Question

((Reinforcement concrete subject)) using ACI-318.

Please, answer the following questions and make your answers as short as possible. no need for long answer.
You may express your answer as an equation if needed.

(((Please only type your answers)))

T beams:-

1- What is the primary advantage of using a T beam over a rectangular beam?

2- How do we determine the effective width of a T beam?

3- What is the difference between Case 1 and 2?

4- How do I determine if I am in Case 1 or Case 2 for a T beam?

Answer 1

1. First of all t beam is a rectangular beam casted monolithically with the slab.

As it is casted monolothically , the flange section also takes compression stress and hence more resistance to sagging moment

T section reduces depth of the beam , as flange section carries stress.

T beams have a higher second moment of inertia than rectangular beams and thus bending can be resisted more effectively.

For larger section T beam is preferred .

2.

3. Difference between case1 and case2 is based on the position of NA in T section

Case 1 is , where NA is within flange

Case2 is , where NA is below flange .

4. To know whether you are in case1 or case2 , you have to find out the POSITION of neutral axis.