SLAB, BEAM, AND COLUMN TABLES 



193 



70. Given a column load of 80 tons, what size of square column and what 



total area of steel cross-section is required if 3 per cent of longitudinal 



reinforcement is employed? 

 71 Given a column whose effective dimensions are 20 in. X20 in. and 



whose cross-sectional area of steel amounts to 14 sq. in. What load 



will the column sustain? 



72. Given a column load of 200 tons, what will be the design of hooped 

 column required, if the area of longitudinal rods is taken equal to 3 

 per cent of the sectional area of the enclosed concrete? 



73. (a) Using Tables 2 and 3 design a rectangular beam to span 15 ft. 

 and to carry a live load of 1500 Ib. per linear foot. Beam is to be 

 simply supported. 



(b) Design this beam using Table 8. 



The flange of a T-beam is 48 in. wide and 4 in. thick. The beam is 

 to sustain a bending moment of 800,000 in.-lb. Assume the ratio of 

 unit cost of steel to cost of concrete = 60. Take b f = 9 in. and determine 

 the economical depth of beam, also the amount of steel necessary. 

 Consider the computed cross-section as sufficient to resist shear. 



74 



TABLE 1. AREAS, PERIMETERS, AND WEIGHTS OF RODS 



