"mook Johnson" wrote in message
...
I need to lift surface high enough so that it won't flood during heavy
rains. putting it 6" above ground level will insure that. The most I've
seen in that area is 2" of water during an extremely heavy downpour bfore
the water had a chance to drain off.

Just want to be safe.

I will rent a mixer for this job for sure!

Before you mix all that concrete, look at some alternatives.

Can there be a platform on blocks? 500 pounds is not much so building a
wood platform with a 2 x 4 frame and decking boards on top it will be
sufficient. I'd use four concrete blocks to support it all. Once the
concrete is in place, you have a very permanent slab. With wood and block,
you can move, modify, eliminate, add height, as needed.

The concrete slab will weigh about 1600 pounds. Do you really want to
handle that when something a couple hundred will do the job just as good?
--
Ed
http://pages.cthome.net/edhome/