road resurfacing, then chippings

loyatemu

Wicklow CC have recently resurfaced a number of rural roads in the area; as in proper resurfacing job, nice smooth asphalt properly laid, lovely work.

They've then come along several months later and laid tar and chippings on those very same roads - can anyone explain why they would do this? Obviously they regularly tar and chip badly surfaced roads anyway, but this approach of doing a proper relay and then chippings at a later date isn't something I can recall them doing before

(with my cyclists hat helmet on, chippings are unpleasant to ride on, very energy sapping, but also they tend to wear away very unevenly so you end up with a patchwork effect where some sections of the road have the old surface showing through and lots of bumps and ruts. They must be very hard on car tyres too, and they're noisy)

tjhook

With my drivers hat on, I dread passing fast cars on roads like that, with stones flying up at my car.

I can only imagine what it's like for a cyclist, to have stones flying towards them.

cnocbui

https://www.boards.ie/discussion/2058210930/road-resurfacing-then-chippings

They want the new road surface to develop potholes as fast as possible. In other countries, they scour the road network with vacuum sweepers to sweep up loose stone chips as these when pounded by heavy traffic can serve to break the road surface.

In Australia, I have even seen them spread crushed rock on heavily used roads in what appears to be a way of getting traffic to help break up a road surface they wish to remove and replace.

Dempo1

https://www.boards.ie/discussion/2058210930/road-resurfacing-then-chippings

I'd a giggled when I saw your post, here in Midlands, the CC seem to do things backwards. A few weeks back a section of road from my local village was cut off to all but local access for 4 days, we all thought locally, great ,the road being resurfaced.

Not a bit of it, on reopening the road ( 4km stretch) all that was done was fresh paint markings over pot holes & appalling surfaces . I suppose we should be grateful, its a road with many twists, turns , bumps, the new road markings might actually help us navigate and avoid the now highlighted dreadful surface and pot holes.

I Mentioned this to a local deli/ shop owner, he was delighted with the extra lunch time trade from the contractor's staff but was also amused to be Told, budget allocation had to be spent soon or next years allocation would be less. What better way to spend funds, freshen up paint markings on a crap road surface.

I'd heard stories like this before, couldn't believe it was true until I witnessed first hand, it is 🙄

loyatemu

https://www.boards.ie/discussion/comment/117953301#Comment_117953301

while the chippings are still loose, the greater risk is that you skid and slide off the bike.

But my main problem with this approach is the finished product is rough, noisy, energy sapping and over time results in an uneven surface.

I understand why the councils do it - it's cheap and covers potholes and other damage, but I can't understand why they would go to the effort of properly surfacing a road first, and then chipping it. Someone suggested to me it was to improve grip; but that doesn't seem to be a concern when using smooth asphalt on main roads.

https://www.boards.ie/discussion/comment/117953373#Comment_117953373

They did the same on the road outside my house a couple of years ago, newly painted lines everywhere. About 3-4 months ago they started marking all the potholes and rough patches. After a couple of days it rained so when they finished the ones from the start were already gone. Nothing's happened since.

I actually remember they did something similar on Pearse St. in Dublin maybe 10 years ago. It was in shite and one Monday morning I got to Pearse St. and all the lines were freshly painted and at first glance the road looked great. About 3 years it was actually resurfaced.

ednwireland

yes it hurts getting pinged by loose chippings when people speed past cyclists - thank god i normally wear eye protection !

i beleive the tarmac they use on main roads is a very different beast to what is used on side roads which is why they chip side roads after tarmaccing.

ah spending budgets - i wondered why loads of road markings had suddenly appeared, a stop sign appeared on our road and its never had one !

Pete2k

Supposedly for better grip in icy conditions from what I've heard. Depends on the council in each area... Roscommon and Galway generally don't do it, Mayo seem intent on it tho

loyatemu

https://www.boards.ie/discussion/comment/117953593#Comment_117953593

yes, as it happens I was in Achill over the summer and I noticed they'd done an unusually good chipping job on the main road through the island - very even with a tidy edge.

Chris_5339762

Still the old contracted lad with a trailer of fresh tar down my road.... not even a roller to flatten it down afterwards so you can imagine how long it lasts.

ballinadog

Basically there are different grades of "Tarmacadam". On most of the main roads around the country, they are usually made up with a number of different layers. Down deepest (called the Sub Base) there'd be a layer of Clause 804, which would be gravel sized stones to me and you. Next would be the Road Base, a thick layer of DBM (Tarmacadam) of say 6 inches thick. This is a cheap material, whereby it uses cheap stone (no high grip characteristics for example) and also uses a cheaper bitumen to hold the mix together. It can be cheap and cheerful as it'll never have a wheel travel directly on it. On top of this, comes the Binder Course or Regulation Course. It would generally be made up of the same DBM material as the Base layer, except it wouldn't be as thick (typically 2 inches), but its purpose is to further smoothen out the carriageway prior to the final layer. The final layer is again typically two inches thick but varies greatly from all that went before. As the tires actually make contact with this layer, it has to have what's called a high PSV chip, which means over time it doesn't polish and become slippery for example. It also has a significantly higher grade of Bitumen within the mix to hold the material together for longer. There are a good few more characteristics as well (say on Motorways where noise of the chips etc are taken in to consideration) but long story short it drives the price of this final layer thru the roof.

Now, for years all the local side roads around the country were surfaced with just "Tar & Chip" which was basically a thin layer of bitumen spray applied to the road, and then the "dear" high psv chip dropped on to same and that was it. The road gained its strength & stability over time by this process being repeated over the decades. There was never any "sub substructure" work done to the base of these roads from the get go as ya have to remember when these roads were created 40/50/60 years ago, the traffic levels paled in to insignificance to todays levels.

Now, re the opening post. In the last say 5 years, the councils have essentially amalgamated the two processes together. So for a finish, it looks a cheap and cheerful job as we are left with the old tar & chip, what has really happened is the council have actually jumped in at the regulation/binder layer in the first process. They've used a decent DBM material to regulate the existing road, fill potholes etc but then rather than get caught for the real expensive Surfacing course, they've plumped for the cheaper tar and chip on top to give the final layer the required properties. Nine times out of ten this is generally plenty good, as the roads they tend to carry this out on are minor/secondary roads and so wouldnt be carrying as much traffic as the National/Primary roads