REINFORCED CONCRETE. 63 



Since the stress-strain curve is a straight line in com- 

 pression 6-7, and p c = the intensity of compressive stress 

 on the plane 3 - 5 we have 



p c _ x — d . _ c(x - d) 



C JO ' ' X 



••• * = f (* - d > 2 1 



P/ = ^( Po + c) = b -g(2*-d) 

 S h = Zbsl = P." = ^ (2x - d) 



AX 

 C 



S =8 



. 7 , 6blx 



.. b = 



8d(2x-d) 



. p „ Qblx cd(2x — d) 3 , 7 



' ' Fc ~8d(2x-d) Yx -$ mc 



p c = p; + p.-^ix-ay + §S£_ 



M= -^(cr-cl) 3 +^(2x~d) 2 -f f s ab(/i-a'-a:) 

 3cr 4a? 



Example — Let h = 36 inches 5 

 b' = 36 inches 

 b = 12 inches 

 a = 3 inches 

 d = 6 inches 



^ ~ 15 



c = 500 



f. = 16000 



s — 50 



ab = 7*5 square inches 



