Hey Folks,

Not all concretes are the same. How that
particular batch is blended can make it different.
My dad had a slab poured for the garage and he
wanted it really substantial, but a very smooth
surface. A number of years later he got a
grinder and wanted to mount it directly to the
floor with bolts. He tried his drill with a
diamond concrete bit and didn't even dent it. He
borrowed an industrial hammer drill and used a
diamond concrete bit and all he got was a
depression. After trying a number of other items
he gave up. He ended up getting a wheel rim and
welding a pole with a platform on it and filled he
rim with concrete and mounted the grinder on the
platform. Several times through the years he
tried in other places to drill holes in the
concrete and each time gave up. It was the
hardest concrete that we had ever experienced. My
dad and I poured and worked a lot of concrete over
the years.

We found out later that the concrete company we
used was doing a special project in our area for a
Federal Bridge project that produced prestressed
concrete beams and it was surmised that we got the
leftovers one day. What ever was in it it hardly
was ever stained by oil or any petroleum product.
If it got wiped up pretty quick you hardly new it
had been split on the surface.

Usually surfaces of concrete deteriorate over a
period of time no matter how smooth it is from the
start. After almost 40 years this concrete is
just as smooth as it originally was produced.

Tom L.L.
=============================
"Charles" wrote in
message
...
On 10 Apr 2003 21:14:01 -0700,
(Eric Hanson) wrote:

Hello,

I am planning on extending my pond in the
coming weeks. The current
pond is about 22' x 7'. I want to dig an
extension to make it an
L-shaped pond. The problem that I am having is
that I would have to
"dig" through a 6" thick concrete walkway. And
I have no idea how to
remove it safely and with a low cost. I quickly
tried to pound it with
a sledgehammer, but it did little to the
concrete. Not even a crack. I
quickly stopped because I was worried about the
fish and vibrations.

Does anyone have any suggestions/comments?

Please see my site for images to get a better
understanding of what I
am trying to do. I look forward to ANY
responses. Thanks for your time

http://www.pobox.com/~ehanson/aquaria_pond.html


How about sawing it into smaller pieces, rental
yards have diamond
saws for that purpose. Cement that I have
broken up seemed to be a
lot weaker if I could get it upside down and
break it from the bottom.
No idea why that would be, just seemed that way.


_

- Charles
-
-does not play well with others