[AT] another new shop

[George Willer]

Just to add a little to H.L.'s comments... the finish of under side of the
concrete is just as important as the top.  It MUST be smooth so the concrete
is exactly the same thickness everywhere!!!  It's changes in thickness that
concentrate the stresses that cause cracks.  After it is prepared, the
concrete truck MUST NOT drive on it!

My shop floor is in two sections, the largest is 34' x 40'.  It is 4" thick,
poured directly on the original sand base (carefully graded by my Farmall
Cub/grader blade) without any reinforcement in 1990.  There are no cracks.

George Willer

----- Original Message ----- 
From: "H. L. Staples" <hlstaples at mcloudteleco.com>
To: <at at lists.antique-tractor.com>
Sent: Sunday, August 08, 2004 1:00 PM
Subject: Re: [AT] another new shop


Cecil Monson--wrote

 " Another question I have is concerning the concrete floor. On the
new shop I have now, I specified 6" of concrete with steel laid on the
whole thing and centered inside the slab. "

Cecil

The last building we put up here on the farm was about 20 years ago and it
was built for a feed mill.

We were lucky in that we had deep sand as a base.  However when it was to
grade I rented a plate compactor and while keeping the sand moist ran this
thing over the whole area until the sand was packed tight enough that it was
almost like walking on concrete.  The floor was 4" thick except in areas
where heavy equipment was to be placed and at the entrance where the hay
truck was to be pulled in.  We used 3500 mix and had it dry enough that it
almost killed the whole crew getting it in place and worked down.  We kept
the floor wet after the initial set for about a week.  And didn't put any
trucks or heavy equipment on the floor for almost a month.  We didn't use
any wire in the floor but did use re-bar in the footing and in the areas
where the floor was 6 inches thick.

The good news is (Can't see through all the junk) as far as I know there are
no cracks, none ever showed up while the floor was kept clutter free.  There
is also a ten by twelve foot apron in front that received the same treatment
and it also has no cracks.

In an extremely good article in one of the farm magazines told of all the
proper steps to avoid floor cracks, it also said that you can not put enough
steel in to keep the concrete from cracking if the base is not properly
prepared.

Just my feeling

1) Well compacted sand base
2) Good mix, rich in cement
3) Just enough water that it can be worked.  To many contractors want to
shoot the mud as far as possible as it comes out of the truck.
4) Keep the finished concrete wet so that it will cure slowly.
5) Don't put concentrated weight on the floor to soon.

H. L. Staples
McLoud, Oklahoma
USA

No matter where you go there you are.

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