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BCT for MGS Long Span

Question
State IL
Description Text

For long-span guardrail would it
be acceptable to use steel tubes and CRT drop-in wood posts rather than the
full length wood CRT posts?  What would be a minimum length of the steel
tubes?



 Our Highway Standard 631011 uses
steel tubes and posts, adapted to anchor the w-beam.  (Attached
“218-631011-09 TrafBarTermType2.pdf)



Road Closure Gates
Thrie Beam Guardrails



Date April 5, 2016
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Attachment 218-631011-09_TrafBarTermType2.pdf
Response
Response
(active)

CRT posts have two weakening holes in them, one at ground line and one 16” below ground line.  Thus, CRT can break at two different locations – and did so at various post locations during the evaluation of the MGS Long Span system.  Placing them in steel foundation tubes would prevent fracture at the bottom hole and may change the performance of the system.

BCT end terminal posts are typically placed in steel foundation tubes.  However, BCTs have a slightly different cross section and only one weakening hole.  We do not recommend utilizing BCTs in place of CRTs for the Long Span system.


Date April 5, 2016
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