New type of road surface

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brianleach
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Joined: 14 Jul 2007, 2:10pm
Location: Winchester, Hants

New type of road surface

Post by brianleach »

I came across a new type of road surface in Hampshire over the Bank Holiday. It is on the B3046 through the Candovers.

I would describe it as really large chunks of stone embedded in tarmac. On the face of it it would seem to be a good piece of road, no potholes or other patches. However I was on 700 x 25's and it was like riding on mtb tyres. The drag was awful and it was very bumpy. I stopped for a snack and a drink in Preston Candover and my hands were almost numb. My intended route back was via the same road so I soon changed that.

Would be interested in the experience of others as I suspect it is a road used frequently by both Winchester and Basingstoke cyclists.
Valbrona
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Joined: 7 Feb 2011, 4:49pm

Re: New type of road surface

Post by Valbrona »

How can Britain not be a basket-case of a country with such poor roads? And plain dangerous for drivers because the level of contact between tyre and road is greatly reduced with surface dressings.
I should coco.
brianleach
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Joined: 14 Jul 2007, 2:10pm
Location: Winchester, Hants

Re: New type of road surface

Post by brianleach »

I have to say that for motor vehicles it would be fine. No potholes, no loose chippings (they are huge chippings held absolutely rigidly by the tarmac) and lots!! of grip. Once again I fear the surface was chosen purely for the benefit of motor vehicles with no thought for other road users.
Psamathe
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Re: New type of road surface

Post by Psamathe »

brianleach wrote:I came across a new type of road surface in Hampshire over the Bank Holiday. It is on the B3046 through the Candovers.

I would describe it as really large chunks of stone embedded in tarmac. On the face of it it would seem to be a good piece of road, no potholes or other patches. However I was on 700 x 25's and it was like riding on mtb tyres. The drag was awful and it was very bumpy.

Thinking aloud here, if the drag was awful on a bike I would have expected the drag to at least be higher for a motor vehicle (maybe not to the same extent but still higher than on a more normal surface). And even a slightly higher drag for a motor vehicle means increased fuel consumption, more greenhouse gasses, more pollution, etc. And slight for one car might have minimal impact, but given the number of vehicles around these days, slight can quickly be multiplied many times (i.e. slight x large number of vehicles = large impact). So, thinking aloud, I suspect there might be good environmental arguments against the use of such road surfaces.

But, I'm not basing my thoughts on fact, just supposition and welcome conflicting thoughts.

Ian
brianleach
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Location: Winchester, Hants

Re: New type of road surface

Post by brianleach »

You are probably right. My feeling was that once traffic had been over the road for a period of time the sticky out bits (a technical term you understand) which seemed to be causing the problem would be effectively knocked off leaving a smoother surface. In the meantime of course powered vehicles would not notice the increased drag.
iviehoff
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Joined: 20 Jan 2009, 4:38pm

Re: New type of road surface

Post by iviehoff »

Newly laid surface dressing is like this. When it is fresh, the chippings sticking up from the adhesive tar layer beneath them. But after a little while, the chippings get pressed into the surface and it flattens out, creating a nice surface.

We got a really weird new surface laid on a road near us, I'm pretty sure because it was cheap. I've not seen it before, at least not on a public road. It is almost the opposite, it has a very small chip size and mostly seems to comprise some sort of dark grey goo that was evidently sprayed on or the like. They didn't remove the old surface, rather they applied it directly to the existing surface, which had a lot of potholes and cracks in it. This goo seemed to fill all the old imperfections, and level out over them, even though the road is sloping, quite steeply for some distance. But it didn't look like it was rolled - maybe you couldn't. And so the overall effect is a rather uneven surface, but the unevenness is not related to the underlying unevenness, nor to the chips incorporated, and is on a much larger scale than the chips. Car drivers told me it felt pretty rough to drive over, but on a bike it was actually reasonably good. But it is clearly changing with time, heat and being driven over. Within about 10 days you could begin to locate the major underlying cracks it covered, for example.
Moodyman1

Re: New type of road surface

Post by Moodyman1 »

It's a brilliant bike surface in the wet or damp winter roads. Lots if reassuring grip.
brianleach
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Joined: 14 Jul 2007, 2:10pm
Location: Winchester, Hants

Re: New type of road surface

Post by brianleach »

That is the upside of course and it's certainly preferable to the loose chippings surface.
Mark1978
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Location: Chester-le-Street, County Durham

Re: New type of road surface

Post by Mark1978 »

There's a few like that around here, mostly bypass roads and the likes. The Consett bypass for example, an almost unridable surface, really really rough - even the Strava segment name is called 'rough', not to mention getting scared to death by lorries who don't slow down or move to one side. Whereas I've driven it in a car and it feels just like a normal road. Big fat car tyres with a massive air volume at about 30psi, massive suspension springs, and a comfy seat, of course a car is going to have a smoother ride than a bike.

I suspect the number 1 reason is cost, and secondly a rougher surface has better grip in wet or greasy conditions for cars.
brianleach
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Joined: 14 Jul 2007, 2:10pm
Location: Winchester, Hants

Re: New type of road surface

Post by brianleach »

Exactly my thoughts although this is a minor B road so lorries aren't an issue. 4 x 4s on the other hand!!

I'm no expert but it looks as though the surface will last a good while before any further work is required.
iviehoff
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Joined: 20 Jan 2009, 4:38pm

Re: New type of road surface

Post by iviehoff »

Having looked at some articles, I think that it was a slurry seal that was applied to my local road. http://www.pavementinteractive.org/arti ... rry-seals/

Although I couldn't see very much aggregate in the seal when initially laid, it seems the manner of laying it produced a thin layer of bituminous material over the top, exhibiting only a few small chips stuck to the top, when initially laid. After a couple of weeks, this has now either worn off or sunk in, and I can see the aggregate, being a typical road aggregate. But it is clearly different from the permeable aggregate that is most commonly used these days, and in particular it looks impermeable, which is a typical property of slurry seals. Putting permeable seal on this particular road is a disaster, because it is laid over an old concrete surface. So permeable seals just absorb water without being able to drain away, which then freezes and damages the seal when a frost comes along, which then converts to rapid pothole formation in heavy rain. So maybe, just maybe, if it doesn't crack up quickly due to the movement of the underlying concrete blocks, it may be a good solution.
brianleach
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Joined: 14 Jul 2007, 2:10pm
Location: Winchester, Hants

Re: New type of road surface

Post by brianleach »

It may be something similar but you wouldn't describe the protruding chips as small. The whole chip is visible, held together by tarmac making it very reminiscent of a rocky road chocolate biscuit. However again thinking about it I could see rain pooling in the gaps and if that water then froze it would produce a very slippery surface. Perhaps only good grip in the dry then. If I have to use the road again I'll try and get a photo as it is difficult to describe.
Psamathe
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Re: New type of road surface

Post by Psamathe »

iviehoff wrote:Having looked at some articles, I think that it was a slurry seal that was applied to my local road. http://www.pavementinteractive.org/arti ... rry-seals/

They use these a lot round me. With a pea single sized gravel. And it's horrible. All the holes and bumps stay as holes and bumps except now you can't see them because it's all the same matty colour. And gradually all the gravel accumulates towards the edge of the road and across junctions - so when you go to turn left, just when you are in your turn you hit loads of small shingle !!. And when you have to pull over for e.g. an oncoming tractor or car, you are suddenly riding in lose shingle (and for me this makes control somewhat harder, just as the car/tractor is passing!).

Ian
sirmy
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Joined: 11 Mar 2009, 10:53am

Re: New type of road surface

Post by sirmy »

You'll know soon enough if it's slurry seal as it will be potholed in a couple of months. It's really only fit for footpahts and ways (IMHO)
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CREPELLO
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Re: New type of road surface

Post by CREPELLO »

I'm a bit confused by the surface dressing definitions mentioned here :oops:
The new surface mentioned by Brian Leach, that's sounds very weird. If it was a new thick layer of tarmac, surely the large chippings would be rolled in, otherwise they would not stay put? Any chance of a photo if you pass near this stretch again?

Perhaps it's a new type of slurryseal with extra large chippings. This (standard chipping size) has been layed on two urban stretches of road near me. Although not as good as a new bed of tarmac, I found it surprisingly quick to ride on. It does looks a horrible mess when it first goes on, as if it was a cheap job done by cowboy builders. But it does seem durable, although I'm not sure how effective it's skid resistance is, as it does have a slightly slick look.

It also has the ability to effectively cover up surface defects from worn out chip seal, because of it's higher filler content. Obviously, it shouldn't be used on deeper defects, so I wonder whether it's capabilities are being abused by contractors? But its is nicer than chip seal IMO.

I didn't notice a wash of loose chippings as mentioned by Psamathe. I thought the chippings were an structural part of the mix, so would stay intact, unless the mix is defective.
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