CONCRETE ROAD SURFACES

[TimS]

The A5 realignment through Milton Keynes in the late 70s/early 80s it was built in two simultaneous contracts. One part had a concrete surface (since replaced) and the other had tarmac. I spoke to one of the contractors at the time and he said that there was a Government agreement (with some trade body or other?) that a certain percentage of new roads should have a concrete surface. Is this correct? I thought that I had seen something about it in the past on this site but cannot trace it. Any help appreciated.

[KeithW]

The A5 realignment through Milton Keynes in the late 70s/early 80s it was built in two simultaneous contracts. One part had a concrete surface (since replaced) and the other had tarmac. I spoke to one of the contractors at the time and he said that there was a Government agreement (with some trade body or other?) that a certain percentage of new roads should have a concrete surface. Is this correct? I thought that I had seen something about it in the past on this site but cannot trace it. Any help appreciated.

Well I have seen roads including part of the A1 where a concrete road surface was replaced by tarmac.

[varga]

The A5 realignment through Milton Keynes in the late 70s/early 80s it was built in two simultaneous contracts. One part had a concrete surface (since replaced) and the other had tarmac. I spoke to one of the contractors at the time and he said that there was a Government agreement (with some trade body or other?) that a certain percentage of new roads should have a concrete surface. Is this correct? I thought that I had seen something about it in the past on this site but cannot trace it. Any help appreciated.

Well I have seen roads including part of the A1 where a concrete road surface was replaced by tarmac.

A19 around hartlepool too, about 8 years ago I think it was that got a resurfacing.

[wrinkly]

The A5 realignment through Milton Keynes in the late 70s/early 80s it was built in two simultaneous contracts. One part had a concrete surface (since replaced) and the other had tarmac. I spoke to one of the contractors at the time and he said that there was a Government agreement (with some trade body or other?) that a certain percentage of new roads should have a concrete surface. Is this correct? I thought that I had seen something about it in the past on this site but cannot trace it. Any help appreciated.

I don't know anything about a percentage agreement, but around that time tender invitations for trunk roads on new alignments usually asked for alternative bids for either "rigid" (concrete) or "flexible" (blacktop) construction, and the rigid usually came in cheaper. Many concrete roads were built at that time, most of which have since been resurfaced in blacktop.

[WHBM]

I don't know anything about a percentage agreement, but around that time tender invitations for trunk roads on new alignments usually asked for alternative bids for either "rigid" (concrete) or "flexible" (blacktop) construction, and the rigid usually came in cheaper. Many concrete roads were built at that time, most of which have since been resurfaced in blacktop.

That is nearer how it was handled then. Bids were asked for both. A significant variant in the construction price was the distance of the site from the relevant concrete batching and/or blacktop coating plants, and different main contractors used different plants. The cost of haulage of the bulk materials from plant to site was a significant part of the overall cost.

It was also felt (and actually found) that this encouraged competitive pricing. If you had the only blacktop plant within range there would be no discounts offered to the main contractors. If you were up against a concrete surface instead there was now more need to be competitive.

[DB617]

I don't know anything about a percentage agreement, but around that time tender invitations for trunk roads on new alignments usually asked for alternative bids for either "rigid" (concrete) or "flexible" (blacktop) construction, and the rigid usually came in cheaper. Many concrete roads were built at that time, most of which have since been resurfaced in blacktop.

That is nearer how it was handled then. Bids were asked for both. A significant variant in the construction price was the distance of the site from the relevant concrete batching and/or blacktop coating plants, and different main contractors used different plants. The cost of haulage of the bulk materials from plant to site was a significant part of the overall cost.

It was also felt (and actually found) that this encouraged competitive pricing. If you had the only blacktop plant within range there would be no discounts offered to the main contractors. If you were up against a concrete surface instead there was now more need to be competitive.

That explains the regional variation much better than the simple 'some chief engineer preferred it' narrative. Interesting. That would be why there are so many of them in South Wales where I grew up!

[RichardA35]

The concrete option included the contractor mobilising and installing their own batching plant. The volumes and quality of concrete were beyond the local market capacities. The typical country town batching plant would mix and deliver about 40 cubic metres per hour delivered in mixer trucks and would be used to a more agricultural type of concrete rather than high slump high cement content C40 mixes. The typical concrete pavement train would be planned to run at a rate of at least 40-60 cubic metres per hour continuously for the whole day which was often 12 hours during the summer. The concrete was transported in hopper trucks either side tippers or moving bulkhead discharge with approx. 8 cubic metres per truck.
At the M40 Banbury to Gaydon section there were three batching plants - 2 pan mixers and a third split drum mixer -
one for the structures and general site concrete.
a second batched for the lean mix foundation and back up for the strutures
a third was for the concrete pavement (roadbase)

[Chris5156]

I don't know anything about a percentage agreement, but around that time tender invitations for trunk roads on new alignments usually asked for alternative bids for either "rigid" (concrete) or "flexible" (blacktop) construction, and the rigid usually came in cheaper. Many concrete roads were built at that time, most of which have since been resurfaced in blacktop.

I believe that the decision for one vs the other was made on the basis of the initial cost plus projected maintenance costs for a long period - 20 or 30 years. Concrete was typically more expensive at the outset but cheaper to maintain.

[Brenley Corner]

I clearly remember that when the M25 opened between J5 & J6 that the surface changed from concrete to tarmac at the county boundary between Kent and Sussex - the Kent section being concrete.
Could County road units at time (if they existed) influence construction specifications?

In a similar vein, the M25 throughout Essex was lit from Day 1.

[Bryn666]

I clearly remember that when the M25 opened between J5 & J6 that the surface changed from concrete to tarmac at the county boundary between Kent and Sussex - the Kent section being concrete.
Could County road units at time (if they existed) influence construction specifications?

In a similar vein, the M25 throughout Essex was lit from Day 1.

There will have likely been regional variations based on cost estimates and internal sifting processes - oop norf west here there were only two significant concrete sections of motorway construction and those were the M6 Preston to Lancaster (resurfaced in 1985, a mere 20 years after opening), and the then M63 from Roscoe's to Portwood (resurfaced in 2007 or thereabouts).

Given the abundance of red shale partially from the S Lancs coalfield mining by-products, this is also why Lancashire fell in love with having red hard shoulders. We had a lot of red road surfaces - Manchester in particular had many.

[Crimbo]

The M53 between junction 11 and 12 and the M56 between junction 15 and its end at Dunkirk are also concreted in the North West.

I often wondered why the M1 had a concrete surface between junction 43 and its end at Hook Moor instead of a tarmac surface when it was built and opened as late as 1999?

[DB617]

I often wondered why the M1 had a concrete surface between junction 43 and its end at Hook Moor instead of a tarmac surface when it was built and opened as late as 1999?

https://ukmotorwayarchive.ciht.org.uk/m ... -to-a1-m/

It appears that CRCP (continuously reinforced concrete pavement) was selected due to the instability of the heavily mined coal seams. A sensible choice. I wish the same had been done on the Gwent Levels section of the M4 (same decade of construction) as the carriageway has started to dip, probably due to the removal of the overburden of the toll plaza. Also, there are no residents in the immediate area to be afflicted by noise pollution. It appears to have proven a costly choice.

The above also notes that a section of CRCP had flexible paving ('blacktop') applied retrospectively due to noise complaints from a nearby community, something the people living in the new builds adjacent to the A4232 at Drope in Cardiff probably wish was a more common occurrence.

[Chris5156]

I often wondered why the M1 had a concrete surface between junction 43 and its end at Hook Moor instead of a tarmac surface when it was built and opened as late as 1999?

https://ukmotorwayarchive.ciht.org.uk/m ... -to-a1-m/

It appears that CRCP (continuously reinforced concrete pavement) was selected due to the instability of the heavily mined coal seams. A sensible choice.

Maybe, but in places it’s still a noticeably bumpy ride because the ground has settled since construction. There are some noticeable bounces between junctions 45 and 46 that have been patched and levelled multiple times but keep coming back.

The above also notes that a section of CRCP had flexible paving ('blacktop') applied retrospectively due to noise complaints from a nearby community, something the people living in the new builds adjacent to the A4232 at Drope in Cardiff probably wish was a more common occurrence.

There are several such patches, which come and go along the length of motorway at seemingly random points. They were installed according to proximity to nearby settlements.

[Bryn666]

A concrete surface everyone forgets about is the first stages of the Leeds IRR. Think this lasted into the 90s?

[MotorwayGuy]

The A2 Dartford Bypass opened in the early 70s with a concrete surface but apparently the surface was laid incorrectly causing a terrible roar at around 60mph. Luckily the section is mostly rural but it was completely rebuilt in the 90s to remove the concrete surface.

Interestingly the nearby A20 Swanley bypass which predates the Dartford bypass was also built with a concrete surface, however this has never been fully rebuilt and has just had a thin layer of blacktop applied over the original concrete, resulting in cracking. The section under the roundabout has actually had the blacktop ground off, revealing the original surface.

[Brenley Corner]

The section
url=https://www.google.com/maps/@51.3891878 ... ?entry=ttu] under the roundabout[/url] has actually had the blacktop ground off, revealing the original surface.

The section under the M25 dates from the mid-70s when the Swanley roundabout was created (the main Swanley Bypass being mid-60s); at that time concrete was used quite widely on new trunk routes across Kent. Its sibling the M25 between J5 and the Kent/Surrey border was also built in concrete and and opened 1979