no running bond and bearing at the lintel end

[Said the Sky]

so I have a situation where the lintel was damaged by a truck and we had to fix it.

upon completion and pictures from the contractor it shows both ends of the lintel has no bearing nor running bond,

I tried a angle ledger to provide this support but I can't seem to get it to pass in terms of hilti Hy270 epoxy. I tried a side mounted plate so I could by pass the edge conditions, but still the hilti rods are not strong enough for 21kN of downward shear force.

anybody have any other ideas on how to fix this without tearing out the entire header and redoing?

tia

 

[phamENG]

How do you know that's a problem? Did anyone inspect the work as they were doing it? I've seen this before where they use a 16" long bond beam block on each end and 8" long lintel blocks over the opening, run the rebar through all the way, and grout it all solid (so the lintel has something approaching 16" of bearing at each end). I don't love it unless the knock the webs out of the bond beam block, but it can work.

 

[Said the Sky]

hey Pham I specially asked them if there is a running bond where the support is or does all the lintel blocks all stop at the wall face, and they said all the blocks stop at the face of the wall and basically only thing holding it up is the mortar joint.

but there is horizontal reinforcing from the lintel that runs into the wall, 2-15M at the base of the lintel, however I don't think we can employ shear friction to masonry?

 

[dhengr]

Said the Sky:
Why is it always our job, gratis, to design and fix things for a builder who is so damn stupid that he doesn’t know that a lintel needs end bearings? Tear it out and fix it, at his cost, then get him off the job. What did your details show, or is the problem partly pointed back at you? Remember that the primary shear strength is from the narrow conc. beam within the outer shell of the block, and a small cap’y. addition from the block outer shells. See if you could make this work, again, at the builder’s expense, assuming what’s there is o.k. otherwise. Cut/break out the outer shell at least one full blk. long, or more, on each side of the joint/jamb, in courses 2, 3 & 4 above the bot. course. Then, clean out the cross shells and interior of the beam. Reinstall the face shells of courses 2 & 3, as forms for conc. fill and rebar, 3 or 4' long. Then, reinstall the 4th course face shells. Maybe this new 2 or 3 course high conc. bm. will be deep enough for the reaction.

 

[Eric C.]

This kind of stuff makes my eye twitch.
If you are sure its incorrect, then have the contractor tear it out and rebuild it correctly. Stand there and supervise if you have to.

 

[dik]

Did they use 'U' blocks? and were 'U' blocks used at the bearing with rebar going in?

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Said the Sky]

Hi Dik U blocks were used for the lintel beam, whether they used it at the bearing is not likely the case as it appears they built the wall up first then framed the beam into the wall and drilled in the rebar. The wall blocks are your standard blocks.

im thinking redo it.... ive already spent alot of time trying to fix their mistake, this way the trades know if they mess up they gotta pay for it instead of always getting bailed out

 

[phamENG]

Certainly a redo. Be careful, of course - if you didn't detail it your company may be helping to pay for the redo. But either way, the owner deserves to have a properly built structure, and whoever is using the building deserves to be safe while doing so.

 

[Said the Sky]

Hi Pham we have in our "general notes" requirement for running bond and also 8" min bearing (half a regular block) so were good there

thanks all

 

[JStructsteel]

is there room to use a channel and column columns down the jamb, make the door a bit smaller?

 

[masonrygeek]

Use trained craftworkers who know what they are supposed to do! There are certifications out there that require the mason to have a minimum level of experience, especially when doing reinforced masonry.

 

[Said the Sky]

contractor found some photos showing the rebar in there prior to fixing it. it seems like the rebar does extend into the wall, however we still don't have the running bond into the wall, contractor said it was how it was built originally so he matched the same pattern.

 

[Said the Sky]

Jstruc,

I was thinking more about what you said and it brought me back to my original solution of providing a angle ledger bolted to the wall to provide bearing on the plate, in theory I should be able to extend my plate long enough down the wall until I got my capacity that I need. I can spec that plate to be bent instead of using angle iron.

each hilti bolt was giving me about 7.8kN so I technically only need three.

 

[KootK]

I don't think we can employ shear friction to masonry?

I'm certainly cool with it. That's basically how all base bed joints resist shear after all.

When we're talking reinforced masonry, it's not as though the face shells are the only, or even the dominant, mechanisms of shear resistance.

 

[Said the Sky]

Kootk good to know I can rely on some of that shearfriction thanks

 

[KootK]

Let's rely on the shear friction and omit the bracket!

 

[Said the Sky]

if thats the case I believe our shear friction is more than enough for 21kN of shear load, thanks Kootk