For steel-reinforced concrete, which works better–a metal cutoff blade on an angle grinder, or a concrete cutoff blade?
For a bunch of 4″ reinforced concrete bollards that I wanna lop a few inches off of, what’s the best tool or series of tools…angle grinder with one of the above blades, skill saw with cutoff blade, rented concrete saw used sideways (ugh), or ____???
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You'll either have to buy the blade or there will be a stiff usage fee. I would rent the gas saw with the neat diamond blade.
You will have exposed rebar. Non-structural, I hope? Some years down the road this rebar will rust and cause the concrete to spall. The concrete will eventually fail and you (or someone) will be replacing. What?
I'm going to grind it down beneath the surface and fill it in and cap it.
OK. Cutting to length is the easy part.
I've done the grinder bit. It's not pretty. Those wheels are just too big to get only the rebar without really hogging out a monster hole in the concrete, too.
There is a dedicated drill bit made for cutting through rebar when encountered in a slab or footer. I wonder if that, or a similar less expensive drill bit, could be used to drill out the rebar from the end, much like drilling out a broken bolt. Drill out the majority of the steel and then collapse the remaining shell into the concrete with a punch or chisel.
Funny thing both you and Ralph are here. We just had to lower a bunch of door thresholds 2" in a new slab. Handicap accesibility. There were a lot of 5/8" bolts in the way, and all the walls are 2x6.
A concrete saw worked on top of the slab, then we went in horizontally with an 8" grinder and a diamond blade until we were close to the bolts. Busted the slab off there, and cut off the bolts with a 4" grinder and an abrasive metal disk. Then went back at it with the big grinder. It was not a pleasant job. If you know where the rebar (or is it wire?)is, you might be able to do something similar.
Ralph, this is the SIPs that's getting Grail coated. I offered your suggestion for the jamb extensions, made everybody quite happy. Thing is, the Grail Coat guys are from Florida, and with the recent weather events, they've been having a tough time balancing this job in NC, and taking care of their families in FLA. They're about halfway done, Looks pretty cool, when it's finished, I'll put up some pics. Thanks. Don't worry, we can fix that later!