How far can your concrete pumps pump? This is one of the most common questions we get asked. And most people are amazed to learn that, on an almost daily basis, we pump over 100 metres and regularly pump 200 and 300 metre pipelines.
For these contracts we send out a high-pressure pump; the concrete placing boom size is immaterial as it is not used when pumping a long line. We also send out a truck with the additional pipeline and linesmen to set up the line, break it back when the pour is completed and clean the line ready for the next contract. The standard ground line used in the UK for most operations has a 100 mm internal diameter. For long pipelines and with special concrete (lightweight aggregate concrete, steel fibre reinforced concrete etc), a 125 mm diameter line is used to minimise the pressure in the pipeline when pumping.
Many of the long concrete pipeline jobs that Camfaud carries out are in industrial areas or built-up environments where access for a concrete pump and truck mixer would be nigh on impossible. The Biddlesden Park job was somewhat different; the access problem here was being created by the soft lawn that swept down to the site of a new Summer House that was to be built. The most cost effective way of pouring the footings was to pump the concrete through almost 200 metres of pipeline.
Once the footing was poured, the pump operator set about cleaning the pump, and at the same time, the linesmen cleaned out the pipeline, stripped it back and loaded the pipes back on the truck. To clean out this long line, the concrete was forced out using compressed air.
At the pump end of the pipeline a sponge ball was inserted and a concrete wash out adapter was clipped in place. The placing hoses were removed from the discharge end and a ball catcher was attached. An air line was connected to the washout adapter and then, with all personnel standing clear, compressed air was introduced into the pipeline.
One of the linesmen followed the sponge ball as it travelled along the pipe, gauging its position by tapping the pipe with a hammer. When the pipe was two-thirds empty the air supply was closed and the remaining concrete is expelled by the pressure remaining in the pipeline. To ensure that the pipes were completely clean, a fresh sponge ball was sent down the line and retrieved at the ball catcher.
Please note that cleaning the line out with compressed air should only be carried out by experienced operators and only when there is no other practical way of cleaning the line.
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Pump: M24
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Customer: Gates & Co Ltd
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Site: Biddlesden Park
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Concrete Supplier: Hanson Premix
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Date: April 2006