122 REINFORCED CONCRETE CONSTRUCTION 



Thus web reinforcement is needed. 



a s = (16) (28) (0.0077) =3.45 sq. in. 



We shall select eight 3/4-in. round rods = 3. 53 sq. in. Bond for one rod at 

 the left end of beam is 



25,500 



443 



(2.356)(7/8)(28 



For plain rods, the number which must extend straight to the left end of 

 beam is 



443 



(See page 73.) 



Thus, at this end of beam four rods may be bent up. In a similar manner it 

 will be found that four rods may be bent up at the right end. 



15000 



8'-0" >j 



, 15000* 



^r ^m 



Uniform load - 1000* including 



| I weight of beam 



< { 15'- p" 3 



FIGS. 58, 59. 



The concrete will be found to take care of any diagonal tension between 

 the concentrated loads. Horizontal shear (which measures diagonal tension) 

 at the support is 



V 25,500 

 = = lb ' per lmear mch ' 



and to the left of the adjacent concentrated load, it is 



21 500 



(7/8X28) = 880 lb. per linear inch. 



The total diagonal tension is represented by a trapezoijl (Fig. 59), the 

 parallel sides of which are 1040 lb. and 880 lb. and the length 4 ft. Hence, 



