166 W. H. WARREN. 



In columns the concrete shall not be stressed above one- 

 tenth of its breaking strength, and in computing the steel 

 reinforcing for column flexure a factor of safety of five 

 shall be provided. 



The shearing stress in the concrete shall not exceed 64 

 pounds per square inch. 



If greater shearing resistance is shown, the shearing 

 stress shall not exceed one-fifth of the ultimate resistance. 



The adhesive stresses shall not exceed the allowable 

 shearing stress. 



The coefficient of elasticity of the steel shall be taken as 

 fifteen times that of the concrete, unless another ratio be 

 shown. 



For the computation of columns for flexure Euler's 

 formula shall be used when the height exceeds eighteen 

 times the least diameter. 



The equation for locating the neutral axis in a rectangular 

 beam when expressed by the symbols adopted in this paper 

 for the sake of comparison is : — 



v = E ^P ' '\ - 2ltEc 

 E c • v pE s 



For obtaining the maximum intensity of stress on the 



extreme fibres in compression : — 



2 M x 



and for the maximum intensity of stress in the metal 

 reinforcement : — Af 



f= pbh 2 (u-^) 



For tee-formed sections, such as shown in Fig. 18, the 

 equations remain the same if the neutral axis lies in the 

 flange or at the junction of the flange with the web. 



If the neutral axis passes through the web, the slight 

 compressive stresses in the web may be neglected, and we 



