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)))

Slabs:-

1- Name two benefits of designing a one way slab as a series of one foot wide strips?

2- How do we calculate the minimum thickness for a slab?

3- Why is it a good idea to use the minimum slab thickness?

4- What is the minimum cover on an internal and external slab?

5- What is temperature and shrinkage steel and why do we have it?

Answer 1

Q.1. Two benefits of designing a one way slab as a series of one foot wide strips :

First you have to understand we are taking unit width because we need unit area strips ( means we take unit width in both X and Y directions ). If we design a unit area 1 ft² strip of slab it will going to be same for the entire slab.

So by taking 1 ft wide strip benefits are :

a. Each strip now acting as an individual beam carrying uniformly distributed load so our beam formula for maximum bending moment = wl²/8 etc are going to work no separate relations and equations are needed also the complexity of design and calculations are reduced.

b. Now our strip is just like a beam of 1 ft width and effective depth is same as the depth of slab so we can easily find the area of steel for it and spacing of bars and hence our slab is designed.

If we conclude basic reason for taking 1 ft strip is to break our slab in small beams which is easy to design.