Old technology rules...
 

Hi,

just clearing the front garden (or front concrete) and the drive prior to
having block paving laid.

We decided to do the digging out ourselves, mainly because it is more fun
than working.

However, it is raining at the moment :-(

Our block paving guy lent us a concrete breaker thingie over the weekend -
like a very big SDS drill.

I wasn't making very much progress on one of the slabs, so he came back with
an alternative tool.

This is a 6' steel bar; point at one end chisel shape at the other.

One end under an 8' * 4' * 5" thick concrete slab and him jumping on the
other end (and he isn't a small guy) and amazingly the whole slab tilted up.

Some rubble under it to keep it slightly raised, and a few hefty welts with
a sledge hammer and the concrete was broken up and heading for the skip.

I am on the difficult bit now - a continuous slab which has manhole and
drains in - so I can't tip this one up.
However I am still amazed at how straightforward it was to lever up a slab
of concrete.

You do need a pretty solid fulrum, mind.

Cheers

Dave R

--

On Mon, 4 Jul 2005 09:39:03 +0100, "David W.E. Roberts"
wrote:

Hi,

just clearing the front garden (or front concrete) and the drive prior to
having block paving laid.

We decided to do the digging out ourselves, mainly because it is more fun
than working.

However, it is raining at the moment :-(

Our block paving guy lent us a concrete breaker thingie over the weekend -
like a very big SDS drill.

I wasn't making very much progress on one of the slabs, so he came back with
an alternative tool.

This is a 6' steel bar; point at one end chisel shape at the other.

One end under an 8' * 4' * 5" thick concrete slab and him jumping on the
other end (and he isn't a small guy) and amazingly the whole slab tilted up.

Some rubble under it to keep it slightly raised, and a few hefty welts with
a sledge hammer and the concrete was broken up and heading for the skip.

I am on the difficult bit now - a continuous slab which has manhole and
drains in - so I can't tip this one up.
However I am still amazed at how straightforward it was to lever up a slab
of concrete.

You do need a pretty solid fulrum, mind.

Cheers

Dave R

Concrete is strong under compression, but week in tension. You moved
it from one to the other. Steel however is the opposite, so a mixture
of the two is massivly strong in a much wider set of applications.

Rick

Rick wrote:

Concrete is strong under compression, but week in tension. You moved
it from one to the other.

True.


Steel however is the opposite

False. Steel has a much higher compressive strength than concrete.


--
Grunff

Grunff wrote:

Rick wrote:

Concrete is strong under compression, but week in tension. You moved
it from one to the other.


True.


Steel however is the opposite


False. Steel has a much higher compressive strength than concrete.


but steel BARS buckle at much less than the ultimate compressive
strength,and steel SLAB weighs far more than concrete and costs a fortune...

The Natural Philosopher wrote:

False. Steel has a much higher compressive strength than concrete.


but steel BARS buckle at much less than the ultimate compressive
strength,and steel SLAB weighs far more than concrete and costs a
fortune...


Yes, I know why steel is used to reinforce concrete - I was just
clarifying the point about relative compressive strength...


--
Grunff

"David W.E. Roberts" wrote in message
...
Hi,

just clearing the front garden (or front concrete) and the drive prior to
having block paving laid.

We decided to do the digging out ourselves, mainly because it is more fun
than working.

However, it is raining at the moment :-(

Our block paving guy lent us a concrete breaker thingie over the weekend -
like a very big SDS drill.

I wasn't making very much progress on one of the slabs, so he came back
with
an alternative tool.

This is a 6' steel bar; point at one end chisel shape at the other.

One end under an 8' * 4' * 5" thick concrete slab and him jumping on the
other end (and he isn't a small guy) and amazingly the whole slab tilted
up.

Some rubble under it to keep it slightly raised, and a few hefty welts
with
a sledge hammer and the concrete was broken up and heading for the skip.

I am on the difficult bit now - a continuous slab which has manhole and
drains in - so I can't tip this one up.
However I am still amazed at how straightforward it was to lever up a slab
of concrete.

You do need a pretty solid fulrum, mind.

LOL! Very nice post, thanks :-)

Mary

In message , Grunff
writes
Rick wrote:

Concrete is strong under compression, but week in tension. You moved
it from one to the other.

True.


Steel however is the opposite

False. Steel has a much higher compressive strength than concrete.

I know what he said, but I think what was meant was that it buckles in
compression

--
geoff

raden wrote:

False. Steel has a much higher compressive strength than concrete.

I know what he said, but I think what was meant was that it buckles in
compression


So would a concrete rod of the same dimensions.


--
Grunff