STEEL REINFORCEMENT 



271 



FIG. 2 



illustrated at g, and should 

 extend at right angles to the 

 axis of the girder. Sometimes , 

 similar rods are used in the 

 slab over beams, as shown 

 at k. 



The longitudinal reinforce- 

 ment of the concrete columns 

 consists of four round rods /. 

 It is customary to project 

 them above the concrete of 

 each story about a foot and to 

 splice them by lapping and 

 wiring or by using pipe sockets 

 m, as illustrated. Frequently, 

 it is not possible to lay out 

 beforehand the electric-light 

 or power wiring, but if this 

 installation is to be adopted 

 IJ-in. pipes to serve as a 

 passageway should be embed- 

 ded near the center of the span 

 of all beams and girders, close 

 to the under side of the slab 

 construction, as at n. 



Kahn System. The Kahn 

 system of reinforced-concrete 

 construction is based on the 

 use of the Kahn trussed bar. 

 A typical monolithic construc- 

 tion based on the use of the 

 Kahn system is shown in 

 Fig. 2. The 

 main reinfor- 

 ting members 

 of the beams 

 and girders are 

 shown at a, and 

 they consist of FIG. 3 



