How  COMBINATION FOOTINGS are different from  isolated spread footings ?

Using the drawings for Billy’s Convenience Store, in Appendix F, the quantity of concrete and reinforcing steel required for the spread footings.

15. A contractor is building thirty-two (32) of the 2'- 0"x 2'- 0"x 0"-10" spread footings shown in the drawing below. Using the material schedule at the bottom of the page, answer the questions a to f below. Concrete (cy) • Rebar (lbs) 2 x 12 Forms 2 x 4 stakes (each) • Nails (lbs) "x12" CF Plan View 2-37 Side View (2) #4 brach way top and botto ▲ Section A-A Concre "x12" Concrete Farm 2"x4" 2-6 Side View Material Specification Frequency Waste, of Use % Concrete 4,000 psi 1 3 Rebar # 4 (0.668 lbs/lf) 1 10 Forms 2 x 12 in. x length 4 10 Stakes Oak, 2 x 4 x 18 in. 4 25 Nails 3½ in. common 1 10 2-67 2x 12" Conte Form 4x4 Sales Concrete (2) reach way top and bott 2-3 Section A-A Comments Use exact measurements then add waste 2" clearance from ends to forms Use exact measurements then add waste Total length is 18" 1 lb/100 bf of total lumber (forms plus stakes)

Question 8 A sample slab section view is shown below: *4 0 10" EW 30 Felt Joint El. See What should be the correct reinforcement configuration in plan view for this slab? What should be the correct reinforcement configuration in plan view for this slab? 10" 10" 10" 10"- #4 bars 10"- 10" 10" 10" #4 bars 10"- # 4 bars 10"-