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Posted by marson on October 16, 2007, 6:43 am
On Oct 16, 4:22 am, alvinamo...@notmail.com wrote:
> On Tue, 16 Oct 2007 00:23:59 +0000 (UTC), d...@manx.misty.com (Don
>
>
>
> Klipstein) wrote:
> > alvinamo...@notmail.com wrote:
> >> I will be having a delivery this week of concrete. I am getting 3.25
> >> yards. Two and a quarter yards will make a 9 x 20 foot driveway
> >> extension in front of my garage. The other yard will go into a nearby
> >> shed to make a cement floor to replace the dirt floor, which is 6 X 12
> >> ft., plus a small pad outside the door from whatever is left.
>
> >> For the driveway extension the truck can drive right to it. But the
> >> shed is not accessible by truck. That one yard needs to be taken into
> >> the shed with wheelbarrows. I am trying to comprehend how many
> >> (average size) wheelbarrow trips will have to be made to carry that
> >> one yard to the shed. I am asking to get a rough idea so I know how
> >> many friends and wheelbarrows to have on hand. The delivery company
> >> said that their delivery guys cant spend a lot of time at one place,
> >> so I need to be ready to get the cement moved fast.
> >> I know someone is going to ask me what I mean by average size
> >> wheelbarrow. I dont know how they are rated, but the two that I have
> >> are the ones sold at most garden supply places, department and
> >> hardware stores for the average homeowner. My guess is the "bucket"
> >> is about 28" wide, 35" long, and 10" deep (of course the corners are
> >> rounded and the bucket tapers in at the bottom.
>
> >> My guess (and only a guess), is one wheelbarrow load can hold about
> >> 2.5 cubic feet, (without spilling all over the place), and a full yard
> >> of concrete is 27 cubic feet. So my guess is about 11 trips. Does
> >> this sound about right?
>
> > A 35 by 28 by 10 half-ellipsoid is 2.97 cubic feet, and in my experience
> >wheelbarrows are a little closer to conical than to that. A cone
> >(elliptical version as opposed to circular) of the same dimensions is 1.9
> >cubic feet. I would guess about 2.2-2.3 cubic feet.
>
> > Meanwhile, suppose the actual inside dimensions are 33 by 26.5 by 9.5?
> >That's 15% less volume! Sounds to me like 1.9 to 2 cubic feet now.
>
> > Another point - that wheelbarrow will not be level during the filling
> >and the transportation. I think it would be optimistic to fill it 1 inch
> >short of the top, and I think 33 by 26.5 by 9.5 then becomes at best 31 by
> >24.5 by 8.5, and that's with optimistic aggressive filling of the
> >wheelbarrow. That makes the volume 66% of the original figure (of 2.2-2.3
> >cubic feet), meaning about 1.5 cubic feet. Make that 1.6, because that
> >portion of the wheelbarrow gets a little closer to a half-ellipsoid and a
> >little less like a cone.
> > But this is still with filling the wheelbarrows so full that you have a
> >good chance of spilling concrete. I think more realistic is fill it 1.5-2
> >inches short of the top, roughly 1.3 cubic feet of concrete. A cubic yard
> >is 20-21 wheelbarrow loads at that rate. I may be erring a bit on the
> >conservative side - please post your actual results!
>
> > Now, another matter: How much weight to pour into a wheelbarrow?
> >Although the wheelbarrow operator only has to lift about 40% maybe 35% of
> >the weight of the wheelbarrow and the load, keep in mind how much a cubic
> >foot of concrete weighs. I asked a concrete mixer driver how much
> >concrete by cubic yards and tons his truck carries, and IIRC the answer
> >was 10 cubic yards and 20 tons - meaning a density of 2 tons per cubic
> >yard. I have read a few slightly lesser figures however. A ton per cubic
> >yard is 148 pounds per cubic foot.
> > The Wikipedia article on concrete says that the density is usually
> >around 150 pounds per cubic foot.
>
> > My experience suggests that if someone has to carry much over about 100
> >pounds, there is a good chance that things get wobbly. Beer goes only so
> >far to buy careful driving at best! I am guessing that it takes 10 pounds
> >of force to lift the handles of an empty wheelbarrow of above size,
> >leaving 90 pounds divided by the 35-40% above that I am guesstimating for
> >percentage of weight showing up at the handles. That means 225-257 pounds
> >of concrete. Divide by the Wiki figure of 150 pounds per cubic foot, and
> >that is 1.5-1.7 cubic feet.
>
> > At this moment, I would say probably 1.3 to 1.5 cubic feet per
> >wheelbarrow load, 18 to 21 wheelbarrow loads. Though I would not be too
> >surprised if everyone manages a "good mood chemistry" and gets it done in
> >15 trips - but be prepared for things to not work quite that well and
> >require closer to 20 trips.
>
> > Be prepared to accept the concrete delivery in a timely manner,
> >especially if you are not the last stop for the concrete truck. The
> >driver does need to empty the truck before the concrete hardens, and
> >concrete does not need air to harden. Concrete cures from the cement
> >ingredient (typically "Portland Cement") combining with water to form a
> >rock-like hydrated material.
> > Maybe even if you are the last stop the truck still needs to keep
> >rolling on a schedule - I suspect the truck may need to be rinsed out
> >before the residue hardens! (They say "cures" in that industry.)
>
> > Another thing that may help a little, at least gain a "brownie point",
> >when dealing with concrete people: Don't refer to concrete as cement.
> >Cement is the adhesive component of concrete. Cement roughly means glue!
> >Concrete is a mixture of cement, "fine aggregate" (traditionally sand),
> >and "coarse agregate" (this is often pebbles).
> > The basis for this is that most of the volume is pebbles with sand
> >grains filling much of the space between the pebbles, and pebbles and sand
> >cost a lot less than cement does.
>
> > - Don Klipstein (d...@misty.com)
>
> I just read all the replies on here. I know better than to fill the
> WB (wheelbarrow) to the top. I mixed some concrete for another shed
> by hand (with an electric mixer). I once overfilled the WB and it
> tipped over. What a mess !!!!
> I was originally going to mix this shed by hand, but since I am doing
> the driveway, it only ends up costing $40 more, because they charge
> $30 more per yard for loads smaller than 3 yards. So, by ordering 3
> yards, I am saving $60 on the first two. Or, in other words, 3 yards
> will cost $300, two yards would cost $260. So, I will be paying about
> $65 for that shed floor. (With that extra quarter yard). I can barely
> mix it for that, and it takes a lot of work to shovel all that sand
> and stone and make the mix right.
>
> Here's another idea that I got today. The shed is attached to the
> rear of my barn (it's a feed room). The truck can not get in the rear
> by the shed because the garage and some trees are in the way.
> However, if I close the gate to fence out my horses, the truck could
> drive to the front of the barn where there is a 9foot wide sliding
> door. I know the door is too low for the truck to enter, but their
> chute could come right thru the barn. They'd need a chute about
> 25feet long. The barn itself is 20ft wide so if they parked 2 feet
> from the door, ran the chute thru the barn, (at a slight angle), they
> could pour it right into that shed. The door comes off easily enough.
>
> Does anyone know how long the average chutes are on cement trucks?
>
> Thanks
> Alvin
Call your readimix company. They'll tell you--it probably varies by
model. A front discharge can reach 21 feet. A rear less. I'd look
into a conveyor truck. They aren't as versatile as a pump, but they
are cheaper, at least where I live. I just poured a three yard porch
patio with one--cost me about 125 bucks above the cost of the
concrete. They are good for small pours because the concrete and the
conveyor show up on the same truck.
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