Reinforced Concrete question: Design a 5 in.-thick simply supported reinforced c
ID: 1713258 • Letter: R
Question
Reinforced Concrete question:Design a 5 in.-thick simply supported reinforced concrete one-way slab as shown in Figure 1. Note: perform the design using a 12”-strip. (a) Define the flexural steel and determine the maximum center-to-center spacing of the #3 flexural steel bars. (b) What is the design moment capacity (Mu) if the #3 flexural steel bars are spaced at 8” on-center? (c) Determine the maximum center-to-center spacing of the temperature and shrinkage steel. Design a 5 in.-thick simply supported reinforced concrete one-way slab as shown in Figure 1. Note:perform the design using a 12-strip. wDm 15-7. + slab weight span length-8ft rmal Weight Concrete 4000 psi Figure 1 Gr.60 steel No. 3 bars (temperature and shrinkage) 5 in d-4 in No. 3 bars (flexural steel) span length-8 ft (a) Define the flexural steel and determine the maximum center-to-center spacing of the #3 flexural steel bars. (15 pts) (b) what is the design moment capacity if the #3 flexural steel bars are spaced at 8" on center? (15 pts) (c) Determine the maximum center-to-center spacing of the temperature and shrinkage steel. (10 pts)
Explanation / Answer
a)M=wl^2/8
wd=15+150*5/12=77.5 lb/ft
wl=30 lb/ft
w=1.2*77.5+1.6*30=141 lb/ft
Mu=141*8^2/8=1128 lb-ft
As required= Mu/(fy*(d-a/2))
with above formula As can be calculated and spacing of #3 bars can be calculated.
(b) calculate As for 8" spacing
from formula Mn=Asfy(d-a/2) calculate Mn