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Author:
Alok Bhowmick
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2002-06-29 |
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I am going to use the polymer slurry to stablise the bore of 1.5m diameter piles, for a major bridge project in India. Can any one give me the following informations regarding polymer slurry :
a) What are the benefits of using the polymer slurry as against the conventional 'Bentonite Slurry'.
b) What 'precautiona' & 'checks' are necessary at site for ensuring correct and appropriate use of polymer slurry.
c) Is there any reduction in skin frictional capacity of bored piles, if polymer slurry is used?
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Follow-up:
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Author:
Hervé DUPLAINE
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2002-07-01 |
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a) The benefits of working with polymer slurry is that
1) you do not have to desand your slurry before concreting which is only interesting when your schedule of works is asking for more than 2 piles concreted per day.
2) if bentonite is not readily available, you will not have to transport as much material with polymer than with bentonite ( 30 times less roughly )
b) a polymer slurry must be treted exactly the same way than a bentonite slurry. You should work with a propduct which has a good list of references ( personnally I have always used GSTP from JF TECH ). You should not use polymer slurry in very permeable soils ( clean gravel for example )
If you are in sandy soils you might have to add some bentonite ( a few Kg per m3 ) to help the formation of the cake.
You will have to make sure that you have the necessary equipment to revert to bentonite mud if necessary.
Once the excavation of the pile is completed you should wait half an hour to allow for the soil particles in suspension in the slurry to sediment and then clean the bottom of the hole.
c) no, on the contrary, sometimes tension piles are specified to be drilled under polymer slurry. I believe there is no difference one way or another
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Follow-up:
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Author:
nagarajan
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2002-07-12 |
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hi,
to save cost and time polymer slurry is best for bored piles.it will enhance the production faster.
i am using polymer(from KB)for bored piles,dwalls for six years without any big problems.
advantage of using polymer:
no desanding required. just airlifting for 3o mins.
20 kg of polymer can replace of 2000kg of bentonite(1:200).
u can prepare slurry in big quantity in short period.say about 30 min to 1 hr.in bentonite u cannot do it easily
can u please tell me what type of polymer your are going to use?if u can mail me i can help u .
bye
naga
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Follow-up:
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Author:
gary chapman
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2002-09-09 |
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We are using polymer in preference to bentonite in large diameter bored piles in Melbourne Australia. We find it is much more environmentally friendly (easier to dispose of by just adding bleach and reverting the polymer to water) and much cleaner on site. It also saves time as you do not have to desand as much after drilling prior to pouring concrete.
Because the polymer works in a differnt way to bentonite, you do not get thick filter cake buildup on the pile walls, and thus skin friction is not downgraded as much.
On site you will need to keep a close eye on polymer viscosity and pH. The pH is critical, as is the mixing of the polymer to ensure you create long chain lengths
of polymer.
I would talk further with a polymer supplier to get the finer details of how to use it. Try contacting KB technologies who produce slurry pro in the USA for more details.
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Return
to subject 'Piling'
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Follow-ups:
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Subject:
Use of Polymer Slurry in Bored Piles 