How many kn? - New wacker plate

[kariba]

Hi all,

I moved from England to Australia and am currently in Perth on the West Coast. I'm buying a new compactor and was wondering if 16KN is enough force to compact sub base for driveways?

I would ask somebody here but almost every so called paver I have spoken to seems to think a sub base is not required in Perth because the sub grade is sand, everywhere. But if you take a look at the paving there is channelisation and humps and dips in most of the paving you see!

thanks in advance

[kariba]

Also there is no sharp sand or paving sand out here. Only washed sand or orange brickies sand. I have been using washed as there is a lot of clay in the orange sand. Any thoughts on that?

[Tony McC]

I'm probably asking to be cooked on the barbie, but the two leading experts for block paving in Aus are both ex-pat Brits. Sadly, one of them, Dr Brian Shackel, died about 12 months ago, but Simon....err...Simon, oh! what is his surname....I'll find it later, is still out in WA.

There are a small but loyal band of Aussie contractors who read the Brew Cabin occasionally, so maybe one of them can jump in with advice on the sand, but I will try to find Simon's details and ask him.

As for the plate compactor, the minimum recommendation in BS7533:3 (which is widely used in Australia and NZ) is for a 60Kn plate for class III and class IV pavements (drives/patios) and 75Kn for Class I and II (highways) - see this page

And those recommendations are for the bed and blocks. 16Kn will hardly tickle the sub-base!

[kariba]

thanks for the info Tony. So say a compactor with 16-20kn force would only be good for compacting beds and blocks even in light traffic areas? Even compacting the sub-base in layers at a time?

I did try an open the minimum recommendation but it takes me to a shop :rock:

[mickg]

I use the MBW GP2000 plate compacter which has a centrifugal force of 14.5kn

MBW GP2000

does the job what's required in my opinion otherwise I would change to another compactor

[Tony McC]

That "shop" is a page on this site linking directly to the BSI site so readers can buy the documents, if they so wish.

A 16-20kN plate is, in my opinion, neither use nor ornament. No - second thoughts - you could use it for compacting turf as it has slightly more wallop than the back of a spade.

[lutonlagerlout]

the best wacker I ever used was an old wacker
i dont know about KN and all that but i know it wacked the stone down really tight
bizarrely with different newer wackers some are good and some are bad
found rollers too big for domestic stuff > 30M2
if mick's wacker weighs 75kg i would have thought it does the job?
LLL

[TheRockConcreting]

i dont know about KN and all that but i know it wacked the stone down really tight

14.5 Kn is only 1.45 tonne, compacting a sub-base with this would mean it would be unable to take the weight of a large family car.

[TheRockConcreting]

Also there is no sharp sand or paving sand out here. Only washed sand or orange brickies sand. I have been using washed as there is a lot of clay in the orange sand. Any thoughts on that?

Try talking to the ready mix concrete firms they will be using 0/4 washed sand (paving sand) for the concrete.

[cookiewales]

i dont know about KN and all that but i know it wacked the stone down really tight

14.5 Kn is only 1.45 tonne, compacting a sub-base with this would mean it would be unable to take the weight of a large family car.

Mickg drives are all top notch you won't find any tram lines where cars go in and out its big hammer small hammer it's how you use them that matters more than kn tony I bought a old whacker of eBay a while ago with the drop down wheels it's a beast

[mickg]

I have tired to get a like for like with 3 companies compaction plates, they range from 11kn - 20kn, I don't know where you get the figures from that these vibrating plate compactors are not suitable for compacting anything other than turf or soil as all the compacters are similarish in weight and compaction and are used throughout the construction industry on sub base construction and the final compaction of block paving

wacker neusom
http://www.uk.wackerneuson.com/en....ta.html

MBW
http://www.mbw.com/products/plate2000.aspx

Belle
http://belle-group.co.uk/index.p....lang=en

could someone kindly explain why I am using a vibrating plate that's not suitable in your eyes yet the company I purchased it from say it is ?

[rab1]

And thats why a Bee cannot fly according to the laws of physics as we understand them

[kariba]

thanks for the feedback lads, awesome. so say micks compactor is 14.5kn or 1.45 tonne is that the force which is distributed over the area of the compactor base? while an average sedan may weigh around 1.5 tonne it will never spread the entire weight over an area the size of the compactor plate.

some very tidy work on your website mix. Is that herringbone max on the walkden job in manchester?

[mickg]

this one
http://www.crystalclearideas.co.uk/marshal....den.htm

its Marshalls Fairstone driveway setts, comes in 3 sizes 240 x 160 160 x 160 and 160 x 120
each block is bedded individually into concrete and it was pointed using Marshalls weatherpoint 365 a resin based jointing product

[Tony McC]

I don't know where you get the figures from that these vibrating plate compactors are not suitable for compacting anything other than turf....

The figures are taken from the British Standard, so if you want to dispute them, take it up with the committee.

It seems there's a disparity in what's being compared, and that may be partly my fault. The figures I quote for minimum force should have read kN/m², so, for example, if we look at the WackerNeuson DPS 1850 linked by Mick, it shows a centrifugal force of 18kN

However, the size of the base plate is only 600x500mm = 0.3m²

If we therefore multiply the centrifugal force by the inverse of the base plate area....

18 x (1/0.3)

...that gives a force of 60kN/m², which is in lkine with the recommendation of 7533:3


However, a plate of only 14kN, unless it has a small footprint, will not meet the recommendation.