Thread: The M1 in the rain..WTH- GC to Brisbane

Originally Posted by LandyAndy

Concreate may well be the way to go,there is no reason normal bitumen can be laid upon it....
... Andrew

Andrew

When they first did the Hornsby bypass part of the F3 north of Sydney, it was the concrete with the horizontal groove style, (which plays havoc with motorcycles), but the big complaint was from neighbours to the road and the noise of the semi-trailer tyres. The Greiner (Lib) Government soon had bitumen hotmix laid on top of the concrete base.

The hotmix over concrete still has less maintenance than hotmix over compacted road-base,because of the very stable nature of the concrete.

Diana

BTW: I thought that concrete cancer was the result of the "fast drying" concrete additives in the 1960's and 1970's - the nature of the drying left tiny channels through the structure where moisture could enter and attack the steel reinforcing? If you don't use those fast drying additives you don't have the same problem with the concrete cancer.

Concrete pavements have high initial cost but low ongoing maintenance costs. That said, when they eventually do fail, they are very high cost to rectify as you have to replace the whole slab. They are usually only used for very high traffic roads where the cost/benefit can be justified.

Water sitting on the pavement can be reduced by making the crossfall a bit steeper or cutting lateral grooves into the concrete. Grooves increase the noise though so are no good near residential areas.

You can put a bitumen surface (asphalt etc) onto concrete, you just have to be VERY careful how you bond it to the concrete. Usually the bigger problem is any cracking in the concrete will refect straight through the asphalt to the surface.

To significantly reduce vehicle spray when wet, you can get asphalt surfaces that are porus, the water basically flows through the asphalt mat (usually about 50mm thick) and runs off the road to the side "though" the asphalt. There is no water left sitting on-top of the asphalt to cause vehicle spray. It is very expensive but is used on motorways wher traffic vol is high.

Different colour linemarking (ie yellow) can also be used to make them more obvious when the pavement colour is light (ie concrete or some granite seals). Main problem is that the colour pigment in the paint ups the cost by at least 30%.

I would not have though concrete cancer would be a risk with concrete pavements. There is very little steel reinforcement used (if any) and there is generally a huge cover thickness, so water penetration to the steel to cause corrosion is generally not an issue.

I think the interesting thing is that over in Germany, the majority of autobahns are smooth, smooth bitumen (not even the typical cross-grooves to shed water). I don't recall having any trouble travelling on them in excess of 160kph in the wet or even in snow (with winter tyres of course).

The only concrete autobahns are in the far east where they were laid by the soviets to run tanks on. They are now nearly all replaced with new bitumen too.

Originally Posted by LandyAndy

Concreate is all the go in the US.

Andrew

Eisenhower built the US interstate highway network on the defence budget. Concrete was used so they could run their main battle tanks on the highways without transporters when/if the Russians, Chinese, Cubans, Vietnamese, whateverese invaded.

Originally Posted by Redback

Mate take a little drive down too Victoria, then you might appreciate the drivers in QLD

which explains everything given the number of victorians in Queensland!

Originally Posted by stevo68

G'day All,

Was going to write this up the other day but forgot, and notice I used WTH as opposed to "What the Fred" . Anyhoo, and someone on here might know why, but on the main stretch of highway, predominately the 110k zone, why on earth have they used that...what I can only describe as some sort of pale/concrete material as opposed to tar. Now the reason that I ask is that the other day and today, spent much of the trip, hands firmly gripped on the steering wheel and keeping a good distance from cars in front. Why? Well for those unfamiliar, in the teeming rain, you cannot see an F'ing thing. You may as well be driving blindfolded, the visibility is that bad.

Then, same rain, you hit a tar section and you can see quite clearly. I'm surprised there isn't more accidents. And whilst I am at it, frikin QLD drivers as soon as they hit the rain, jam on the breaks, great fun at 110k's an hr. The other day I thought there must have been an accident...but noooooo, it was a section of highway getting a bit of a downpour. Last not least are the moron's who do not turn on their lights in those conditions, one today almost had a black D3 up the jatzy......no lights on, like roger me silly . Ahhhh feel much better now, though would be interested in why they would use that sort of material when it is quite clearly hazardous in that type of weather,

Regards

Stevo

.....and the question is........Why were you doing 110 klm when "cannot see an F'ing thing. You may as well be driving blindfolded, the visibility is that bad. "

I dont really understand why concreate is so special for a tank to run on.
Roadtrains weigh in much heavier,and present a huge increase of weight per m2 over the tyres compared to tracks.
We have roadtrains running on most of our shire gravel roads,they hold up pretty well.Battle Tanks would do no damage at all!!!!
I dont wear the concreate for tanks idea,they are still building them that way.
Then,roadtrains are an Aussie thing.18 wheelers are the US norm.
I suspect its an employment issue.
The US pay real low for blue collar workers,and they have lots and lots of them.Our last Works Supervisor(tosser that he was) spent some time in the US in the road building game.He said that we get double what the US worker gets for the same job and they have to work their ass off for it!!!
Same for road transport,run semi trailers,pay them peanuts,no need for multiple trailers.
It would be real interesting to find the wage equivelent of jobs Aust/US.
We may discover the US is a hidden 3rd world country!!!
Andrew

Originally Posted by LandyAndy

I dont really understand why concreate is so special for a tank to run on.
Roadtrains weigh in much heavier,and present a huge increase of weight per m2 over the tyres compared to tracks.

It's because of the tracks. Concrete is much harder than bitumen - even though both may be able to handle the same gross weight, the metal tracks will just cut up the bitumen surface and fling it about.

Also road trains have nice, soft pneumatic tyres... lots of them, so the weight is spread over a much larger area. It's the weight per axle that's the killer.