×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Hilti Allowable loads into CMU

Hilti Allowable loads into CMU

Hilti Allowable loads into CMU

(OP)
I am designing an angle supporting a concrete beam with hilti Kwik bolts into a CMU wall. I see the loads they give are allowable loads. I have factored reactions from my beam, and designed the angle using factored loads and plastic design.

Now would you re figure a service load and re figure the tension/shear on the bolt and use the allowable loads, or stick with the factored loads, and eat into the factor of safety for the anchor?

Thanks
Replies continue below

Recommended for you

RE: Hilti Allowable loads into CMU

Always follow the manufacturer's written directions. Do as Hilti tells you to do, and where they are silent, contact their Field Engineering group. Very helpful.

RE: Hilti Allowable loads into CMU

Can't you back into your original loads - take off the factors - and determine the service loads onto the anchor?

RE: Hilti Allowable loads into CMU

(OP)
Im going to do that, bring them back to service loads and design.
Thanks

RE: Hilti Allowable loads into CMU

Sounds like the right approach. The KB 3's have factors of safety of around 4.

“Faith is taking the first step even when you don’t see the whole staircase.” MLK

RE: Hilti Allowable loads into CMU

I have often thought that in a case like this that if the bolts end up internal to the beam perimeter, then the pullout limit state might not apply and you can use the pure shear load.

RE: Hilti Allowable loads into CMU

I see several options but going back through the calcs without the factors is the most precise.

Other options I have used:
1) Contact Hilti
2) Use your factored loads directly against the allowable loads. Yes, you essentially get penalized, but it's only safer than before. You just increase the factor of safety.
3) Use the smallest factor to get back to allowable loads. I.e. if the tension/shear factored load was 1.2DL + 1.6LL, dividing your load by 1.2 would bring you to a conservative allowable load.

2 and 3 are useful to me when it seems impractical to go back through a couple pages of calcs. When it comes to situations like this, I'll never eat into the factor of safety, and will only add to it.

RE: Hilti Allowable loads into CMU

(OP)
Thanks. I calculated the service loads. I did notice they are using FS 5 now for CMU application.

RE: Hilti Allowable loads into CMU

Not to state the obvious, but note also the restrictions regarding installation in fully grouted cells, limit of one anchor per cell, proximity to mortar joints, etc.

RE: Hilti Allowable loads into CMU

(OP)
Thanks, yes I saw that also. Its very tough to get anything with significant load to work in CMU anymore.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close