In article , The Medway
Handyman writes
Jonathan wrote:

So, the tv isn't THAT heavy, but the concrete is just not giving! I
drilled a smaller pilot hole (took 5 minutes to go 1" with a 5mm bit)
but when it came to the 8mm bit, really nothing was happening. I gave
up after about 15 minutes and 3mm having gone slightly deaf!

You can hire an SDS drill from a tool hire shop which should do the job.
Just checking - your drill wasn't in reverse was it?


Hire such a useful tool???. Haven't got a birthday coming up?, make an
excellent present to yourself!.


--
Tony Sayer