[TowerTalk] Hauling concrete & other topics
Fri, 5 Nov 1999 12:18:31 EST
In a message dated 99-11-04 22:30:37 EST, email@example.com writes:
> Anybody know a good way to get concrete off of the truck and into my
In addition to the manual method (ugh!) and the motorized wheelbarrows,
I always wind up using a pumper. There are 2 kinds - the snorkel type and the
truck or trailer mounted pumper. The snorkel is more expensive and is
designed to pump over something so it's kind of overkill if you've just got
distance to go. I just pumped 17 yards with one and it cost $363.00. That
includes travel time and their 3-hour minimum (he wasn't here for 3 hours).
A trailer-mounted pumper can pump up to 400 feet and runs about $15.00
per hour less. You can probably figure around $15-20 a yard to pump the
A tool I've found to be quite handy for larger holes is a concrete
vibrator. It's a flexible tube that you drop into the concrete and it
vibrates. This causes the concrete to spread by itself and results in a real
uniform pour. You don't have to shovel or push the stuff around yourself.
Rental is $25-35 and it's well worth it.
BTW it's been my experience that by the time you finish with a backhoe
excavating the hole, you're going to be 25-100% bigger than what was
originally called for. A crank-up base that called for 9 yards of concrete
actually took 17 yards. Another that called for 8 took 14. The problem is
that the backhoe isn't real precise and many times you've got sloughing in
the hole. The sloughing will bell out the sides and this is totally out of
your control. This is real common.
And BE CAREFUL. OSHA rules don't allow anyone in a hole deeper than 4
feet without shoring.
Installing a base in good, non-sloughing soil on a level grade is
pretty easy. When you've got a sloping grade and non-stable soil, it might be
best to bring in some professionals. They are going to charge $75-100 per
yard for their labor.
Another somewhat formidable part of this is the rebar cage. The specs
for it will be very specific; i.e. rebar size, grade, spacing, etc. For a
bigger tower, the rebar cage might weigh 2-300 pounds. My sequence is to
build the rebar cage (a couple of hours) in the morning and have the backhoe
show up around noon. After he's done excavating the hole, he can lift the
rebar cage into the hole. And in the case of Trylon Titan self-supporting
towers, he can also lift and suspend the bottom section with concrete stubs
in the hole while it gets tied to the rebar cage.
Cheers, Steve K7LXC
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