Coring Through Concrete Headstock

[axle]

We have been required to do some rectification works on a recently constructed reinforced concrete headstock. This rectification works involves the drilling of 1200mm deep, 45mm diameter cores into the concrete. We have been diamond core drilling and all has gone well except for the last core where we have struck a lot of reinforcing steel which has just been destroying the core barrels and subsequently have not been able to get through. Is there any other process that can easily drill through steel and concrete at the same time? We are hitting the steel at approximately 300mm down. We have to get this core down to 1200mm deep and the maximum width that the core can be is 50mm. Any suggestions?

 

[Ron]

I assume you are using a water cooled coring bit. Most good quality diamond coring bits will cut right through rebar without an issue. Perhaps you just need to use a better coring bit.

 

[axle]

Yes we are using a water cooled coring bit. The problem seems to be that we are following a bar all the way down the core, not just slicing through a bar that crosses the core.

 

[dik]

They even have coring bits for cutting through steel plate. One of the projects they have to core about 25' with a 6" dia core to cut out an existing PT strand...

Dik

 

[Ron]

OK..you're trying to core down a vertical rebar...move over a couple of inches and do it again.

 

[axle]

Moving the core is obviously the simplest solution and if possible would have been done the moment we hit steel. Problem is due to the steel we are trying to avoid coring through and other space requirements the hole has to be where it is.....

 

[Ron]

OK...then buy a couple of extra bits, take it slow, plenty of wash water and move on.