beam bar splice bend

[ticas]

In lap splice in beam bars. Won't bending of grade 60 bars to align the splice bars cause some slight brittleness in the bend corner of the splice? Is no bending recommended at the cost of some looseness in the surrounding stirrups?

 

[ticas]

This is an example of a beam top bar midspan splice.....


bar 2 ********************* **************************** bar 1
***
****************************** bar 2
|
|
bent bars

the bar 2 is bent so that the ends can be bundled with the upper bars. Bending is done so that all stirrups can be aligned with all the bars in the beam. But for grade 60 bars, is it better not to bend it?

 

[ticas]

bad ascii...

Just imagine a top bar midspan splice, you have to slightly bend the bar in one of them to be bundled with the other bar. Has anyone done any grade 60 splice without bending?

 

[BAretired]

Not me, but I don't see why it could not be done if the splice bar can be held in position while concrete is vibrated around it.

BA

 

[ticas]

BAretired. You mean you bend one of the bars in the splice? Are you not concerned that grade 60 bars are more brittle hence bending can cause some loss of strengh?

 

[BAretired]

Grade 60 bars should be able to take a bend without significant loss of strength. Bending is necessary whenever the column size changes, but avoiding the bend is desirable when possible.

Using straight lap bars is possible, but the lap bars cannot be "wet set" in the lower column or strength will be lost. Offsetting the upper bar relative to the lower bar is sometimes done but this is not possible for smaller columns. Running vertical bars two tiers instead of one results in more bars than required at the splice, so some loss of strength can be tolerated. It also results in fewer splices.

BA

 

[ticas]

BAretired. I'm talking about beams. Have you done any splicing without bending in the beams?

 

[hokie66]

It is common practice not to bend (crank) beam bars. They are just displaced to suit at lap points.

 

[BAretired]

Sorry, didn't read your post carefully enough. I thought you were talking about column steel. For beams, I agree with hokie.

BA

 

[ticas]

hokie, so you don't bend (crank) beam bars at the splice? but how do you handle stirrups that no longer exactly fit the bars but more loose?

 

[hokie66]

That doesn't matter. Splices aren't at maximum shear locations anyway, so the stirrups at that point are just bar supports. Tie wires will hold the whole assembly together adequately.

 

[ticas]

You said Grade 60 bars should be able to take a bend without significant loss of strength, so how come it is common practice not to bend (crank) beam bars? What is the reason?

 

[hokie66]

Bending them wouldn't hurt the bars, but there is nothing gained structurally, so why do it? The reason for not doing it is that it is unnecessary. This is reinforcing steel, not furniture.