278 STEEL REINFORCEMENT 



number of rods necessary to secure the desired sectional area. 

 The two rods at the top are bent upwards, as shown at b, 

 and the ends c are turned over so as to add to their grip in 

 the concrete. The stirrups in both frames are shown at d, 

 f -in. round bar iron being used for the stirrups of the frame 

 shown in view (a), and light strap, about J in. X 1 in., for the 

 stirrups of the construction shown in view (b). In the 

 latter frame, the section at the right of the figure shows 

 the reinforcing bars held in the clamping device, which con- 

 sists of the casting e, the clip f , and the stirrup g. These 

 parts are secured by means of a bolt h. 



Pin-Connected Girder Frame. Another type of rod rein- 

 forcement built up in the form of a girder frame is illustrated 



FIG. 10 



in Fig. 10. This reinforcement is known as the pin-con- 

 nected girder frame, and it is arranged so that the frames 

 forming the reinforcement of the beams and girders may be 

 connected by pins and links at intersections and over column 

 supports. 



Cummings System of Reinforced Concrete. The system of 

 steel reinforcement shown in Fig. 11, known as the Cum- 

 mings loop-truss girder, consists of a series of main reinforcing 

 bars a, to which are attached a set of smaller bars b that turn 

 up at the ends and form a loop welded at the ends. These 





