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 (87000/(87000+fy)) For Case 2

Design Steps for T-beam