CONCRETE DESIGN 299 



the principal slab reinforcement is parallel to the beam, 

 transverse reinforcement should be used extending over 

 the beam and well into the slab. 



"Where adequate bond between slab and web of beam is 

 provided, the slab may be considered as an integral part of 

 the beam, but its effective width shall be determined by the 

 following rules: 



"1. It shall not exceed one-fourth of the span length of 

 the beam. 



"2. Its overhang width on either side of the web shall 

 not exceed four times the thickness of the slab. 



"3. In the design of T beams acting as continuous beams, 

 due consideration should be given to the compressive stresses 

 at the support." 



The notation used for T-beam formulas is the same as 

 before, with the following exceptions: 

 fr = width of flange, in inches; 



b' = width of stem or beam proper, in inches; 

 t = thickness of slab, in inches. 



First assume values for F s , F c and . Also, assume values 

 for d, b', and t. The value to be taken for b is determined 

 partly by the rules just given. Assume an approximate value 

 of A from the formula M = A(d $t)F s . Solve the following 



, . 2ndA+bP 

 formula for kd: kd = 



2nA+2bt 



If kd is less than /, design the same as a rectangular beam ; 

 that is, again find k by the formula 



A A 



k = ^2 pn + (pit)* -pn where p = not -j 

 DO o a 



Then find / by the formula 



j'4si-i k 

 and M by the formula 



Fcjkbd* 

 which must not exceed . 



If kd is greater than *, proceed as follows- Find jd by 



, 3kd-2t t 



the formula jd = d X 



2kd-t 3 



