







Tor use with 



GRAVEL OR STONE. CONCRETE. 



Maximum 5+ress in 5teel= 16,000 Ibs. per s<^. inch 

 Maximum S+ress in Concrete =650 Ibs. per sq. inch. 



Maximum Bending Momen+ = M 

 where 



w^+o+al load per sq. ff. 

 "L = cen-fer -fo cerrfer span. 



-/f ' 



Area** 0.O7Ss$. 



% o/~ 



6-0" 



7-o" 



7-6" 



6s 



3%$- 



77 



4/ 



350 



/30 



7/ 



36 



320 



208 



/3 



34 



62 



44 



3O 



300 



72_ 



^6_ 



^L. 



Z80 



/64 



66 



47 



3/ 



230 



360 



S2 



25 



420 



Z33 



/7S 



97 



70 



4ff 



30 



2/0 



3S7 



268 



202 



82 



-57 



36 



/o 



30Z 



228 



93 



42. 



/8O 



603 



337 



2SS 



74 



/7o 



4-93 



37 / 



2/Z 



82 



45 



