cutting concrete

[nonbowler]

Will diamond blade cut rebar

 

[Ross/Kzoo]

I don't think so. The diamond blade is sacrificial.

 

[doctordirt]

Yes, we cut reinforced concrete all the time. Wire or rebar it doesn't matter

 

[JoeFin]

Will diamond blade cut rebar

Like Butter

 

[ctgoodman]

It's not the best thing to be cutting through. they are designed to cut the rebar and wire. The more of it you cut though the less life you get out of the blade. If you are cutting expansion joints you generally only cut to a depth of 25% of the slab thickness. So 1" deep on a 4" slab. You most likely shouldn't be cutting into the rebar at that depth. But if you are cutting for removal then that's another story.

Now you also didn't mention if this was rebar already in concrete or if this was loose rebar? If you are just trying to cut rebar to length the abrasive blades are the way to go.

 

[justme-]

We rent those saws (road cutting style in the foreground of the above picture - actually we rent the jack hammers too), gas circular hand held (Stihl rock Boss) and diamond chain saws.
Life span of the diamond and length of time needed for a cut is variable on what size and kind of stone was mixed in and how much and what size reinforcement (rebar and/or mesh) is in it. they will absolutely cut the steel, but it takes longer and wears the diamond much more than the concrete does.

 

[lynnbilodeau]

As stated above, if you are just cutting steel, use the proper abrasive blade.

If cutting reinforced concrete the diamond blade works well, but really should be water cooled. It will last a lot longer.

 

[nonbowler]

Thx y'all u made my day

 

[Ironcrow]

I am thinking of complete demolition and removal of a concrete footing and retaining wall, about 5 feet wide and 10 feet tall. Wall and footing completely exposed on one side. Known to have rebar in it. I was thinking of expansive grout, drill and fill. I'm thinking the grout will fracture the concrete enough to expose the rebar, which I can torch off. Hard to drive one of those saws up a wall I guess. Good idea? Or not? Never tried it.

 

[Ross/Kzoo]

I am thinking of complete demolition and removal of a concrete footing and retaining wall, about 5 feet wide and 10 feet tall. Wall and footing completely exposed on one side. Known to have rebar in it. I was thinking of expansive grout, drill and fill. I'm thinking the grout will fracture the concrete enough to expose the rebar, which I can torch off. Hard to drive one of those saws up a wall I guess. Good idea? Or not? Never tried it.

Seems like a demo hammer would be a better option. Rent it for 4 hours.

 

[hoho98925]

I am thinking of complete demolition and removal of a concrete footing and retaining wall, about 5 feet wide and 10 feet tall. Wall and footing completely exposed on one side. Known to have rebar in it. I was thinking of expansive grout, drill and fill. I'm thinking the grout will fracture the concrete enough to expose the rebar, which I can torch off. Hard to drive one of those saws up a wall I guess. Good idea? Or not? Never tried it.

Bad idea. How thick is the wall? Saw cut wall horizontally near the footing then remove all with a excavator or large forklift.

 

[Ironcrow]

Wall is 2 feet thick at bottom, 18 inches at top. 6 feet away from existing structure. Not too much opportunity for heavy equipment in front of wall. Reason to remove is to make another one 10 feet further back. No access for excavation behind wall, that will be picks, shovels, and buckets. No matter what plan I choose, this isn't going to be easy...

With a 30 foot boom, I could reach the wall from behind the house. Might just pluck it up from behind the house...

 

[hoho98925]

If that is the size, your looking at about 14,000 pounds of concrete just in the wall and that is if your lucky. That would require a large crane. Your best bet is to have it Sawcut into manageable pieces. It's expensive but 100x faster then a demo hammer. There are many ways to do this, all of which are costly.

 

[Hornman]

Drill 1" holes in a one foot grid, then fill the holes with hydraulic cement. The cement will expand and break the concrete into pieces.

 

[brickG-man]

It's not the best thing to be cutting through. they are designed to cut the rebar and wire. The more of it you cut though the less life you get out of the blade. If you are cutting expansion joints you generally only cut to a depth of 25% of the slab thickness. So 1" deep on a 4" slab. You most likely shouldn't be cutting into the rebar at that depth. But if you are cutting for removal then that's another story.

Now you also didn't mention if this was rebar already in concrete or if this was loose rebar? If you are just trying to cut rebar to length the abrasive blades are the way to go.

 

[Ironcrow]

Drill 1" holes in a one foot grid, then fill the holes with hydraulic cement. The cement will expand and break the concrete into pieces.

Yeah, that's what I was trying to get to the bottom of. Sounds like it will work. But, I have concrete saw guys here telling me it is a bad idea. Don't know why. They tried it and it doesn't work as advertised? Dunno. It is relatively easy and inexpensive to try, so I might just see what happens anyway. Can always go to a saw if nothing happens.

I'm planning on bringing a 40 ton Grove crane onto the site this winter to load some trusses. If I wait until then, I can do the rip it out from behind the house plan without paying for the crane to come up twice.

 

[hoho98925]

Yeah, that's what I was trying to get to the bottom of. Sounds like it will work. But, I have concrete saw guys here telling me it is a bad idea. Don't know why. They tried it and it doesn't work as advertised? Dunno. It is relatively easy and inexpensive to try, so I might just see what happens anyway. Can always go to a saw if nothing happens.

I'm planning on bringing a 40 ton Grove crane onto the site this winter to load some trusses. If I wait until then, I can do the rip it out from behind the house plan without paying for the crane to come up twice.

Do that then. Hydralic cement will leave you with a mess. Rebar will hold
the mess together then your only option pretty much will be a chipping gun and a torch

 

[justme-]

At 18" to 24" thick the only saw capable of cutting through would be a concrete chain saw. Uber expensive to buy, rent, operate, and repair. We're the only rental place around us that rents one because of the expense and propensity for damage. the chain will cut the outline for 1 standard size doorway out of a wall of concrete then must be replaced to the tune of about $500. That is variable due to concrete composition including rebar also.
One we have only has a 16" bar and I'm not sure if larger is available outside of industrial products.
I'm thinking if heavy equipment isn't an option, the impact chipping hammer or drill and wedge (like they used to use for splitting rick) may be the most effective I can think of. In my limited experience hydraulic cement doesn't expand enough to crack existing structure, plus it's likely the wall is made of higher strength mix. Although if you're ok waiting until winter, perhaps drilling a ton of holes angled into the face and continuously filling them with water letting the freeze may crack it.
Mind you a hammer, air or electric, in the size needed for that (like the guy is using in the photo above (IR60/90x) isn't light.
you might want to get the advise of a professional in your area along with an estimate.

 

[hoho98925]

At 18" to 24" thick the only saw capable of cutting through would be a concrete chain saw. Uber expensive to buy, rent, operate, and repair. We're the only rental place around us that rents one because of the expense and propensity for damage. the chain will cut the outline for 1 standard size doorway out of a wall of concrete then must be replaced to the tune of about $500. That is variable due to concrete composition including rebar also.
One we have only has a 16" bar and I'm not sure if larger is available outside of industrial products.
I'm thinking if heavy equipment isn't an option, the impact chipping hammer or drill and wedge (like they used to use for splitting rick) may be the most effective I can think of. In my limited experience hydraulic cement doesn't expand enough to crack existing structure, plus it's likely the wall is made of higher strength mix. Although if you're ok waiting until winter, perhaps drilling a ton of holes angled into the face and continuously filling them with water letting the freeze may crack it.
Mind you a hammer, air or electric, in the size needed for that (like the guy is using in the photo above (IR60/90x) isn't light.
you might want to get the advise of a professional in your area along with an estimate.

Most Sawcutting outfits have circular saws capable of cutting this.