Dear Members,

We are starting up concrete pouring for a rail slab in two 6km tunnels (2*25.000m3 in +-200m3 stages) in the port of Antwerp, Belgium, Europe. Pumping distances around 600m1 to max 700m1 after a vertical drop of 35m1 before entering the tunnel.

Equipment

- Main pump: CIFA HPC1410

- Backup /cleaning pump CIFA PC907

- Delivery line 5"/8mm with radius 1000mm bends and radius 550mm fall breakers.

- Pipe scissor 48m1 and delivery boom.

Anyone who can share their experiences with cleaning of a long delivery line with water? We are experiencing problems with separation of concrete and water. I would be glad to post some pics if I get some serious reactions on this topics

Thanks in advance

Put a ball (or several balls) between the water and the concrete. I would never just pump water after the concrete without a ball in between.

Where is this tunnel coming? Are they finnaly gona fix that terrible city ring road ??

forget sponge balls what you need is a rubber pig about 14 inchs long shaped like a cone with three cups behind as water pushes against pig it will hold the cups tighter to side of pipe giveing you less segregation

Did you already try with balls? You could also try the realy hard version ball. and there are also cone shaped sponches...

I would use a ball catcher basket and I would pour 3 gallons of bentonite solution infront of the rabbit

with air?

no air... water, the topic is "pushing concrete with water in long delivery lines"

I use a small homemade ball catcher basket that keeps me from having to fish my sponge out from the wash containment, works nice.

I think Kiwi has got it right use a pig

Kiwi.. Could you post a picture or any more details on this thing you talk about? I have no idea what you mean but I'm interested!!

no sorry have no pictures, sure someone posted one on here they will go though a normal bend i think we got them from cifa usa

Dipstick , Acme has rubberpig , Putzmeister have them... http://www.putzmeister.com.tr/ptr/data/PM_2300_GB.pdf See page 19 . http://www.polypig.com/ And probably many other company have them.

Ya I know it was a water topic just tryin to stir some POOP!

Thanks vasa. Now I know what we were talking about..

@dipstick: this project (railtunnel for the Port of Antwerp) is completely separate from the 'Oosterweel' project (road traffic tunnels for the closing of the ringroad around the city) , which will not be starting for the coming years (due to some green lefty action groups, who want to live near the city, but are all sick with NIMBY syndrome)

@all: we have already tried most of the things mentionned. A great problem is the wear on all sorts of plugs, which can be quite considerable in a long line. Beginning of next week we will try a combo: 2 sponge balls, plug of cement bags, sponge ball, pig, sponge ball, pig.

What would the effect be of adding bentonite or lubrication cement paste in front of the plugs?

BTW: another pour on the project: 25.000m3 of low strength mortar and 17.000m3 of steel-fibre reinforced concrete, both in one go

Thats heavy stuff.

Trying to push water that far is a recipet for disaster.Is there a specific reason you have to clean in that direction? Far more economical to use diverter valve and candy cane,blow back into mixer,using air.You can then wash pump into swimming pool,just a suggestion,do as you will.

Be nice to hear the outcome of this turkey

http://i257.photobucket.com/albums/hh201/kalvin1000/01_00020.jpg

Rubber pig and hard ball

Important for this to work line must be all one size.

Method

Stop pump

 Close gate valve

Reverse pump and disconnect

Wash machine

Insert pig followed by hard ball and reconnect line

Fill hopper with water and keep full

Apply half a stroke this will pressurise the fins on pig to create seal

Then open gate vale and pump flat out

When pig gets near to end your man will see slurry

Turn your pump down to idle and let pig and ball pop out

Reinsert ball and blow out water back into water tanks at pump end for reuse  

Cleaning may not be the correct term: it means both emptying and using the concrete on the spot and cleaning out the delivery line: 100m of line holds 1.2m3 of concrete, so for longer distances this is a loss of concrete. On ad daily production of +- 200m3 at 700m this represents +-4% of the concrete quantity. Furthermore,  with compressed air this would take too long and is far more risky, safetywise.

We are cleaning now with the following combination:

- Launching tube with rubber ball, 10 soaked paper bags, rubber ball, pig and rubber bal.

- Change diversion valve from concrete pump to 'water' pump

- Pump with water until combination reaches end of delivery line.

- Shut Valve at the end

- Mount the compressed air launcher with rubber ball

- Apply pressure (max available = 8 bars) and push back the water to the surface.

Indeed this is risky, but the exact procedure should be followed in detail. This has now worked for +-12 times already

What's a candy cane?

Just one question, what kind of delivery pipw are you using for 700m lenght?, I have a similar project and we are thinking in a SK delivery pipe. What's your oppinion?.

Thanks in advance

 A candy cane is a elbow poured into a conrete block with the one end of the elbow pointed up connected to a pipe of certain length with another elbow and a 8' hose attached at a heigth high enough to get the hose into the hopper of a mixer to blow back into.  The most important thing is  you have to chain it to the mixer so the air dosn't blow it back out and kill someone.

Who cares about the loss of concrete, probably some small minded job super that can’t see it is part of the deal.

The same guy that can’t understand you need 2 yard of grout to prime the line.

It is al part of the project, and calculated in front.