Parallam epoxy creep?
Parallam epoxy creep?
(OP)
I was just wondering, given the recent incident at the Boston tunnel involving creep failure of epoxy in tensile connections (http://www.ntsb.gov/Publictn/2007/HAR-07-02.htm), are Parallam's certified or tested against creep failure?
Given that Parallam's are more reliant on the long term strength of their binding epoxy than GLULAM's, this must be a pretty big concern.
Given that Parallam's are more reliant on the long term strength of their binding epoxy than GLULAM's, this must be a pretty big concern.





RE: Parallam epoxy creep?
The thickness of the epoxy is not as great as that in chemical anchors so I would think the creep properties would not be as exagerated, but....
The report did mention that some epoxy anchors did pass a creep test.
csd
RE: Parallam epoxy creep?
RE: Parallam epoxy creep?
csd
RE: Parallam epoxy creep?
RE: Parallam epoxy creep?
Mike McCann
McCann Engineering
RE: Parallam epoxy creep?
Have you learned any more on this topic? After thinking about the issue, I had some additional thoughts.
Wood beams experience long term creep generally equal to about 1/2 the dead load. This is true of solid sawn lumber and of glulam. I would expect that this would be true of Parallam also. My guess is that epoxy creep is not a concern because of the creep in the wood.
RE: Parallam epoxy creep?
I did a bit of research online and heard that the creep problem occurs with formaldehyde based epoxy adhesives.
I'm not sure the exact adhesive composition for the more common laminate / wood fibre beams on the market