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RE: More On Ungrouted Baseplates for Traffic Signal/Signage Struc ture s

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Bill,

The Center for Transportation Research web site is:
http://www.utexas.edu/depts/ctr/, but I don't think that the reports are on
line.

The specific reports are:
1.	Factors Affecting Anchor Bolt Development by Lee and Breen, Research
Report 88-If
2.	Behavior and Design of Ductile Multiple-Anchor Steel-to-Concrete
Connections by Cook and Klinger, Research Report 1126
3.	 Load-Deflection Behavior of Cast-In-Place and Retrofit Concrete
Anchors Subjected to Static, Fatigue, and Impact Tensile Loads, by Collins,
Klinger, and Polyzois, Research Report 1126-1
4.	Design Guide for Steel-To-Concrete Connections, by Cook, Doerr, and
Klinger, Research Report 1126-4F

If nothing else, you should also get a copy of "Strength Design of Anchorage
to Concrete by Ronald Cook, by the Portland Cement Association.  There is a
great reference list on p B-18 if you want to really have some fun.

In general they confirmed that ACI 349 was accurate, and the head on anchor
bolts was sufficient to develop the strength of the anchor even for high
strength ASTM A193 B7 steel.  And you are correct that bond strength is no
good.

If the length of anchor bolt is getting too big, you can intercept the shear
cone with steel rebar from below and transfer the tension forces into the
rebar.  You can use Lenton Terminators to develop the rebar in a relatively
short distance.

For the lateral load on the anchor bolt take a look at the shear / tension
interaction curves in reference 2.  If you want to avoid that issue, you can
cast in a top setting template with shear lugs.  That way the anchor bolts
in shear will bear on the steel setting template, and you avoid the local
crushing at the top.

Regards,
Harold Sprague


> -----Original Message-----
> From:	Polhemus, Bill [SMTP:wlpolhemus(--nospam--at)sbinfra.com]
> Sent:	Tuesday, May 16, 2000 3:11 PM
> To:	'seaint(--nospam--at)seaint.org'
> Subject:	RE: More On Ungrouted Baseplates for Traffic Signal/Signage
> Struc ture s
> 
> But this only PARTIALLY answers my question (which, I'll admit, probably
> wasn't framed in such a way to catch all of it).
> 
> HOW do you design the anchor bolt embedments?
> 
> If it is a "mechanical anchor" I suppose the old "tried and true" method
> of
> ACI 349 might pertain (surely we don't count the "bond strength" between
> the
> smoot anchor bolt and the concrete).
> 
> But a "pull out cone" only gets you so much; there is a point beyond which
> further embedment is pointless.
> 
> I'm just out of my comfy paradigm here and need some further opinions.
> 
> Is the study or studies mentioned by you below, available anywhere on the
> 'net?
> 
> -----Original Message-----
> From: Sprague, Harold O. [mailto:SpragueHO(--nospam--at)bv.com]
> Sent: Tuesday, May 16, 2000 1:54 PM
> To: seaint(--nospam--at)seaint.org
> Subject: RE: More On Ungrouted Baseplates for Traffic Signal/Signage
> Struc ture s
> 
> 
> Bill,
> 
> I would be very surprised if the Texas DOT assumes the embedded template
> is
> serving as a mechanical anchor.  The Texas DOT was the sponsor of several
> studies by Lee, Breen, Cook, Doerr, Klinger, Collins and Polyzois on
> anchor
> bolts at the Center for Highway Research and the Center for Transportation
> Research at the University of Texas in Austin that concluded that the
> embedded nut was more than adequate for anchor bolt anchorage.
>