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I'm looking at a high-rise with almost entirely concrete structure, but a large number of block walls in the building.

The job has specified a bond beam at the top of all walls, which are all just below an existing slab, since all masonry is installed after the structure is complete. Detail drawings are very clear that the bond beam must be the top course - we can't fill the second-from-top course and close the space above with a non-grouted course.

Is there a trick to grouting the top course once installed? I feel like I must be missing something, because we have to do this with a good 11,000 linear feet of block wall.
 

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Is your bond beam made from lintel block or bond beam block? Lintel block you might be able to cut notches or core drill holes every few feet and get a looser mix to flow into via a hose. (Bond beam blocks you can try the same but its a little tougher). You could also core drill through slab above with an engineer's approval, but the risk there is hitting rebar. The downside is the sheer number of holes to drill, and not being able to see how well the voids are filled. When we encountered this exact problem on a project, the engineer redesigned the detail, so that the block stopped a course short of the slab, then our rebar extended up from the block to a poured in place bond beam. That's a solution that would have to come from the architect or engineer though.
 

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I don’t do the kind of work you do, but I run into the same situation on residential foundation replacements.

Seems like a goofy detail.

You can drill from the top, and use a grout mix with a super plasticizer, if they are OK a with you drilling the slab.

You can see if the engineer can design a different detail.

Submit an RFI.

You can try to form and pout the last course in lieu of block, but pumping that full, even with holes drilled in the side, is gonna be a *****.
 

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Discussion Starter #5
Can you pour the beam when you pour the floor?
Unfortunately not. Each of the floor slabs is being poured in relatively quick succession, meaning that the floor above will be getting poured. It's likely that the first 5-10 levels above ground will be poured by about the same time we're first allowed to start the lowermost parkade walls.
 

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Why didn’t the mason fill it when they topped the wall off?

Isn’t that part of the mason contractors scope of work??

We always do, they can use a grout pump


David
 

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This sounds like something that is critically important so it's critically important that the exact procedure is very clear to make sure the end result is what is required, definitely time for a RFI, there should be a working how to detail supplied by the Architect/Engineer.
 

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This sounds like something that is critically important so it's critically important that the exact procedure is very clear to make sure the end result is what is required, definitely time for a RFI, there should be a working how to detail supplied by the Architect/Engineer.

Architect/Engineer are usually not concerned with means & methods.

An RFI may work if it worded properly.

It can be beneficial to provide a solution with the RFI.
 

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Unfortunately not. Each of the floor slabs is being poured in relatively quick succession, meaning that the floor above will be getting poured. It's likely that the first 5-10 levels above ground will be poured by about the same time we're first allowed to start the lowermost parkade walls.
I guess I don't understand the scope of the project then.

I just assumed the walls needed to be up first to hold up the floor.

Is it a steel structure with block as the infill?
 

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Architect/Engineer are usually not concerned with means & methods.

An RFI may work if it worded properly.

It can be beneficial to provide a solution with the RFI.
They usually aren't but if there is a situation where what is designed can't be built as designed then it's incumbant upon the design team to work with the contractor on coming up with a practical solution to solve the problem. If it goes south no one's going to want to hear 'well, he should have been able to figure it out'.
 

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I guess I don't understand the scope of the project then.

I just assumed the walls needed to be up first to hold up the floor.

Is it a steel structure with block as the infill?
Probably, I found that when they create the design/print the blueprints the engineer will basically copy and paste the specs from the industry standards...

Usually CMU walls have to have a bond beam with rebar and grout on the top coarse before the next floor is poured so that is probably the specs that they included even it makes NO sense

He might want to talk to the architect/engineer and see if that as a misprint. I have had several projects where the scope of work made no sense for the type of building


David
 

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Why didn’t the mason fill it when they topped the wall off?
The base building contractor is pouring concrete slabs for every floor. Then a block mason comes in and fills in between the floor and the underside of the slab above, from column to column, with block.
 

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Looking at this sketch ... the base building contractor has built the white columns and slabs, when they are done the mason goes back and build the brown infill walls.

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E56480EF-9F7A-4AFC-A0F3-4BEFAFDF9BDF.jpeg
 

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It looks to me like the sequence of events is screwed up. Build the block walls on each floor as they're poured.

Note that I know nothing about this sort of construction, I'm just looking at how I would build it if it landed in my lap and I didn't know any better.
 

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The base building contractor is pouring concrete slabs for every floor. Then a block mason comes in and fills in between the floor and the underside of the slab above, from column to column, with block.
Ok so why didn’t the mason contractor fill it up?


I wish I got these kind of jobs, where I could do all the easy work and let somebody else do all the hard work.....


If the top course is a bond beam then you can drill a hole every few feet and use a grout pump to fill it up, but From what I am reading I highly doubt the top course is a bond beam


David
 

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[B]jsprplc2006[/B] most likely you'll just run your mesh then bond-beam block, 5-6 at a time, leaving an end open so you can run your rebar through and a grout pump hose. The last block or two in the bond beam you'll need to core drill a hole for your hose. Then again it may be easier to just drill every3rd block and inject the grout. It's typically a 1" hole. They also make an open-ended "H" bond beam block (or speed block) that might help you get around rebar since you won't be able to drop the CMUs in place. I've seen old parking garages around my neck of the woods getting retrofitted with infill CMU walls so not as uncommon a situation as you may think.
 

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I'm not aware except from going top down.

On residential houses i do the bond beam 2 down and run vertical steel 2" below sill plate and pour the bond beam. You should have already poured the cells. I then make a g block but only cut halfway down and just trowel in the stuff. Next day is just fling it in there.

Not as good as if it were new, but what can ya do.
 

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This is one of those cases where the architect / engineer was pretty friggin stupid. Better have a sit down with them and talk about it.
If the bond beam is just to stiffen the wall laterally at the top, good chance you could install it second to last course, then use standard block on top course? Of course, that will require the designer to eat a little crow and realize they designed a relatively unbuildable detail.
 
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