Question

. A 5 in thick simply supported reinforced concrete one-way slab is part of a roof system. It is supported by two masonry block walls, as shown below. Assume a superimposed dead load (roofing, insulation, ceiling, etc.) of 15 psf and a roof live load of 30 psf. Check the adequacy of the slab, including the required shrinkage and temperature reinforcement. Use た= 4,000 psi and fy = 60,000 psi. #4 @ 9 in. #4 @ 12 in. 6 in s i 10'-0" 12 in. 12 in Figure for Question 1

Answer 1

Given that To find fo_2 of s - 2 slab = R = 6'' therefore delta = 6 - N''/L - 25'' = 5'' (1) slab - 2 L_1/L_s = 25/10 = 2.5 > 2 one way slab span = 10' i) slab function gives to 6/12 times 150 = 75 psi (ii) cylindrical fishing = 5 ps6 (iii) Medial and system = 5 ps 6 \r\n iv) weight platform = 20 Ps6 total DL = 10 sp6 v) flour five del = 80 ps6 w_4 = 1.2 times 105 + 1.6 times 80 = 12,600 + 128 = (2) 2) w_l = 0.2658 (3) ACI moment coefficient for slab l = 10' Beam worth = 12;: = 1' ln = 10 - 1 = 9' (4) Maximum -+ve movement at = w ln^2/10 = -(0.26) times 4^2/10 = 2.1 Kmpl \r\n (5) maximum_ve moment = ln^2/16 = + 0.26 times 9^2/16 = + 1.32 (6) Reinforcement for -ve moment at support