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Billcampbell
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If you had a pipe with a ID of 125 mil and was over 500 meters long filled with 5m3 of concrete what would the pressure be at the bottom
The pressure at the bottom of any vertical pipe is independent ( = not influenced by) of the diameter of the pipe.Billcampbell said:If you had a pipe with a ID of 125 mil and was over 500 meters long filled with 5m3 of concrete what would the pressure be at the bottom
It's basically an order of magnitude calculation, to show how it's done. Concrete, wet or dry, has a range of densities.gmax137 said:I wonder if the density might be different for the wet concrete (assuming the OP is interested in wet concrete being pumped through the pipe). There isn't much water in the wet mix so maybe it isn't significant.
I don't think that a practical situation could exist in which a vertical pipe of 500m could have concrete pumped through it. I guess a 500m pipe with a mainly horizontal run would be quite possible (I 've seen a 100m run with a rise of a few metres outside my house.) The pipe was only mild steel, afaics so I reckon it couldn't stand 500m head of concrete, - not to mention the problems of building a pump for the task. Also, is it not the case that builders of high rise buildings use cranes to lift the concrete? If it were feasible, piping would be far more convenient.nasu said:Is the pipe vertical?
Anyway, you will need the density of that concrete mixture.
Yes, you are correct. Since the internal pressure of the pipe is more than 1700 psi, it would take a very strong pipe to withstand that pressure.sophiecentaur said:I don't think that a practical situation could exist in which a vertical pipe of 500m could have concrete pumped through it. I guess a 500m pipe with a mainly horizontal run would be quite possible (I 've seen a 100m run with a rise of a few metres outside my house.) The pipe was only mild steel, afaics so I reckon it couldn't stand 500m head of concrete, - not to mention the problems of building a pump for the task. Also, is it not the case that builders of high rise buildings use cranes to lift the concrete? If it were feasible, piping would be far more convenient.
SteamKing said:Yes, you are correct. Since the internal pressure of the pipe is more than 1700 psi, it would take a very strong pipe to withstand that pressure.
http://www.constructionweekonline.com/article-7400-how-the-burj-was-built/1/print/In November, 2007, the highest reinforced concrete corewalls were made using concrete pumped from ground level to a vertical height of 601 metres. This broke the previous pumping record for a building of 470m on the Taipei 101 and the previous overall world record for vertical pumping of 532 metres for an extension to the Riva del Garda Hydroelectric Power Plant in 1994.
The concrete pressure during pumping to this level was nearly 200 bars.
When the record was set, a photocall was arranged and a distance of 601 metres was reported as the new record. However, it was discovered shortly afterwards that the concrete needed to go a little further and so an extension was added to move the concrete to 606 metres.
The mix was able to reach such astounding heights by running through a high-pressure trailer mounted pump (a Putzmeister 14000 SHP D). The concrete required approximately 40 minutes from the filling of the hopper to its discharge from the delivery line.
The concrete volume in the line amounted to approximately 11m³ with this installation height – meaning there was roughly 26 tonnes on the pump after every piston stroke – or five big elephants.
Over a period of about 32 months, the high pressure pump and two others delivered more than 165,000m³ of high-strength concrete, which, using our preferred unit of measurement, is about 66 Olympic sized swimming pools.
It's not clear what specific grade of steel you are talking about here.stedwards said:Not a problem. The yield strength of mild (low grade) steel is 63,000 psi. Ignoring the seam, 0.340" thick walls in a 5 inch pipe would burst at 1700 psi.
SteamKing said:It's not clear what specific grade of steel you are talking about here.
That is impressive. I wonder why it's not done for the thousands of modestly high rise buildings we see going up all over the UK?256bits said:It's been done - vertical pumping.
The record stands at 601 m. or just below 2000 feet.
( I just had to look it up )http://www.constructionweekonline.com/article-7400-how-the-burj-was-built/1/print/
Thoughtful question.sophiecentaur said:That is impressive. I wonder why it's not done for the thousands of modestly high rise buildings we see going up all over the UK?
The maximum pressure that concrete can withstand inside a pipe depends on several factors, such as the strength and quality of the concrete, the diameter and thickness of the pipe, and the type of reinforcement used. Generally, concrete in a pipe can withstand pressures ranging from 1000 to 5000 psi (pounds per square inch).
Concrete pressure in pipes is typically tested using pressure gauges or sensors that measure the force exerted by the concrete against the walls of the pipe. This can be done during the installation process or after the pipe is in use to ensure it can withstand the intended pressure.
If the maximum pressure for concrete in a pipe is exceeded, it can lead to cracks, leaks, or even a complete failure of the pipe. This can result in costly repairs, downtime, and potential safety hazards.
The pressure on concrete in a pipe can be controlled by adjusting the flow rate of the material being transported through the pipe. Additionally, ensuring the pipe is properly reinforced and of sufficient thickness can also help to control the pressure.
Yes, there are industry standards and regulations that specify the maximum pressure limits for concrete in pipes. These may vary depending on the type of pipe, its intended use, and the location where it is being used. It is important to follow these standards to ensure the safety and integrity of the pipe system.