Concrete Pump?
- Thread starter RonRock
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Pooh_Bear
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I think they are just a hopper to put the concrete in
and at the bottom of the hopper is an auger that pushes
the concrete into a pipe (like an extruder machine.)
The concrete has to be thin (more water) to be pumped.
A hose is hooked up to the pipe to direct the flow.
Pooh Bear
and at the bottom of the hopper is an auger that pushes
the concrete into a pipe (like an extruder machine.)
The concrete has to be thin (more water) to be pumped.
A hose is hooked up to the pipe to direct the flow.
Pooh Bear
speedy67
New member
I owned and operated a concrete pump for a few years. A Schwing 36M boom pump truck.
From my first-hand knowledge a concrete pump isn't something that a lay-man wants to build for himself. Now if you were to find one that needed a motor or some minor repairs or just some parts were missing, and you educated yourself about it, then yeah.
Contrary to popular belief, concrete needn't be extremely wet in order to pump, but the mix proportions must be such that there is enough lubrication (paste - water and cement powder) against the pipe and hose walls that the material can slide relatively easy. The sand gradation is critical to concrete's pumpability.
Flyash is a great assistance to aid concrete's pumpability, if you were to compare cement and flyash under a microscope, you would find that flyash particles are 10 times smaller than cement particles and cement is rougher than flyash. This relative smoothness helps tremendously in the lubrication. Flyash also gives concrete some desirable properties, it slows the chemical reaction and reduces the heat of hydration which reduces the inevitable shrinkage cracks and it ultimately makes a stronger concrete. up to 20 to 25 percent of cement by weight can be replaced with flyash, before the properties of flyash start negatively affecting the mix, mostly in terms of the finishablity of the concrete - it will tend to get too sticky.
For a DIY pump, perhaps a 'squeeze pump' best lends itself to a hobbyist to build, but they aren't concrete pumps, more like a mortar or grout pump, no large stone in the mix, just sands. the following link will take you to a site that discusses squeeze pumps the best: A Very Brief History of Concrete Pumps and What Monolithic Recommends
From my first-hand knowledge a concrete pump isn't something that a lay-man wants to build for himself. Now if you were to find one that needed a motor or some minor repairs or just some parts were missing, and you educated yourself about it, then yeah.
Contrary to popular belief, concrete needn't be extremely wet in order to pump, but the mix proportions must be such that there is enough lubrication (paste - water and cement powder) against the pipe and hose walls that the material can slide relatively easy. The sand gradation is critical to concrete's pumpability.
Flyash is a great assistance to aid concrete's pumpability, if you were to compare cement and flyash under a microscope, you would find that flyash particles are 10 times smaller than cement particles and cement is rougher than flyash. This relative smoothness helps tremendously in the lubrication. Flyash also gives concrete some desirable properties, it slows the chemical reaction and reduces the heat of hydration which reduces the inevitable shrinkage cracks and it ultimately makes a stronger concrete. up to 20 to 25 percent of cement by weight can be replaced with flyash, before the properties of flyash start negatively affecting the mix, mostly in terms of the finishablity of the concrete - it will tend to get too sticky.
For a DIY pump, perhaps a 'squeeze pump' best lends itself to a hobbyist to build, but they aren't concrete pumps, more like a mortar or grout pump, no large stone in the mix, just sands. the following link will take you to a site that discusses squeeze pumps the best: A Very Brief History of Concrete Pumps and What Monolithic Recommends
Pooh_Bear
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Thanks from me too.
Great info from you and from the link.
Pooh Bear
Great info from you and from the link.
Pooh Bear
speedy67
New member
I have heard of them being able to move larger aggregate, the rule-of thumb for a piston-type (high pressure) concrete pump is that the pipe/hose must be 3 times the nominal top size ofnte aggregate, but to be on the safe side, I subscribe to the theory of 4 times, so for 3/4" mix, it would take a 3" hose, but I used 4" slickline (the 'dead' system transport the concrete to the placing hose) myself, and a 3 1/3" x 40' long placing hose, that we would always move back when we broke back system. Any reducers should be as long as practical to reduce the pressure and possibility of plugging in the reducer. The reducer I had to go from 4" to 3 1/2" was 16" long and for 5" to 4" reducer, it was 36" long.
To pump a mix with 3/4" aggregate I would think you would need at least a 4" hose in the squeeze mechanism, a mix quite rich in cement powder and sand and likely minimal round rock as opposed to crushed. I don't think a mix that is normally pumpable in a piston-type pump would be pump in a squeezer, you'd need to cut back on the rock content and adjust the cement content upwards to account for the additional surface area imposed by the relaive increase in the mixes overall surface area.
Contrary to popular belief, you can get a strong mix out of round stone, although the stone needs to be consideraly cleaner in order for the cement to get a srong bond on the stone's smooth surface, as compared to the roughened surface of crushed rock.
There is a theory that you can actually get a stronger concrete with natural stone than crushed due to the fact that there hasn't been any stresses on the stones to cause micro-fractures within the interior of the stone to create the internal weaknesses that will fracture under the pressures imposed on the solid structure later. (this is the THEORY)
That being said, stone is actually a 'filler' in concrete. A single stone has much less surface area to be coated with cement paste than an equal volume of sand. You can get away with considerably less cement in a mix with larger stone and still acheive the same strength. the same is true for the amount of cement required to make the concrete 'pumpable'.
To pump a mix with 3/4" aggregate I would think you would need at least a 4" hose in the squeeze mechanism, a mix quite rich in cement powder and sand and likely minimal round rock as opposed to crushed. I don't think a mix that is normally pumpable in a piston-type pump would be pump in a squeezer, you'd need to cut back on the rock content and adjust the cement content upwards to account for the additional surface area imposed by the relaive increase in the mixes overall surface area.
Contrary to popular belief, you can get a strong mix out of round stone, although the stone needs to be consideraly cleaner in order for the cement to get a srong bond on the stone's smooth surface, as compared to the roughened surface of crushed rock.
There is a theory that you can actually get a stronger concrete with natural stone than crushed due to the fact that there hasn't been any stresses on the stones to cause micro-fractures within the interior of the stone to create the internal weaknesses that will fracture under the pressures imposed on the solid structure later. (this is the THEORY)
That being said, stone is actually a 'filler' in concrete. A single stone has much less surface area to be coated with cement paste than an equal volume of sand. You can get away with considerably less cement in a mix with larger stone and still acheive the same strength. the same is true for the amount of cement required to make the concrete 'pumpable'.
Defective
Platinum Member
I would have figured the problem with aggregate in a piston pump would be from stone getting stuck in the inlet. Kinda mess things up a bit.
Would an auger not work for some reason?
Would an auger not work for some reason?
speedy67
New member
Progressive cavity pumps are kind of a type of auger, most often they use an auger on the same shaft to feed material into the 'worm' part of the pump. the auger is open, that is to say, that it merely moves the material to the feed entrance of the progressive cavity area, it won't pressure up.
In my mind an auger won't build the pressure required to move concrete or any type of material even a few feet through a hose or pipe before it either binds or pressures out.
I have no experience with them ,but to my way of thinking, the pressure that a progressive cavity pump could build is directly related to the number of 'cavities' it has. (did that amake any sense?) a PC pump is only for pumping slurries of very small particle size, likely not even what I would consider a 'grout'....more like a neat cement mix - IE: water and cement only.
check this site for more info on concrete squeeze pumps: Blastcrete | Aggregate Mixing, Pumping and Spraying Equipment
In my mind an auger won't build the pressure required to move concrete or any type of material even a few feet through a hose or pipe before it either binds or pressures out.
I have no experience with them ,but to my way of thinking, the pressure that a progressive cavity pump could build is directly related to the number of 'cavities' it has. (did that amake any sense?) a PC pump is only for pumping slurries of very small particle size, likely not even what I would consider a 'grout'....more like a neat cement mix - IE: water and cement only.
check this site for more info on concrete squeeze pumps: Blastcrete | Aggregate Mixing, Pumping and Spraying Equipment
Defective
Platinum Member
Ah-Ha!
Should have thought of peristaltic pumps... (or should have looked at that earlier link.)
Solves all the issues at once. Simple, reliable, no worries about aggregates, easy to maintain, what else could you want.
RonRock,
If you have any kind of fabbing capabilities, you should be able to do this. Think used firehose... When it wears too much, just put in a new section. Of course, firehose may be a bit small. Any sources of larger, rugged hose out there?
Should have thought of peristaltic pumps... (or should have looked at that earlier link.)
Solves all the issues at once. Simple, reliable, no worries about aggregates, easy to maintain, what else could you want.
RonRock,
If you have any kind of fabbing capabilities, you should be able to do this. Think used firehose... When it wears too much, just put in a new section. Of course, firehose may be a bit small. Any sources of larger, rugged hose out there?
speedy67
New member
How about concrete pump hose? NAH, too easy!! 
You do want the best stuff in the highest wear area, the pressure is the highest there and the squeezing action will cause accelerated wear too.
Conforms is some of the best out there:
http://www.conforms.com/pdf/conforms/new_03/ProductCategoryPDFs-US/HoseUS03.pdf
Never count EBay out:
CONCRETE GROUT PLASTER PUMP HOSE!! 1.5" 2" 3" HOSE!!! - (eBay item 270154999611 end time Oct-12-07 15:51:31 PDT)
Another manufacturer:
Concrete Pumping Hose from JGB
Just Google 'concrete pump hose'
A word of caution, due to the high pressures involved and the potential for grave injuries and death, do not attempt the false economy of substiting any components not designed for the rigors of concrete pumping.
If you are capable of building your own concrete pump, don't cheap out.
My opinion is to hire a professional, concrete isn't cheap, doing it the second time is less cheap. And causing an injury is not worth any savings whatsoever. Hire a professional concrete pumper.
Hiring a crew do do a significant placement is money well spent, not to say that you can't shop price, but as in any time you hire a contractor, get references and check them out.
Anything over about 200 sq ft is more than you and a couple buddies can handle on a Saturday. It's best to get a pro, they do make it look easy....trust me, it's not.
You do want the best stuff in the highest wear area, the pressure is the highest there and the squeezing action will cause accelerated wear too.
Conforms is some of the best out there:
http://www.conforms.com/pdf/conforms/new_03/ProductCategoryPDFs-US/HoseUS03.pdf
Never count EBay out:
CONCRETE GROUT PLASTER PUMP HOSE!! 1.5" 2" 3" HOSE!!! - (eBay item 270154999611 end time Oct-12-07 15:51:31 PDT)
Another manufacturer:
Concrete Pumping Hose from JGB
Just Google 'concrete pump hose'
A word of caution, due to the high pressures involved and the potential for grave injuries and death, do not attempt the false economy of substiting any components not designed for the rigors of concrete pumping.
If you are capable of building your own concrete pump, don't cheap out.
My opinion is to hire a professional, concrete isn't cheap, doing it the second time is less cheap. And causing an injury is not worth any savings whatsoever. Hire a professional concrete pumper.
Hiring a crew do do a significant placement is money well spent, not to say that you can't shop price, but as in any time you hire a contractor, get references and check them out.
Anything over about 200 sq ft is more than you and a couple buddies can handle on a Saturday. It's best to get a pro, they do make it look easy....trust me, it's not.