Question

Problem (2): Given: As an engineer, you have been asked to design a reinforced concrete floor system consists of a 5-in concrete slab supported by T-beams of 24-ft spans. The T-beams are spaced 4 ft and bw (width of the beam part 15". Total height is 25 inches. If you try to find the steel required for T-beam for moment due to Mp- 500 ft-kips and M-300 ft-kips, what would be the type of T-Beam (Regular or True T-beam)? fc 3,000psi, fy 60,000psi. In this problem answer the question by right calculations, you don't need to design or find the amount of steel (Just determine type of the T-Beam) (14 points)

no please

Answer 1

GIVEN DATA Span of beam Slab thickness 5 in Breadth of web 15 in d22.5 in -25-2.5] -2.75 ft F4-15"] Effective depth, Clear distance, left side right side 2.75 ft [-4'-15"] fe3000 psi fy= 60000 psi Strength of concrete Yield Strength of steel, Bending Moments 500 kip.ft 300 kip.ft CULATIONS STEP-1: Effee flange width, b a) b shall not exceed one-fourth of the span length 24 x 12/4 72 in b) The effective overhanging slab width on each side of the web shall not exceed eight times the slab thickness, that is,8xh40 in 40 15 40 95 in c) half the clear distance to the next beam web on each side b33 /2 1533/2 48 in b48 in (the smallest of the three values) Therefore STEP-2: Computation of factored bending moment M. = 1.2 MD + 1.6 M, 1080 kip.ft Therefore, design moment, STEP-3: Computation of area of reinforcement, As Assuming」:0.95 jd21.375 = 1080 x 12000 / (0.9 x 60000 x 21.38) 11.23 in2 STEP-4: Computation of a 0.85f b 11.23x 60000 0.85 x 3000 x 48 5.5 in 5 in Since a is greater than hf, compression zone is not rectangular and must be designed as T-beam Therefore, type is: T-beam