was not required, were in general reinforced with S bars 1 inch square, in the lower floors; and this amount of steel was gradually reduced to 4 bars 1 inch square, in the seventh story. In the interior columns, the reinforcement above the steel cores consisted of S bars inch square, in the floor just above the structural steel; and the number of these bars was gradu ally reduced to 4 in the seventh floor.
The floor-slab was 5 inches thick, and was reinforced with ? inch square bars spaced 6 inches on centers, and bars spaced 24 inches on centers, the la t ter being placed a t right angles to the former. The roof slab was designed to carry a live load of 40 pounds per square foot, and was 31 inches thick. The reinforcement con sisted of n c h bars spaced 6 inches, and the same sized bars spaced 24 inches at right angles.
The floor-beams were in general S inches wide, and the depth below the slab was 1S inches. The amount of reinforcement in the beams varied, depending on the length of the beams. Most of the beams were reinforced with 2 bars 1 inch square, and 1 bar 1-k inches square. The 11 inch bar was turned up or trussed at the ends, and the 1-inch bars were straight. The roof beams were 6 by 12-inch below the slab, and were reinforced with 2 bars inch square, except in the longest beams, in which 2 bars 1 inch square were required. A finch bar, 5 feet long, was placed in the top of all floors and roof beams, where they were framed into a girder. The ends of these bars were turned down. The stirrups were made of round bars, and were spaced as shown in the detail of the beam. See Fig. 190.