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RE: RCSC A325 bolt spec

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Title: RE: RCSC A325 bolt spec

>[In the] new "Specification for Structural Joints Using ASTM
>A325 or A490 Bolts" [from] RCSC [the] new Section 1.4 [gives]
>information to be specified by the EOR in the contract documents.
>I am confused by the 4th item on the list: specify "whether slip is
>checked at the factored-load level or the service-load level,
>if slip critical joints are specified". But why does the contractor
>need to know this information? Doesn't the EOR do the design and just
>specify the required type of bolt/joint? (The contractor would need this
>information if connection design is left up to the contractor as is the
>practice in some areas, but this requirement implies that it must always be
>specified.)

Good point, Bill. We (the Bolt Council) had in mind the case when connection design is delegated and wanted to emphasize that the decision as to which provisions for checking slip resistance should be used is properly made by the EOR. If the EOR designs and provides the connections, that information would not be needed.

>Regarding the 3rd item on the list: If the EOR specifies a joint to be
>"slip-critical" but does not specify the "class of slip resistance", is
>there a "default class", e.g. Class A slip resistance (0.33 slip
>coefficient)?

There is no default class. Today, I think I see Class B more often than Class A, either because the bare steel is blast cleaned anyway or because paint systems can be obtained and applied to obtain a slip-critical rating and most of those get you a slip coefficient of at least 0.5 (Class B) when used properly. Galvanized surfaces are different, though -- Class C.

>And as an editorial comment, shouldn't the 3rd item reference Section 5.4
>rather than Section 4?

The actual statement that the EOR must specify the required class of slip resistance is made on page 23 (in Section 4 under Joint Type). That's why the parenthetical reference is made to Section 4, not 5.4. You are correct that Section 5.4 is where slip-critical design strength is determined.

>Adding a section on Drawing Information seems like a good idea, but I am
>confused by what it requires.

Thanks for the feedback. It helps.

Charlie