New road surfaces
Discussion
I live in Norfolk and the roads around here are finally being resurfaced. Whatever happened to normal, smooth tarmac. They are all being done with looseley stuck down grey stones, which leave huge amounts of dangerous loose chips everywhere and break up if so much as a bike goes over them. Just wondering what the thinking is behind this?
They haven't on all our other roads. What is worse, it is a national cycle route and I bet the surface isn't great for bike tyres. The road has huge dips on either side that swallow up car tyres like nobodies business and they haven't even bothered to fill these in. Next stop writing to the council I think.
Hello mate,
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Edited by WaspsNest on Thursday 6th August 21:22
They never came back to sweep the old one, stones built up on an inclined junction and cause a crash so I paid to have it swept at vast expense to myself and the stones have simply built up again. The new surface already has loose chippings on it and the odd pile of the stones in the road. It is a disgrace!
yeah you see what happens is that the stones come away and leave the polished surface of the spray underneath. This makes it very dangerous.
You should take some photos and send them to the authority who carried out the works. If it was subcontracted, then it will be under some kind of warranty and they should take some action, or at the very least put some signs up to warn people.
Cheers,
Brendan
You should take some photos and send them to the authority who carried out the works. If it was subcontracted, then it will be under some kind of warranty and they should take some action, or at the very least put some signs up to warn people.
Cheers,
Brendan
WaspsNest said:
Hello mate,
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Edited by WaspsNest on Thursday 6th August 21:22
GaryST220 said:
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.
That is high grip stuff. No idea of its actual make up I'm afraid!Great stuff when they lay it on a particularly testing corner
Not so great for the front tyres I imagine.John D. said:
GaryST220 said:
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.
That is high grip stuff. No idea of its actual make up I'm afraid!Great stuff when they lay it on a particularly testing corner
Not so great for the front tyres I imagine.GaryST220 said:
WaspsNest said:
Hello mate,
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Edited by WaspsNest on Thursday 6th August 21:22
However, coloured surfacing is not necessarily high-friction/anti-skid. Some is just to draw attention to it, such as the red surfacing in "no mans land" (between opposing carriageways, the ghost hatching). (edit - it's Bauxite, the high-friction material)
As a rule, if there is at least 50m in length of coloured, it's anti-skid. Less than 50m, it'll just be there to attract your attention. (HA/DFT guidance)
ETA surface dressing is normally used on rural roads, narrower single track roads, and roads with no definitive kerb to lay against. It IS still quite common, although the current culture of claiming for stone chips means that it is avoided by many LA's, even if they DO use the 10/20mph advisories.
Edited by Opulent on Thursday 20th August 13:36
Edited by Opulent on Thursday 20th August 13:38
Opulent said:
GaryST220 said:
WaspsNest said:
Hello mate,
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Edited by WaspsNest on Thursday 6th August 21:22
However, coloured surfacing is not necessarily high-friction/anti-skid. Some is just to draw attention to it, such as the red surfacing in "no mans land" (between opposing carriageways, the ghost hatching). (edit - it's Bauxite, the high-friction material)
As a rule, if there is at least 50m in length of coloured, it's anti-skid. Less than 50m, it'll just be there to attract your attention. (HA/DFT guidance)
ETA surface dressing is normally used on rural roads, narrower single track roads, and roads with no definitive kerb to lay against. It IS still quite common, although the current culture of claiming for stone chips means that it is avoided by many LA's, even if they DO use the 10/20mph advisories.
Edited by Opulent on Thursday 20th August 13:36
Edited by Opulent on Thursday 20th August 13:38
Do you know roughly, how much difference the "high grip" tarmac makes?
Edited by GaryST220 on Sunday 6th May 11:13
GaryST220 said:
Opulent said:
GaryST220 said:
WaspsNest said:
Hello mate,
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Edited by WaspsNest on Thursday 6th August 21:22
However, coloured surfacing is not necessarily high-friction/anti-skid. Some is just to draw attention to it, such as the red surfacing in "no mans land" (between opposing carriageways, the ghost hatching). (edit - it's Bauxite, the high-friction material)
As a rule, if there is at least 50m in length of coloured, it's anti-skid. Less than 50m, it'll just be there to attract your attention. (HA/DFT guidance)
ETA surface dressing is normally used on rural roads, narrower single track roads, and roads with no definitive kerb to lay against. It IS still quite common, although the current culture of claiming for stone chips means that it is avoided by many LA's, even if they DO use the 10/20mph advisories.
Edited by Opulent on Thursday 20th August 13:36
Edited by Opulent on Thursday 20th August 13:38
Do you know roughly, how much difference the "high grip" tarmac makes? I've never been able to test it, for obvious reasons.
I HAVE done a test before, by unplugging the ABS fuse in my car, locking my wheels on approach to the HFS-treated area, and as soon as you run on to the HFS, the wheels start turning, and you stop VERY quickly. (It was a closed road on freshly laid HFS, by the way - Wouldn't recommend it on open roads!). But if the difference was negligible then you can bet that the HA would soon drop it, rather than to promote it at every available bloody opportunity!
It does polish off though, through time and wear. It can also lift, so you'll get patches in the wheeltracks, where the standard surfacing underneath is exposed. That's when the road gets really bumpy and rough, and is normally a sign of overuse by HGV's. (Car's really do not wear the road at all, HGV's are hundreds if not thousands of times more detrictive to our roads.)
Sorry, that was a bit of a rubbish post. I'm a bit mullered from V and can't really think straight!
Edited by Opulent on Monday 24th August 21:30
Edit: Right, after sleep, and now sitting at my desk, I've done a bit of digging. High Friction Surfacing has to be approved by the HA, in a process called HAPAS (HA Product Approval Scheme). It can only be laid by a Contractor approved to work with that material. (Oh, and I got it wrong, the material is Calcined Bauxite, an artificial aggregate)
Anyway, I digress...
Standard straight line motorway should have a Polished Stone Value (PSV) of 50-55. The PSV is a friction factor, if you like.
(The techy bit says "The Polished Stone Value (PSV) test, must be carried out and is specified in BS EN 1097-8:2000. It requires six hours of polishing designed to produce a state similar to that which the aggregate would be subjected to under actual traffic when equilibrium conditions are reached.")
The maximum PSV of non-HFS aggregate appears to be 68, so I would suggest that HFS has a PSV of 70+, so a 40% increase over standard, asphaltic construction (as a minimum).
However, the texture of HFS means that it does not drain water very well, and it is very noisy, so guidance states it should only be used on tight radii bends and braking sections.
I'm boring the pants off you now, aren't I?
If you can get a copy, or find one on the web, HD36/06 is the Highway Standard that deals with the application of various surfacings. Edited by Opulent on Tuesday 25th August 07:29
Opulent said:
GaryST220 said:
Opulent said:
GaryST220 said:
WaspsNest said:
Hello mate,
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Edited by WaspsNest on Thursday 6th August 21:22
However, coloured surfacing is not necessarily high-friction/anti-skid. Some is just to draw attention to it, such as the red surfacing in "no mans land" (between opposing carriageways, the ghost hatching). (edit - it's Bauxite, the high-friction material)
As a rule, if there is at least 50m in length of coloured, it's anti-skid. Less than 50m, it'll just be there to attract your attention. (HA/DFT guidance)
ETA surface dressing is normally used on rural roads, narrower single track roads, and roads with no definitive kerb to lay against. It IS still quite common, although the current culture of claiming for stone chips means that it is avoided by many LA's, even if they DO use the 10/20mph advisories.
Edited by Opulent on Thursday 20th August 13:36
Edited by Opulent on Thursday 20th August 13:38
Do you know roughly, how much difference the "high grip" tarmac makes? I've never been able to test it, for obvious reasons.
I HAVE done a test before, by unplugging the ABS fuse in my car, locking my wheels on approach to the HFS-treated area, and as soon as you run on to the HFS, the wheels start turning, and you stop VERY quickly. (It was a closed road on freshly laid HFS, by the way - Wouldn't recommend it on open roads!). But if the difference was negligible then you can bet that the HA would soon drop it, rather than to promote it at every available bloody opportunity!
It does polish off though, through time and wear. It can also lift, so you'll get patches in the wheeltracks, where the standard surfacing underneath is exposed. That's when the road gets really bumpy and rough, and is normally a sign of overuse by HGV's. (Car's really do not wear the road at all, HGV's are hundreds if not thousands of times more detrictive to our roads.)
Sorry, that was a bit of a rubbish post. I'm a bit mullered from V and can't really think straight!
Edited by Opulent on Monday 24th August 21:30
Edit: Right, after sleep, and now sitting at my desk, I've done a bit of digging. High Friction Surfacing has to be approved by the HA, in a process called HAPAS (HA Product Approval Scheme). It can only be laid by a Contractor approved to work with that material. (Oh, and I got it wrong, the material is Calcined Bauxite, an artificial aggregate)
Anyway, I digress...
Standard straight line motorway should have a Polished Stone Value (PSV) of 50-55. The PSV is a friction factor, if you like.
(The techy bit says "The Polished Stone Value (PSV) test, must be carried out and is specified in BS EN 1097-8:2000. It requires six hours of polishing designed to produce a state similar to that which the aggregate would be subjected to under actual traffic when equilibrium conditions are reached.")
The maximum PSV of non-HFS aggregate appears to be 68, so I would suggest that HFS has a PSV of 70+, so a 40% increase over standard, asphaltic construction (as a minimum).
However, the texture of HFS means that it does not drain water very well, and it is very noisy, so guidance states it should only be used on tight radii bends and braking sections.
I'm boring the pants off you now, aren't I?
If you can get a copy, or find one on the web, HD36/06 is the Highway Standard that deals with the application of various surfacings. Edited by Opulent on Tuesday 25th August 07:29
What I want to know is, why are some dual carriageways completely yellow, and extremely noisy? You say guidance states it should only be used on tight bends and braking sections, so why a 30 mile stretch on a quiet dual carriageway? At 70mph my car sounds like a jet plane on take off.
P.S. Only hippy's go to the V festival, and thanks for contributing to the massive tail backs throughout the midlands. Cheers
GaryST220 said:
Opulent said:
GaryST220 said:
Opulent said:
GaryST220 said:
WaspsNest said:
Hello mate,
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Edited by WaspsNest on Thursday 6th August 21:22
However, coloured surfacing is not necessarily high-friction/anti-skid. Some is just to draw attention to it, such as the red surfacing in "no mans land" (between opposing carriageways, the ghost hatching). (edit - it's Bauxite, the high-friction material)
As a rule, if there is at least 50m in length of coloured, it's anti-skid. Less than 50m, it'll just be there to attract your attention. (HA/DFT guidance)
ETA surface dressing is normally used on rural roads, narrower single track roads, and roads with no definitive kerb to lay against. It IS still quite common, although the current culture of claiming for stone chips means that it is avoided by many LA's, even if they DO use the 10/20mph advisories.
Edited by Opulent on Thursday 20th August 13:36
Edited by Opulent on Thursday 20th August 13:38
Do you know roughly, how much difference the "high grip" tarmac makes? I've never been able to test it, for obvious reasons.
I HAVE done a test before, by unplugging the ABS fuse in my car, locking my wheels on approach to the HFS-treated area, and as soon as you run on to the HFS, the wheels start turning, and you stop VERY quickly. (It was a closed road on freshly laid HFS, by the way - Wouldn't recommend it on open roads!). But if the difference was negligible then you can bet that the HA would soon drop it, rather than to promote it at every available bloody opportunity!
It does polish off though, through time and wear. It can also lift, so you'll get patches in the wheeltracks, where the standard surfacing underneath is exposed. That's when the road gets really bumpy and rough, and is normally a sign of overuse by HGV's. (Car's really do not wear the road at all, HGV's are hundreds if not thousands of times more detrictive to our roads.)
Sorry, that was a bit of a rubbish post. I'm a bit mullered from V and can't really think straight!
Edited by Opulent on Monday 24th August 21:30
Edit: Right, after sleep, and now sitting at my desk, I've done a bit of digging. High Friction Surfacing has to be approved by the HA, in a process called HAPAS (HA Product Approval Scheme). It can only be laid by a Contractor approved to work with that material. (Oh, and I got it wrong, the material is Calcined Bauxite, an artificial aggregate)
Anyway, I digress...
Standard straight line motorway should have a Polished Stone Value (PSV) of 50-55. The PSV is a friction factor, if you like.
(The techy bit says "The Polished Stone Value (PSV) test, must be carried out and is specified in BS EN 1097-8:2000. It requires six hours of polishing designed to produce a state similar to that which the aggregate would be subjected to under actual traffic when equilibrium conditions are reached.")
The maximum PSV of non-HFS aggregate appears to be 68, so I would suggest that HFS has a PSV of 70+, so a 40% increase over standard, asphaltic construction (as a minimum).
However, the texture of HFS means that it does not drain water very well, and it is very noisy, so guidance states it should only be used on tight radii bends and braking sections.
I'm boring the pants off you now, aren't I?
If you can get a copy, or find one on the web, HD36/06 is the Highway Standard that deals with the application of various surfacings. Edited by Opulent on Tuesday 25th August 07:29
What I want to know is, why are some dual carriageways completely yellow, and extremely noisy? You say guidance states it should only be used on tight bends and braking sections, so why a 30 mile stretch on a quiet dual carriageway? At 70mph my car sounds like a jet plane on take off.
P.S. Only hippy's go to the V festival, and thanks for contributing to the massive tail backs throughout the midlands. Cheers
Without knowing specifics, I would imagine the noisy roads are concrete - they have the "look" of HFS, and are very hardwearing - but they have downsides. Their skid resistance is low, they don't shed water very well, and they are bad for spray. But, on a straight section, they last forever, don't tend to rut under HGV usage, and (probably most importantly to the HA) are relatively cheap (they can be a lot thinner than bituminous construction).
I know sections of major A-road where you can stand about 50m from the blacktop areas, and you can hear "roar" of the concrete carriageway 2 miles away more clearly than the traffic right in front of you!
Empty HGV's will lock wheels anywhere, they are generally mostly to blame for the skid marks on approach to junctions etc. I'm not a truck driver so I don't know exactly HOW easy it is to lock, or how real the risk of jack-knife it is. But in my experience (which is all I can go on), HFS is better laid than omitted.
HFS is known to shed water poorly, however the comparitively rough surface area allows more of the aggregate than normal to sit proud of any standing water. You can't make a road 100% safe - if there is a lot of water on the surface then you have to trust drivers to drive to the conditions - we can't promise that HFS will stop anyone from skidding, ever - but any extra grip is going to be better than none at all.
We engineers have to trust the Transport Research Labs and the HAPAS to specify a material, and they do the research - not good to "test" materials on a public road. I'm not saying it's perfect - there are always new mixes coming on the market - but we don't do a half-arsed job just to annoy people.
Opulent said:
GaryST220 said:
Opulent said:
GaryST220 said:
Opulent said:
GaryST220 said:
WaspsNest said:
Hello mate,
There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Do you know the purpose of yellow or red tarmac on approach to junctions, is it high grip tarmac or is the colour for aesthetic purposes? It seems to wear badly, causing a bumpy, uneven surface.There are several types of surface used dependant on the specification of road, and it's use.
The old stuff you're talking about is most probably a material called 'HRA' (Hot rolled Ashpalt) this was used with a bigger stone, and some binder to produce a tough, hard wearing surface. Lifespan was normally about 15-20 years on light traffic'd roads.
Nowadays, being green and all, the surface used is usually some form of SMA (Stone Mastic Ashpalt), lifespan of this is about 5-8 years, again dependant on drainage conditions of the road, and traffic volume. This stuff - when worn in, is really grippy, the tip is to wait until the wheeltracks turn a purple shade - then it's fully worn in.
This stuff is made from recycled tyres, bottles and suchlike (Well, the liquid that holds it together is, the stone is usually a 14mm cut).
You have other things which determine the surface type:
- Size of stone used (10mm, 14mm)
- Type of Binder used (Binder is the liquid that holds it together)
- PSV (Polished Stone Value...blah blah blah)
etc etc
Sorry for the long winded post, but i guess it's good to know what you drive on.
Take it easy
Brendan
EDIT: For being a long winded dumbass and missing your actual question.
The Grey stuff your talking about is called 'Surface Dressing'. Its a cheap way of refurbing an old surface....
They spray it with stuff called tack coat, then they spray lots of small stones on it and crush them down. Its like putting a new t-shirt over an old smelly one. They will come back and sweep it in about a weeks time once it bed's in (or at least they should do).
Watch this stuff though, its bloody leathal!!!! Normally not used nowadays.
Edited by WaspsNest on Thursday 6th August 21:22
However, coloured surfacing is not necessarily high-friction/anti-skid. Some is just to draw attention to it, such as the red surfacing in "no mans land" (between opposing carriageways, the ghost hatching). (edit - it's Bauxite, the high-friction material)
As a rule, if there is at least 50m in length of coloured, it's anti-skid. Less than 50m, it'll just be there to attract your attention. (HA/DFT guidance)
ETA surface dressing is normally used on rural roads, narrower single track roads, and roads with no definitive kerb to lay against. It IS still quite common, although the current culture of claiming for stone chips means that it is avoided by many LA's, even if they DO use the 10/20mph advisories.
Edited by Opulent on Thursday 20th August 13:36
Edited by Opulent on Thursday 20th August 13:38
Do you know roughly, how much difference the "high grip" tarmac makes? I've never been able to test it, for obvious reasons.
I HAVE done a test before, by unplugging the ABS fuse in my car, locking my wheels on approach to the HFS-treated area, and as soon as you run on to the HFS, the wheels start turning, and you stop VERY quickly. (It was a closed road on freshly laid HFS, by the way - Wouldn't recommend it on open roads!). But if the difference was negligible then you can bet that the HA would soon drop it, rather than to promote it at every available bloody opportunity!
It does polish off though, through time and wear. It can also lift, so you'll get patches in the wheeltracks, where the standard surfacing underneath is exposed. That's when the road gets really bumpy and rough, and is normally a sign of overuse by HGV's. (Car's really do not wear the road at all, HGV's are hundreds if not thousands of times more detrictive to our roads.)
Sorry, that was a bit of a rubbish post. I'm a bit mullered from V and can't really think straight!
Edited by Opulent on Monday 24th August 21:30
Edit: Right, after sleep, and now sitting at my desk, I've done a bit of digging. High Friction Surfacing has to be approved by the HA, in a process called HAPAS (HA Product Approval Scheme). It can only be laid by a Contractor approved to work with that material. (Oh, and I got it wrong, the material is Calcined Bauxite, an artificial aggregate)
Anyway, I digress...
Standard straight line motorway should have a Polished Stone Value (PSV) of 50-55. The PSV is a friction factor, if you like.
(The techy bit says "The Polished Stone Value (PSV) test, must be carried out and is specified in BS EN 1097-8:2000. It requires six hours of polishing designed to produce a state similar to that which the aggregate would be subjected to under actual traffic when equilibrium conditions are reached.")
The maximum PSV of non-HFS aggregate appears to be 68, so I would suggest that HFS has a PSV of 70+, so a 40% increase over standard, asphaltic construction (as a minimum).
However, the texture of HFS means that it does not drain water very well, and it is very noisy, so guidance states it should only be used on tight radii bends and braking sections.
I'm boring the pants off you now, aren't I?
If you can get a copy, or find one on the web, HD36/06 is the Highway Standard that deals with the application of various surfacings. Edited by Opulent on Tuesday 25th August 07:29
What I want to know is, why are some dual carriageways completely yellow, and extremely noisy? You say guidance states it should only be used on tight bends and braking sections, so why a 30 mile stretch on a quiet dual carriageway? At 70mph my car sounds like a jet plane on take off.
P.S. Only hippy's go to the V festival, and thanks for contributing to the massive tail backs throughout the midlands. Cheers
Without knowing specifics, I would imagine the noisy roads are concrete - they have the "look" of HFS, and are very hardwearing - but they have downsides. Their skid resistance is low, they don't shed water very well, and they are bad for spray. But, on a straight section, they last forever, don't tend to rut under HGV usage, and (probably most importantly to the HA) are relatively cheap (they can be a lot thinner than bituminous construction).
I know sections of major A-road where you can stand about 50m from the blacktop areas, and you can hear "roar" of the concrete carriageway 2 miles away more clearly than the traffic right in front of you!
Empty HGV's will lock wheels anywhere, they are generally mostly to blame for the skid marks on approach to junctions etc. I'm not a truck driver so I don't know exactly HOW easy it is to lock, or how real the risk of jack-knife it is. But in my experience (which is all I can go on), HFS is better laid than omitted.
HFS is known to shed water poorly, however the comparitively rough surface area allows more of the aggregate than normal to sit proud of any standing water. You can't make a road 100% safe - if there is a lot of water on the surface then you have to trust drivers to drive to the conditions - we can't promise that HFS will stop anyone from skidding, ever - but any extra grip is going to be better than none at all.
We engineers have to trust the Transport Research Labs and the HAPAS to specify a material, and they do the research - not good to "test" materials on a public road. I'm not saying it's perfect - there are always new mixes coming on the market - but we don't do a half-arsed job just to annoy people.
On a similar note, I am baffled by the local road works. They dug up the old surface, 300 yards worth and laid a temporary surface, they then dug up another 200 yards and laid a temporary surface. Then to my amazement they dug the whole thing up and laid a new temporary surface, now they are in the process of adding the final layer but they have started digging bits of that up too. This isn't a complaint but an observation, I'm just glad its getting done, I pass by 3 times during the day so I do notice their progess (it's been 4 full weeks since they started).
As for HGV's locking up, I'd hazard a guess at the brake balance being out on individual wheels. Many the times have I been behind a HGV and witnessed it randomly locking up one or more wheels - smells nice though
Maybe the truckers like trying to hang the tail out! 
(O/T but is the reason some trucks can lift one or two sets of their rear trailer wheels in order to increase the axle weight on the remaining axle, thereby reducing the tendancy to lock an empty trailer? Or is it to save tyre wear?)
As for the works near you, that sounds like someone's dropped a b
k somewhere. Temporary surfaces can be run on for quite a while before they need replacing, obviously more so on smaller, less trafficked (or rural) roads. Definately doesn't sound like good practice - and not doing us road-types any favours for our reputations! (Not that they were great to start with )
(O/T but is the reason some trucks can lift one or two sets of their rear trailer wheels in order to increase the axle weight on the remaining axle, thereby reducing the tendancy to lock an empty trailer? Or is it to save tyre wear?)
As for the works near you, that sounds like someone's dropped a b
k somewhere. Temporary surfaces can be run on for quite a while before they need replacing, obviously more so on smaller, less trafficked (or rural) roads. Definately doesn't sound like good practice - and not doing us road-types any favours for our reputations! (Not that they were great to start with )GaryST220 said:
While you're here....why is little effort made to ensure that man hole covers are level with the road surface? The average British road would be a lot better if mechanically sympathetic drivers didn't have to spend all day dodging these man made pot holes.
That is a pet hate of mine. I (or, the company/organisation I work for) spend a lot of money paying for the covers to be re-set to road level. If the covers are too high (or too low, for that matter) then they are subject to thousands of high-impact strikes every day. Over several years, this can damage the lids, and then you have to either dig them up, or get a machine (JCB etc) on them in order to get them up - which needs road/lane closures, reinstatement materials etc). (I assume you are talking about finished road level, rather than "raised ironworks" when the running surface has been planed off?)
Obviously, that doesn't take in to account the damage done to tyres/shocks/etc.
Often, we pay the "Stats" companies (BT, Cable companies, etc) to come in after the works have been finished to make good, if needed. Unfortunately, due to the compensation culture in this country, more effort is put in to reducing the trip hazards on footways. (Actually, it might be because it's more hazardous to peds than to a driver, if not the car, but I like to think it's because of bloody US-style sue-everyone tactics)
But yeah, once again, poor workmanship, lack of Clerk of Works making sure things are proper, cheapest bidder, etc. It's gonna sound like I'm going on the defensive, but I/we really do pick up on things like that and push the contractors to rectify. Unfortunately, local authorities tend to measure on length of roads surfaced, rather than overall quality.
I must admit, 95% of my works are on motorways or trunk roads - we have a very stringent safety audit policy, sometimes having 4 or 5 audits, both pre- and post-construction, which pick up on hazards like that. That doesn't happen on smaller roads, in my experience.
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