band and plate question..

WORKSHY-APPRENTICE

WORKSHY-APPRENTICE

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a scaffolder was showing me how diverse band and plate fittings are not so long ago. he told me they are really good ties for pull and shear. does anyone know the shear factor they carry?
 
WORKSHY-APPRENTICE said:
a scaffolder was showing me how diverse band and plate fittings are not so long ago. he told me they are really good ties for pull and shear. does anyone know the shear factor they carry?
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No I don't mate.

But 2 x M12 excalibur bolts through a band are worth a SWL of 20.0kN in shear.

We had some tests done a couple of years ago. Same sceanrio with 2 x 12mm excalibur bolts through a band and plate and the bolts failed before the band at around 62.0kN/68.0kN & 73.0kN (hence the 20kN SWL)
 
Think it would depend on the substrate at that level?
 
The wall you are using. A lot of building's we have done recently couldn't hold a 20kn test as it was soaking wet.
 
aom said:
Think it would depend on the substrate at that level?
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Not really. Bolts would be tested to ensure the SWL is achieved anyway.


Under CDM it's the client who has to ensure that the fabric that you are tying to can support the necessary loads.

---------- Post added at 01:07 PM ---------- Previous post was at 01:06 PM ----------
aom said:
The wall you are using. A lot of building's we have done recently couldn't hold a 20kn test as it was soaking wet.
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Then they fail mate and you have a rethink...

---------- Post added at 01:08 PM ---------- Previous post was at 01:07 PM ----------
WORKSHY-APPRENTICE said:
so it would be safe to use the SWL of the bolts instead of the fitting itself?
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Yes
 
so the best way to look at this is that the tie is only going to be as good as the wall its drilled into?
 
WORKSHY-APPRENTICE said:
so the best way to look at this is that the tie is only going to be as good as the wall its drilled into?
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Yeah same as anything mate. It's no good having 20.0kN leg-load on a standard if the base cannot support 20.0kN.

So you have to look at alternatives.
 
I would say so as it all depends on individual tests.
 
ahh :) thank you guys. just something i was wondering. was a little worried to sound imature or a bit thick to ask :)
 
That's how I went through school and never learned anything. When I went into the working world I decided never to be afraid to ask and never be afraid to appear stupid as that's how you learn. Good bit of info from Phil who could educate a few of us.;)
 
WORKSHY-APPRENTICE said:
ahh :) thank you guys. just something i was wondering. was a little worried to sound imature or a bit thick to ask :)
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Look at it this way mate.

You're using a HIAB to lift gear up and you have:-

5 tonne lifting straps, 2 tonne HIAB and the ground supporting the HIAB legs can only support 1 tonne - then the max you could lift is 1 tonne, regardless of anything else.

Make sense?
 
A point to note here regarding Band and Plates is when they are used in shear and the load is applied there is actually tension produced in the bolt(s) because the Band is being twisted (for want of a better word) off the wall or whatever it's fixed to. So when considering the bolts and anchors one has to design for shear AND tension.

Also....I'm sure this is obvious but the Band has to be correct way around...otherwise it will just rotate...

Other than that a great and versatile fitting, for various reasons we tend to limit the allowed load per Band to 6 kN but don't ask for any technical guidance on Band and Plates used in this manner - there isn't any to the best of my knowledge.
 
Am I right in saying the twist whist present it is minimal?
 
aom said:
Am I right in saying the twist whist present it is minimal?
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No would not say it was minimal...for example a Band with a single central bolt and fixing with 6kN applied as shear the tension developed is slightly higher than 6kN...due to the 'twist' on the Band.
 
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