cepennington
Touchy Subject to say the least.
Fastener Design/Lubrication is the key to an achieved pretension procedure.
Research Council on Structural Connections
Specification for Structural Joints Using ASTM A325 or A490 Bolts, June 30, 2004
9.2.3. Twist-Off-Type Tension-Control Bolt Pretensioning: The inspector shall observe
the pre-installation verification testing required in Section 8.2.3. Subsequently, it
shall be ensured by routine observation that the splined ends are properly severed
during installation by the bolting crew. No further evidence of conformity is
required. A pretension that is greater than the value specified in Table 8.1 shall not
be cause for rejection.
Commentary:
The sheared-off splined end of an installed ASTM F1852 twist-off-type
tension-control bolt assembly merely signifies that at some time the bolt was
subjected to a torque that was adequate to cause the shearing. If in fact all
fasteners are individually pretensioned in a single continuous operation without
first properly snug-tightening all fasteners, they may give a misleading indication
that the bolts have been properly pretensioned. Therefore it is necessary that the
inspector observe the required pre-installation verification testing of the fastener
assemblies, and the ability to apply partial tension prior to twist-off is
demonstrated. This is followed by monitoring of the work in progress to ensure
that the method is routinely and properly applied within the limits on time between
removal from protected storage and final twist-off of the splined end.
Tell them that for this fastener to maintain it's designed performance the lubricant/assembly can not be compromised by the effects of weather.
Most are a water soluble lubricant anyway it ain't rocket science but any dummy should realize the ill affects.
If you want to go to page 125 of this paper it starts there with the conclusions of this research paper that
RCSC is doing on stuff like you ask
http://www.boltcouncil.org/files/FinalReportonTCBoltsPhase1.pdf"Delayed Installation of ASTM F1852 Fasteners - 2nd Phase"
University Of Toronto
Dr. Peter C. Birkemoe
Earlier research had shown that bolts placed in the steelwork and left for a period of time, prior to
the final installation to a residual tensile force, experience degradation in the achieved tensile force
that is attained and this is delay phenomenon forms the principal parameter of concern in this
investigation. Other important parameters that were identified are the temperature of and moisture
present in and around the fastener assembly at the time of final installation, the strength of the
assembly and the configuration of the assemblies during atmospheric exposure.
If you want to really do something get the Engineer of Record in on it.
My ΒΆΒΆ's
( Unless the connections are slip Critical or the initial tightening does not at least bring about a Snug-tight condition, I wouldn't worry about it)
But If I was the TPI I would have to put a stop to it for non-conformance.
Either way
Good Luck
Marshall