On 5/27/20 4:34 PM, Steve Maki wrote:
On 05/27/20 19:15 PM, Grant Saviers wrote:
Actually it is ok to pour concrete into a wet hole if the concrete is
pumped in from the bottom. The water rises right out. Not ok to drop
concrete into water. The mix plant, pumper and driver know how to
adjust the mix a bit.
Hmm - that's not my experience. When we (drillers hired by me) install
caissons for tall monopoles and self supporters with 30'-50' deep
caissons, they just dump the concrete in. They use temporary cylindrical
forms to prevent cave-ins, but pay little attention to the water down
there. These operations are always monitored by 3rd party engineering
firms. On the reports I usually see *freefall concrete placement*.
I agree, it doesn't rain much in SoCal, but I watched them place dozens
of caisson piers one rainy spring, and they just backed the truck up and
it came right out of the chute into the hole with the rebar. There was a
couple guys with the vibrators on a long flexible "hose" making sure
there were no voids. The water just spilled over the edge of the form
at the top as it filled. The hard part for the concrete crew was
placing the anchor bolts into the templates and getting it level.
(Of course, what we were bolting to the top of it wound up with the
holes in the wrong place, but that was our screw up - a drawing that
didn't clearly tell the fabricator which way was up. New holes created
on site)
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