RECTANGULAR BEAMS 



71 



between the action of vertical stirrups and inclined rods, Figs. 

 38 and 39 have been prepared, based on the diagrams of Messrs. 

 Taylor and Thompson. 1 In these figures the beams are con- 

 sidered broken as shown. The load to the left of the break being 

 heavier will tend to drop, and this downward force, combined 

 with the pull in the horizontal steel, may be resisted either by the 

 vertical rod AB, or by the inclined rod CD. The inclined rod, 

 except close to the end of beam, is in a better position to take 

 stress immediately and, of course, must be more effective in 

 preventing initial rupture. Practically, however, there is no 



(a) 



(b) 



I I 



I I 



.1 I. 



u 



cd) 



FIG. 37. 



great difference in the effectiveness of the two form? of reinforce- 

 ment if closely spaced so as to prevent excessive deformation 

 along the lower portion of the beam. The calculation of the 

 necessary web reinforcement will be taken up later after some 

 definite results of experiments have been discussed. 



38. Bond Stress. Slipping of the bars in a reinforced beam 

 may cause failure, but it can readily be prevented by proper 

 construction. The tension in the horizontal steel near the 



1 From Taylor and Thompson's "Concrete, Plain and Reinforced," 2nd edition, page 445. 



