Plastic

[willedoo]

A video on making roads from recycled plastic.

 

 

[facthunter]

What weight would that carry?  Nev

[willedoo]

I don't know Nev. As a comparison I've been using these plastic pavers in the driveway. They come in segments of 816mm x 612mm x 40 mm and interlock by clipping together.  The unfilled crush strength of the hollow plastic is 133 tonnes per square metre. Filled with gravel, the crush strength is 740 tonnes per square metre which would be the weight of ten B Doubles.

 

[spacesailor]

Scientifically. I

All plastics are ' none solid ' .

they will move as the vehicles passover it .

Bakelite was the most ' solid ' of plastics .

My Old " Smith's Selective " electric  clock hasn't moved for a " millennium. ( New Bakelite plastic ).

JUST NEED TO HAVE A NEED too plug it into 240 v AC.

spacesailor

 

Edited March 5 by spacesailor

[willedoo]

I've laid a small section of those surepave pavers as a trial to see how they handle water runnoff and erosion when it rains. Cost wise, they are not cheap. For a 2.4 metre wide driveway, the paver cost is around $100 per lineal metre of driveway, but still cheaper than concrete when filled with gravel.

[onetrack]

There's a better system than Surepave, it's called Rombus. Australian-designed, Australian-owned and Australian-produced, it uses recycled polyethylene filled with concrete. One square metre is capable of supporting 10.9 tonnes.

The quote I got last year was $34 a sq metre installed - about a 60% saving over a 150mm thick concrete pad, and equal to the 150mm thick pad, even though the Rombus grid is only 40mm thick.

All you need is a solid levelled and compacted surface to install it on, such as compacted road base, gravel or limestone. Rombus has the major advantage of flexibility, which eliminates the problem of cracking in concrete slabs.

 

https://rombus.com.au/

 

Edited March 5 by onetrack

[willedoo]

In all the Surepave data they only talk of a gravel fill, but I can't see why you couldn't fill it with concrete. Surepave recommend a maximum gradient of 11 degrees. Slope is a limiting factor on my driveway and it cuts out using hotmix. With a slope like mine, you can't get the compaction needed on hotmix. Rolling tends to squeeze it downhill. I like the idea of these plastic segments as you could do separate small sections at a time.

[nomadpete]

Pity about that

8 hours ago, willedoo said:

maximum gradient of 11 degrees

My present driveway is 10 - 15 degrees.

 

My previous driveway was 15 - 22 degrees. No contractor was interested - said that it was too dangerous to work machinery on it and compaction would be impossible. So I bought a Bobcat and did it myself. Then sprayed coal tar emulsion surface to stop it washing away when it rained. This was on the escarpment north of Twba.

 

The view was worth it.

[facthunter]

Without the underburden being specially reinforced there's NO way those weights would be carried.  Nev

[onetrack]

The sub-base has to be properly compacted, that's why I said compacted material such as road base - gravel, limestone, or the local preference.

The load stress on surfaces is shaped like a pyramid, as you go deeper into the base materials, the more the load stress fans out, and the less the pressure is, at depth.

So the Rombus grid and concrete infill blocks are taking the maximum stress levels, but below the Rombus grid, the pressure is reducing, the more you go downwards.

[facthunter]

Just check on the depth of reinforced concrete  which is required for runways and taxiways, at major Airports. It's metres thick and any dampness around  underneath will complicate that too..  Nev

[willedoo]

The unfilled and filled crush strengths of the Surepave of 133/740 tonnes per square metre would be determined by using a press until they crushed. A fully loaded bogie drive/tri-axle semi-trailer would have a ground pressure of a bit over two tonnes per square metre. The integrity of the sub-base is a big factor.

[old man emu]

1 hour ago, willedoo said:

The integrity of the sub-base is a big factor.

Yep. Just look at the way our rural highways break up, even without extended periods of high rainfall.

[willedoo]

4 minutes ago, old man emu said:

Yep. Just look at the way our rural highways break up, even without extended periods of high rainfall.

I remember quite a few years ago seeing the local council build a road. I was driving past on the side track one day and they were tipping loads of wet clay into one section. Clay is ok if it's left to bake out and combined properly, but this lot just dumped it in the road and kept on building. Sure enough, two weeks after the road was opened, that section had failed and they were digging it up again.

 

It was interesting watching the road builders redo the section outside my place 18 months ago. It's challenging as the road follows the top side of the flood plain and skirts the base of the hills. The hills are very porous, so there's a lot of sub-base water problems due to seepage from the hill. This time they dug the road out deep and put in a layer of stone the size of footballs or soccer balls. Once this was compacted it became a drainage honeycomb. The land on the other side is lower than the road so the drainage works. Over the rock went some geofabric, then the subgrade. If my memory serves me well, I think there was another fabric layer between that and the road base and bitumen. It would have been an expensive job, but hopefully should last well.

[onetrack]

"Metres thick" for runway concrete is a bit of an exaggeration, Nev. Boeing state that 17-20 inches (432-508mm) is an adequate depth for runway and apron concrete thickness for their biggest jets.

Once again, proper sub-base drainage and compaction of the sub-base is a major important factor - as well as the sub-base material selection.