this is my first go on this forum so apologies if I'm covering old ground.
why don't we surface our motorways with concrete instead of tarmac,surely it,s more durable? I've just seen a programme on the box showing the construction of a freeway in Chicago where they used concrete for it's durability surely this must be better than relaying tarmac every few years?
the weather there must be similar to ours so that can't be the reason we use outdated tarmac.
Edited by Pugugly on 12/03/2008 at 19:38
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try driving up the A46 between Leicester and Nottingham , the concrete road is noisy but the b****umin expansion joints between bays is a pain (did i mean bitumen) at least tarmac is a continuous droll
Edited by Pugugly on 12/03/2008 at 22:32
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I'm trying to figure out the missing letters that tripped the swearfilter - spell 'em out spaced and I'll edit them in*
*if its decent of course
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"bloomin' "
b-l-o-o-m-i-n'
But then it looks like I spelt it wrongly anyway - must be the red stuff after a bad day at work - s-o-r-r-y
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sorry PU i was being fececious in my post, didnt work ... oh well
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I thought it was some sort of exotic metal....
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try driving up the A46 between leicester and nottingham the concrete road is noisy but the bitumen expansion joints between bays is a pain at least tarmac is a continuous droll
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I used to travel to the US on business and agree about the joints on the concrete Interstates; the engineers I dealt with there told me that suspensions and tyre sidewalls on US cars were specifically designed to allow for these expansion joints, hence the way tyre squeal is easily provoked and handling less than sharp on many models there.
I noticed that stretch of the A1 near Newark which used to be concrete slab has had a layer of tarmac laid on top; guess what, there are already dips over each joint where the tarmac has been hammered in by traffic, so its not actually better than the original concrete.
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"why don't we surface our motorways with concrete instead of tarmac,surely it,s more durable?"
Because it's incredibly noisy, rough and bloomin' awful for spray in the wet?
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Must be the red stuff - it wasn't even me!!
Abject and grovelling apologies.
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Noisy in the car ? You want to try living by a concrete road. Govt promised to do away with it on m/ways and trunk roads but then retracted the deal. Anybody who regularly drives the road from Chester via Wrexham to the A5 will notice the concrete stops at the Welsh border!
Mind you it lasts for ever - there was a section of the M6 round Stafford that must have done 25 years.
Edited by Bromptonaut on 12/03/2008 at 19:59
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If I remember correctly, the M90 north of Edinburgh is surfaced in ribbed concrete. As the poster above says, it's noisy and throws up a lot of spray.
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Concrete motorways are awful for reasons already given. The A1/M1 link around East Leeds which was concrete had to be resurfaced in tarmac after residents complained of the high road noise levels.
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residents complained of the high road noise levels
Maybe that explains why it is not a problem in the USA or elsewhere
1. either there just aren't too many people nearby to complain of any noise.
2. or the speed limits in those countries are much lower and so noise is not an issue
3. or the tyre rubber compounds are differently formulated to reduce noise.
Edited by jbif on 12/03/2008 at 20:52
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I think concrete has a lot less grip in the wet or dry, judging by some videos on the internet shot on concrete roads abroad.
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NO WAY.
I posted before on here about the noise from concrete.
Having got in from just driving from Newcastle to Luton, the one thing that made it tedious and noisy was those damn concrete surfaces, which was for most of the way !!!!!!
Apart from cost and life, what advantage is it over Tarmac
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NEVER concrete! Have you never driven on some of the newer motorway sections in the pouring rain? The tarmac soaks up the water like a sponge, there's hardly any spray until you get onto a concrete bit.
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I've just got back from driving down the A50 (many thanks for the suggestions on the Bedford - Wirral thread). I noticed the concrete sections had an uncomfortable rhythmic uneveness, seemed to be around ten Hertz at 70 MPH.
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There used to be some big signs in fields by the side of the A50 saying "Save our village from the noise - get rid of the concrete" or some such - don't know if it had any effect - that stretch from Uttoxeter to the roundabout just before Stoke has some incredibly noisy concrete sections (broken only by the silence as one goes over the tarmac which is used on some bridges).
Mind you, there is also a very noisy bit of tarmac on the M1 north of Northampton.
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On the M74 just south of Hamilton there used to be (might still be ) a stretch of concrete. We really only travel on that bit of the road if we are going away on holiday and heading south so the first hint of the noise was always met with a "we're on our holidays now" from the kids!
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Concrete motorway surfaces tend to be tiringly noisy and to absorb oil and rubber that then makes a slippery slurry when it rains after a long dry spell. It may be the way they are made here of course, with a washboard surface to provide braking grip (and make noise) and expansion joints (to make another, worse noise).
Doubtless elsewhere they have silent, grippy, everlasting concrete surfaces. But not here.
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But can you imagine what life would be like if the roads were made of concrete - no repairs for 40 years ( that's how long Chicago's lasted) - and therefore no more cones / men in yellow jackets leaning on them puffing their fags / traffic jams while we watch coned off lanes with nothing happening in them......
But surely in this day and age they can come up with a product that is just as durable, but less noisy? Or is it just that road makers don't want to because they'd be out of a job!
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The new concrete motorways in Germany are smooth no bumping no tracking lovely to drive on ,the secret is knowing how to build them and having the correct machinery.Building roads and bridges is something the Germans do well its like the dark ages in the UK.
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Section of the M6 between roughly the M54 junction and Stoke was changed from concrete to bitumen a few years back. I'd have said the concrete was the original, which speaks volumes for its durability. Assuming no noise issues for local residents, I'd vote for concrete if it avoids deformation by heavy trucks, potholes and the jams caused by relaying. Also, I found the M6 stretch I referred to less boring to drive on.
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Having been involved in tendering for motorway building in my earlier life , it was quite simple, The DoT specified the acceptable sub bases and surfaces and the cheapest price to the Main Contractor between tarmac and concrete got the job.
The problem of course is that as most people realise , if concrete surfaces are corrugated then they are noisy and if they are smooth they are slippery and do not clear water as quickly as tarmac. Also they do tend to crumble at the slab joints.
I would get rid of all concrete road surfaces if I had my way.
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Why is none of that true for German concrete autobahns.
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Because technology in Germany has moved on Andy.
The concete motorways we have which everyone complains about were built up to 40 years ago - the thinking was all about the bottom line and not about safety , noise or spray clearance.
Take a look at this link to see how these decisions were made in the late 60's and early 70's which was when I was involved in the business.
tinyurl.com/yqzyy8
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The noise problems of concrete have also been exacerbated by the recent trend for fatter, lower profile tyres and firm suspension. I remember driving an Escort Cosworth down the A34 just north of Oxford when that was concrete, and the din at 70 mph (honest) was incredible. As soon as we rejoined tarmac, it was like flicking an off switch - the noise just stopped.
That constant bliblip bliblip bliblip as you pass over the joints was a nightmare as well.
The other big issue with concrete is that white road markings are almost invisible against it in strong sunlight or rain, unless they paint a black box around each dot of the line, as they have on part of the southern stretch of the M25.
Cheers
DP
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I remember driving down the M1 stretches of concrete motorway in the 90's, how rough and noisy they were, and thinking, "why can't they pave over this with tarmac?".
I understand German autobahns used to be constructed with a transverse finish for skid resistance the same as in the UK.
It in only within the last 20 years or so the Germans have changed to a longitudinal lightly brushed finish, to reduce noise, and apparently this still provides good skid resistance.
The original German concrete autobahns were constructed to a high standard with high quality materials, and many were in use for 50 years, but in places they *did* crack due to joint spacing being too great, and spalling occured at joints.
Basic concrete slab construction is usually more expensive than asphalt paving (can cost 30% more per m2).
The UK is now starting to use porous asphalt as used in France, which gives less tyre noise than standard asphalt and reduces spray to an absolute minimum.
Edited by Rich 9-3 on 13/03/2008 at 13:46
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