fish wrote:
I recently bought a 16# sledge from home depot for smashing an old
sidewalk, it worked well. i put a little muscle into it but for the
most part i let the hammer do most of the work.

Fish



Yes! That is the right way to break up concrete. Full force, round
house blows are great for building muscle mass but are wasted effort.
What does it are repeated moderate blows in the same spot (or in a line
if breaking a slab). At the start it will 'ring' with each blow then
after repeated blows "thud" . The block or slab has cracked.

Harry K