There is a huge difference today in labour costs between Britain (Western World) and Dubai / similar NE places that have cheap immigrants doing the work?
Once you have invested into a high-cost asphalt machine and two or three others, making an asphalt road costs less than paving a road in GB.
Investing into that machinery in the first place costs more than employing a few low-paid labourers in Dubai.
I also have another WAG to add: Dubai wants to attract tourists, so things need to look nice (that they are made shoddily because cheap labour isn’t worth the price is another aspect). A smooth paved pedestrian walkway just looks nicer than a boring asphalt road.
In GB, on the other hand, you want to make things easy for cars, so you pour asphalt or concrete roads which is quicker for dozens of miles than laying stones by hand.
I think it might be because the roads are built on sand. In the Netherlands pavers are used a lot for that very reason.
Also, it’s a lot easier to just remove some pavers if you need to work on pipes or wires laid under the road. You don’t need to tear up and then redo a lot of concrete or asphalt.
Pavers are great for ‘‘liquid surfaces’’, such as in Dubai.
The answer might be a hybrid.
They used them because there was no infrastructure to pave everything with concrete or aspahalt, but the pavers happen to be a great material for the type of soil in Dubai. Pavers are flexible. Dark asphalt is very hot. Concrete is an option, but plants and distrubution are needed, and concrete isn’t the best for that type of soil anyway.
Also… pavers have been considered upscale in the West, and Dubai has been known to lean towards things that are upscale.
You definitely don’t want to use salt water in your concrete mix, especially if it’s reenforced concrete. They would have to use fresh water to be up to code in the US anyway. Even brackish water wouldn’t work.
I’m pretty sure pavers last longer than concrete or asphalt. The reason we don’t use them in the developed world is that they are much more labor intensive to build, and thus expensive.
Remember the big earthquake in Turkey a decade or so ago. One set of apartments that collapsed, was because the contractor was cheap and took salty sand off a beach to mix in cement.
Not sure if it interferes with the chemical hardening process, or just corrodes the reinforcing rod, but all in all it sounds like it’s a bad idea.
Part of it is just tradition in that part of the world. You have numerous quarries set up to shape the things all over Europe and FSU, You have civil engineers who are familiar with the appropriate application, load ratings, underlayment requirements, etc. and workmen skilled at installation and repair. The stuff is heavy to transport so the source needs to be reasonably local. I think this is the biggest reason why cobblestone paving is rare in the US: There are few sources due to low demand, and low demand due to few sources…well that and high labor rates in the construction trades.
I would also argue that this is low skilled labor. Ending up with a flat, durable surface requires a fair amount of skill and experience, and the neat scalloped patterns they usually use require something of an artist’s eye to keep regular.
Large areas of black asphalt do tend to become furnace-like in hot climates, so that would be a good argument against it, even if there were a grade that did not become mushy in hot sun. Even in the US in the summer, stopping trucks can tear/wrinkle the asphalt, and motorcyclists have to carry or improvise plates to keep their kickstands from sinking into parking lots.
For Dubai, though, I would suspect that it is done because it appears classier.
I am a paver installation instructor, and despite USAs love affair with asphalt and cast in place concrete, segmental concrete pavers have been the first choice of pavements the world over except in the United States.
The OP makes a great point in that asphalt would never survive in the heat of Dubai, but we dont need to go there to to see the inefficiencies of asphalt as raise your hand if you have been held up in traffic because of road crew resurfacing a asphalt or concrete road? Asphalt is inferior to concrete in terms of road salt resistance, thermal buckling and freeze-thaw durability. But its fast and cheap, right?
Rigid concrete is fine, but over time will crack.
Concrete pavers on the other hand not only can be machine installed lowering up front costs, they can be pulled up and then reused if a repair must be made. They are also precast at 8000psi much higher than cast in place concrete. As a pavement, pavers/paving stones are the most superior pavement system on the planet today. They are the soccer of the paving world: accepted across the globe except the United States.
I must have missed this thread the first time around. I remember seeing a documentary about the construction of a bridge over the Mississippi River. There was a problem when their concrete trucks were delayed on the way to the bridge. Concrete has to be kept below a certain temperature before it’s poured. I think the mix plant even added some ice based on how long they expected the trucks to take on the drive to the site. But the delay meant the concrete got too warm and all those loads had to be dumped.
That might be a factor in Dubai. The extra effort to keep things cool probably adds to the expense of poured-in-place concrete.
Wow, that’s pretty neat. How are they to drive on? Even different kinds of flat asphalt highways in the US make your tires scream whereas other types are quiet like silk. I have to imagine these would positively roar at higher speeds.
Zombie thread and all but back in college I spent a summer working on a research project for Dubai. We were testing various asphalt mixes for them, using varying percentages of shredded rubber (old tires) added to the mix (improves elasticity and water resistance).
I’d mix up samples, compact them into a standard size, let them sit and then strength test them in a temp room set to average Dubai conditions, which were something like 40C (104F). It was hot as hell and what we found was that the majority of the samples started to disentegrate just sitting on the shelves, it was a real mess. I had to leave the temp room frequently to cool off and have some water.
I don’t know what the outcome of the project was (I was working for another grad student, I think this was part of his PhD thesis) but I can’t imagine that they ever used any of our blends for anything, they wouldn’t have been able to handle traffic. Maybe he recommended they use pavers
So I’m thinking the answer is closer to (2) in the OP - not necessarily the heat cycling itself, just the fact that it’s so damn hot period.
Cheap semi-skilled labor. Same thing goes for use of any type of granular building material (brick, stone, etc), when other less granular options are available.
In the US, material costs for paver stones isn’t that much more than for concrete, but installation is very labor intensive, and requires preparation that’s a bit different than for concrete and asphalt surfaces. It’s considered a specialty job, so there’s no economies of scale that would help reduce costs. Also, I’ve run into some resistance to textured pavement in general, not just pavers, from developers, public works officials, and others, for various reasons - snowplow drivers don’t like clearing it, women don’t like walking on it, etc.
