Small Nylon Balls Between Paving Slab and Concrete Base

I can't find anything that indicates that it's standard practice.

I'd guess that somebody didn't feel like dealing with a level and a shovel, and used those as a quick way to level the pavers.

Thanks for the reply. I thought it might be something like that. But then the thread would become what are these small nylon balls normally used for/how come the guy who laid the path had a bag full of them?

My little search actually led me to a pretty cool concept, although it doesn't apply to your situation.

http://www.archiexpo.com/prod/hanson/reinforced-concrete-light-pre-slabs-with-balls-cobiax-59475-303342.html

Interesting: I wonder how much it would cost to mass manufacture slabs like this for use in paving.

I don't know, but it looks like they're making them right there in the UK. It's a great way to recycle plastic.

http://www.heidelbergcement.com/uk/en/hanson/products/flooring_and_staircases/cobiax/index.htm

If pre-cast paver it may be some type of test method. Seeing how far the ball settles on a vibration table. Two are used to show consistency thru out the slab. Just left in after.

Thanks. You've made me realise that I haven't looked at the bottom of the slabs to see if there are any corresponding marks/hollows. I'll probably have to wait 'til the weekend before I can look (too cold/dark in the evenings).

Could these balls have a more practical application. If the pavers were laid over old concrete using a wet mortar bed, could the balls be used to support the paver while the mortar set up. Also the balls could have a controlled crush property so that the slabs could be levelled by tapping the paver with a mallet? The balls would need to only support the pavers for a few hours. Just an idea!

Thanks. The concrete appears to have been laid at the time the slabs were laid. Not sure about the balls crush-ability: need to check at the weekend.

where the slabs green rather than cured when they where installed? possibly they are designed to prevent the slabs from cracking while the concrete settles and cures.

Installed in the manufacturing process, to act as "skids" making the moving and aligning of the plates in stacks easier and preventing the scratching or marring of the upper surfaces of the plate below.

Thanks. Is that a guess, or, do you have any inside knowledge?

Hi... I meant to have ended that statement with a question mark. It's a guess.

A reasonable guess too I think. Any guess is better than none at all, because at the moment I'm worried about replacing the slabs without really knowing what the balls were for.

If they've been there for years, why not just leave them?

I've had to remove some of the concrete bedding (I'm replacing fence posts), so, without really knowing what they're for/how they're used I don't know how to re-install them. I'm more puzzled than worried: they obviously have some purpose???

forget about the balls and install the posts in a normal fashion.

I think you were spot on.

I've now had a chance to look at the bottom of the slabs, and there are 4 indentations in the large slab two corresponding to the two balls I found in the concrete. So my guess now is that they are set in the bottom at manufacture simply to facilitate handling and transport. Whether they fall out on not when the slabs are being laid does not matter at all.

Maybe they're part of your seismic isolation system for the pavers. After all, you have to follow the codes....

Maybe is was an extension of this technoloby

Lessen the impact

By TAN CHENG LI
star2green@thestar.com.my

We are seeing more building materials that are less destructive to the planet.

HERE'S a phrase to remember: passive buildings. These offer a different approach in building green. Instead of reducing carbon emissions by generating alternative power, these buildings simply do not require much electricity in the first place because they are insulated from the heat through the right materials used in roofs and walls and are oriented away from direct sun.

As interest in green buildings grow, the industry is responding by introducing more green construction materials that promote passive cooling in buildings. Many have a green edge because they use recycled materials, are lighter, and provide better heat and acoustic qualities over normal bricks. Here are some of them:

Floor full of bubbles

One might be wary of stepping into a building where the floors consist of plastic balls but there are many such buildings in Europe and the United States. Bubbledeck, concrete floor slabs fabricated with rows of plastic balls encased within, have been in use in Europe for the past 15 years.

Bubbledecks are set to make an appearance locally next year as clay bricks manufacturer Brick Dotcom is building a factory in Bukit Berunting, Selangor, to produce the slabs under licence from its inventor.

Air-filled: With plastic balls encased within, Bubbledecks require less materials compared to conventional concrete slabs. They can also be used for roofs as seen here.

The balls create air pockets which displace the concrete, so less is needed. The air pockets also lighten the slabs, so less piling is needed in the building foundation. The balls range in size from 18cm to 39cm and will be made from recycled plastic waste. Despite the plastic balls contained within, the slabs are just as strong as conventional ones as there is a reinforced steel mesh within.

Getting the construction industry to have faith in building floors containing plastic balls might be a tough call but company director Gary Ng is convinced by the technology.

"That's why we are investing in the system. It can replace the present method of building slabs. Thousands of buildings in Europe are built this way. The advantage is not just in the slabs but in the whole structure because you will need less foundation, columns and beams. It will be cheaper as the whole building will be lighter so less materials are needed."