Corroded RSJ? How to remedy

[buildstudent]

I am a student studying for an HNC Construction, I have a question which I have no idea. Its to do with a Building Condition report for a 3 storey building with basement. They tell you that each floor is supported on 4 RSJs but they are in very poor condiion and corroded at both ends.

Could anyone help me as to what to do to remedy this problem in my hypothetical situation ??

Thanks

Alison

 

[tawelfryn]

I would acrow prop all floors, starting at the basement floor and working up each floor propping. take out top floor rsj, replace with new rsj, making sure that is acrowed up nice and tight and laid on appropriate padstones, then work my way down to bottom floor doing the same.
Might not be the answer they want, but its want I'd do

 

[JonB]

Dear Alison
If you had asked the question on Friday after class you would have had a lot more replies by now.
Keep up the good work.

 

[tawelfryn]

Dear Alison
If you had asked the question on Friday after class you would have had a lot more replies by now.
Keep up the good work.

lol, looks like a Sunday night rushed homework question?

 

[JonB]

Exactly. My grandson is just the same.

 

[buildstudent]

Lol- I am doing my best!

When you say laid on appropriate padstones, is that just the props sitting on like concrete slabs for an even surface?

Would you just lift them of hangers and replace with new ensuring the hangers were stable?

Apologies Im still learning

 

[^woody^]

The ends, or their proper name the bearings , are very important. The section of beam just past where it is supported gets a lot of shear stress - ie the load is pushing down, and the supports (wall or connection) are pushing up

Now, it really depends on how much is corroded and where - in the web or on the flanges.

First thing is to find out what caused the corrosion and stop that. Next treat the corrosion. Then design suitable plates to be welded and/or bolted in the web or under/on the flanges. These plates will then share or carry most of the load that would be on the corroded steel of the beam

Its rare for the beam to need replacing, as often remedial work will do.

 

[gangman]

Woody is spot on. It's a lot easier to sort out an existing beam rather than put in a new one.

A building settles into the deflection of a beam and I've found BCOs tend to want you to leave beams as they are, whenever possible.

 

[AtoZ]

the advice is sound if thats what questioners want to hear.

is it that, or is it how would you go about replacing the beams?



that would be fun, i'll have that job

let us know when you find out please.