Question

Related to subject of ( Reinforcement Concrete )
Answer the following in very short answers:-
Please use typing only.

1- What is the difference between a Type A and Type B splice?

2- Why is it conservative to assume that the moment capacity and area of steel vary linearly instead of using the quadratic relationship?

3- Why is this helpful to speed up the moment design?

Answer 1

In case of reinforcement concrete the splices has the sence as the lap . When at the time of reinforcement the length of the bar is not as same as the design of the structure .In the many cases it has to increase its lenght by joining another steel bar which is in steel design known as the splice and in reinforcement concrete known as the lap .There are codal provision for joining the steel bar from one to another and the lenth of lap is depend on the percentage of lapped bar.

1-There are many ground for the classification of the splices and one of the ground is based on percentage of lapped bar

TypeA-If the percentage of the lapped reinforcement is 50% ,it mean if there are N number of bar passing through, but out of these only N/2 number of bar has to be lap or splice. In this case the length of lap is calculated as ≈45 D where D is the diameter of the bar

TypeB-If the percentage of the lapped reinforcement is 100%,it means if there are N number of bar passing through and the all N bar has to be lap or splice .in this case the length of splice or lap will increase and will be calculated as ≈50 D where D is the diameter of the bar.

In both the type of the splice the calculation of the splice length is on the basis of the of codal provision in India it is used IS456

2-If the splices used in concrete reinforcement then only dead weight increaes and the moment capicity has the direct relation with load and not the qurdatic relation .

3-As it is told that the moment capacity have the direct relation with the load and in case of splices the load or being more preciously dead weight increases so the design moment will increase or speed up