Gr8 bolt expoxied to CMU wall 1

[dlclarkii]

I've never seen this before and I'm not sure what to say. I'm assuming the Gr8 bolts are inserted into hollow cores and I doubt if sleeve inserts were used. I think the Contractor drilled a hole; squirted epoxy; and stuck the bolt in the hole. What does everyone else think? What you're looking at is a WF8 header spanning 18' between two block walls. The header supports a crane runway rated for 1T. The structure weighs more than the crane capacity.

 

[TehMightyEngineer]

Can you safely load test the crane rail? Probably the simplest and most expedient way to go about this and you doubly get the crane rail load tested.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[dlclarkii]

Can't get test weights into the building so I'm doing an engineering study instead.

 

[SwinnyGG]

No pullout possible? You sure about that? What's the effect on the upper bolt pair when the crane is loaded? Looks to me like those bolts see tension.

Personally, I'd probably be advocating that the flange and block be drilled in place with proper anchors installed. This would be quick and not very expensive.

Given that a grade 8 bolt was used instead of a proper adhesive anchor, I'd be reluctant to assume that the install was performed with any sort of care or attention to detail. An improperly installed adhesive anchor can have little or no actual strength.

 

[TehMightyEngineer]

I've seen crane companies use water bags in places they couldn't bring in test weights.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[Ingenuity]

I guess that 'blob' is weld - judging by the adjacent weld splatter - or maybe it is epoxy that ouzed out of the hole during placement?

 

[bridgebuster]

I agree with your assessment: The contractor stuck a bolt in a hole filled with epoxy. No way to test it but perhaps you want to assume that the pullout capacity is similar to a rebar and calculate based on Appendix D.

 

[Lomarandil]

Looking at the second photo, I think epoxy is more likely than weld.

I agree about performing a load test -- although an Appendix D calc may give you an estimate of the weight you'll be looking at.

My guess agrees with most of the posters above: not much.

----
The name is a long story -- just call me Lo.

 

[hokie66]

The key to whether this is adequate is the block wall. Is the block completely core filled? How do you know?

 

[DDBPE]

If the contractor did this and it was not the proper way in the first place, how sure are you the hole was the right diameter for the epoxy, the bolt is the right length, the correct type of epoxy was used (if this is a vertical face, then was a low viscosity/low sag epoxy used too prevent the epoxy from only coating one side of the bolt and hole), the hole was clean when they placed the epoxy, etc.... Also, these are in hollow core CMU's, another issue I have with it unless they were filled.
I have drilled and placed many types of anchors (horizontal and vertical) most of which required some sort of pull test to verify which you cannot perform with this type of installation. Anchor manufactures are very specific with the installations as they have already tested them.
Seems too risky to me, I would not sign off on it, unless you are absolutely sure of the installation and witnessed it. Especially if this is a overhead crane runway, not sure I would walk under it.

 

[oldrunner]

Start by tapping the blocks under the connection to see if the cell (and adjacent cells) were filled. The control is the upper bolts trying to pull out plus the bearing pressure on the block facing and hopefully core grout.