274 



STEEL REINFORCEMENT 



Merrick System. In Fig. 5 is shown the Merrick floor 

 system of reinforced-concrete construction. The space 

 between girders is occupied by narrow concrete beams a, 

 as shown in the transverse section (a). Between these 

 beams are placed boxes made of one of the many styles 

 of metal fabric on the market. These boxes run the entire 

 length of the clear span of the floorbeams, as shown in the 

 longitudinal section (b), and serve to make the floor lighter. 

 They are indicated in both views by the heavy dotted lines b. 

 Above and below the metal-fabric boxes is a layer of con- 

 crete. This layer is usually made about 2 in. thick, so as 

 to give a flat ceiling and a flat floor surface. 



Gabriel System. The Gabriel system of reinforced-concrete 

 construction consists of steel reinforcing bars to which are 

 attached round-iron stirrups. These stirrups are formed by 

 wrapping a wire a several times around the rer'nforcing bar 





FIG. 6 



and extending it up into the slab, as illustrated in Fig. 6, 

 which shows this particular type of construction complete 

 and in its several details. The wiring of the columns is 

 continuous, and extends from the bottom to the top, as 

 indicated in the figure, particularly in the sectional view (b). 

 Several of the reinforcing rods of both the girders and the 

 beams bend upwards, as shown at c and d, respectively. 

 They also lap over the center of the column to form an 

 additional bond in the concrete, as shown at e. In this sys- 

 tem of construction a lap bar is sometimes provided at the 

 top of the junction, as shown. The slab is shown reinforced 

 with woven wire and shrinkage rods of round iron. 



