REINFORCED CONCRETE 83 



3. Axial compression, on the steel. 



Rods, shapes, or built-up members, when reinforcing the 



concrete 15/ c 



Shapes or built-up members when independent. 



[See Pars. 12 (c), 65 (c), 117 (c).} 



(d) Shear, on the concrete. 



1. Direct shear only (i.e., shear uncombined with either ten- 



sion or compression) for: 



Beams, having no web reinforcement 40 Ibs. (2%) 



" , " bent-up reinforcement 60 " (3%) 



" , " web reinforcement of bent-up 



bars and stirrups 120 " (6%) 



One-half of compression 



2. Shear and compression com- 



, i values given above un- 

 bined, equal amount of each . . . 



\ Interpolate between values 



3. Shear and compression com- . r 



, . , ,, ,. i given under (a) 1, and 



bmed, other ratios ~L 



4. Shear, on the steel (any grade) 10,000 Ibs. 



(e) Diagonal tension, on the concrete 40 " (2%) 



" , on the steel 15,000 ' ' (40%) 



(/) Bearing. 



Concrete on concrete (equal areas) .... 500 " (25%) 

 (less area on 



greater area) 600" (30%) 

 (g) Bond between 



Concrete and plain reinforcing bars . . 80 " (4%) 



' ' drawn wire 40 " (2%) 



" deformed bars (variable) 100-160" (5-8%) 



349. Other Concretes and Steels. For concretes, differing 

 in strength or proportion of aggregates from normal concrete 

 (Par. 375), substitute for values given above (Par. 348) their 

 ultimate strength in 28 days times percentages as indicated, the 

 maximum increase over same being limited to 25 per cent. 



For steels, differing in strength from structural steel grade 

 (Par. 193), substitute for tensile values given above (Par. 348) 



