Transcript File
Reinforced Concrete Design-4 Design of T beams By Dr. Attaullah Shah Swedish College of Engineering and Technology Wah Cantt. Quick 30 minutes- Open Book Quiz − Compare WSD and USD methods. (5 min) − Design a simply supported singly reinforced concrete beam of span 15 ft having a superimposed dead load of 1K/ft and live load of 1.5K/ft. fc’ = 4000 psi and fy= 60000psi (15min) − Determine the moment capacity of doubly reinforced beam of size 12inx18in having 6#8 bars in the bottom and 2#8 bars at the top. Use the above material stresses. (10min). T Beams Case 1: Compression area in Flange a<t − If the depth of equivalent stress block is equal or less than flange depth, the beam may be designed as rectangular beam. − In such case − Nominal moment Capacity − If the thickness of a > t, then T beam analysis will be required Case 1: Compression area in web a>t − The tensile force in steel T is resisted by two components one C1corresponding to A1 and other C2 corresponding to A2 Compression − Area of steel corresponding to compression in Flange is given as − The nominal resisting moment by flange is given as − The remaining steel area ( As-Asf) is compensated by the compression in web. − The additional resisting moment is given as − The total nominal resisting moment is given as: − Maximum and Minimum Steel - For Case - The area of steel reinforcement As is given as - The balanced steel ratio is given as - The balanced steel ratio is given as - - For Case 2 (87000/(87000+fy)) Design Steps for T-beam