Question

Assume normal concrete weight (wc = 143 lb/ft) with specified compressive strength fc = 4,000 psi, and steel Grade 60 (fy = 60,000 psi). For design loads assume dead load wd = 30 lb/ft? (excluding self-weight) and live load we = 100 lb/ft. Finally assume that the steel percentage ratio is equal to p= 0.18fc/fy. Design an interior one-way simply supported slab with a 15 ft span using the above assumptions. Show sketches of one-way slab cross section, including reinforcing bar sizes, arrangement and spacing. (Hint: do not use minimum thickness per ACI, use instead a slab thickness of h = 5 in) tttttttttttttt we

Answer 1

Given data- concrete weight- 143lb/ft3

Fc'= 4000psi, Fy= 60000 psi, dead load- 30lb/ft2.

Given data :- normal concrete weight Wea 143 lb/ft? compressive strength = f = 4000 steel grade 60 ty = 6oooopsi Dead load Wo = 30lb/ft2 Live load We = 100lb/ft2 Steel). Ratiop= 0.98 to span = 15ft. Slab thickness a sin ty Isht o loads and moment Dead load a 30 lb/ft2 live load a you ablft2 depth for self load & Sina 0.416ft 0.42ft self toad = 0.42X 143 *1 = a depth x width x emcrete weight - 60.06 lb/ft3 Total load = 60.06+30+100 = 190.06 lb/ft2 (Wa) factores load - I.SX 190.06 = 885.09 lb/ft2

Mu factored moment = Wale? 285.0g x 16 Mus 8018, 16 lb ft cultimate moment Resistance for fy 60 mulina = 0.138 fc bd2 8018.16 = 0,138x 4000 x16d? da 3.81 inch < sinch ok we provid Sinch depth and calculated depth is 3.8lin So we are safer side. 2 Reinforcement required : steel lo Ratiogiven = 0.18 fe' Pt - Ast = 0,012 9 Too za

so provide a 0.012 of steel 0.012 X 1X5=0.06 in2 using 0.3937 inch dia bar so spacing: - S = 1x D x(0.3937.)2 == 2.02 in 0.06 ni provide 0.3937 in dia bas @ 3 inch spacing

Provide reinforcment in transvers direction @ 0.12). of gross area - 0.0012 x widthx depth 0:12 X 1X5 - 6x 10 ² = 0.006 in ² Spacing by using Zum or (0.315 inch) dia bas 1x x 0,315,2 = 12.98 inch finch which is very high so provide spacing of Zum (0.315 inch) dia bar yout food distributed bar or sheas Reim forcement 0.3150 @ 7inch V main Reinforcement 10mm or 9.34376 @3ins Reinforcement detail
reinforced one way simply supported slab.