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Thread: When crude oil runs out, how will roads be made and repaired?

  1. #31
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    Quote Originally Posted by Solfe View Post
    I have a book around here that was written in response to the 1970s oil crisis. I believe they listed $38 a barrel as unsustainable high. Once a problem reaches a certain point, things change unpredictable and you experience conservation effects.
    I recall a time back then the long lines at the gas station and the worry that we were running out of oil. About that time, sulfur-based alternatives to asphalt (AC; asphalt cement) were developed and tested in both hot mix and seal coat ("chip seal") applications. This would reduce the need for asphalt by over 90%, if it worked. The results were quite favorable, IIRC, and I drove on both applications for years. There was some less than desirable odor, though the chiggers were no longer an issue for those walking along the road.

    Swift's point (post #5) that asphalt can be recycled is very important because this greatly extends the life of our asphalt roads. Surface oxidation is minimal and the rest can be re-heated and re-layed. Asphalt plants can take about 20% of the old asphalt (millings, typically) and added into an asphalt plant's drum with avoidance of direct flame upon it. Asphalt roof shingles can also be an additive. There are some recyclers, usually with much lower production rates, that can take all the old asphalt. Surprisingly, the older asphalt roadways, when milled and recycled, can test better than the new mixes because of their higher composition of the better hydrocarbons (e.g. elastomers). Crumb rubber (tires, but virgin is preferred if allowed) can be used in small concentrations in hot mix, AC (e.g. AC5TR), and crack fill materials, but temperatures over 400F are required to handle it.

    The industry has coined the phrase, "Perpetual Pavement" to market this advantage over concrete, though its main use is with thick asphalt lifts (layers). It's no secret that the concrete industry has done a better marketing job than the asphalt industry. Often 8" or 10" of concrete road structure is compared to 8" of base (mostly crushed limestone in this part of the country) with 2" of hot mix pavement to serve as water protection and skid resistance. The concrete structure, compared to this limestone base design, is superior, especially for major roadways with heavy truck traffic.

    The asphalt industry has developed in the past 10 years or so a design that is much thicker with asphalt that is very competitive structurally with concrete and is also far more flexible as the subgrade shifts with both time and moisture variations.

    Regarding coal tars, they are coal-based, not really petroleum-based. These are excellent as a parking lot sealer since drips of gasoline and diesel have almost no effect upon it. I made the mistake of thinking a normal asphalt gear pump would handle it and it did...for one day. The next morning the pump was frozen and I think we had to replace it. Xylene and, perhaps, toluene are about the only solvents available that I know of that will flush lines and pumps that handle coal tar. As you might guess, these present real environmental issues. The coal tars used for sealing will burn your skin and the environmental concerns have banned its use in a number of cities.

    Fracking techniques will only get better and oil has been found at great depths. Asphalt roads will hopefully stay relatively inexpensive until we can travel without the need for conventional roadways.
    Last edited by George; 2017-Dec-24 at 06:13 AM.
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  2. #32
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    Quote Originally Posted by swampyankee View Post
    I hate the argument that fossil fuels will "never run out..." because it's false; obviously, they will, as the Earth has a finite internal volume and even more finite quantity of carbon in organic compounds that can be mined in the form of fossil fuels.
    It is entirely possible that fossil fuels will never run out, except in the pedantic sense that the earth will eventually be fried by the sun.

    Photosynthesis constantly produces new fossil fuels as algae sinks to the sea floor. If humans choose to speed up that process artificially, the resulting biodiesel will be much the same as fossil fuel, and could continue to be produced for ever.

    It is not true in this context that the amount of carbon available to be mined is finite, since the resulting carbon dioxide can be used as feedstock to make new hydrocarbons using the power of sunlight.

  3. #33
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    Quote Originally Posted by Robert Tulip View Post
    It is entirely possible that fossil fuels will never run out, except in the pedantic sense that the earth will eventually be fried by the sun.

    Photosynthesis constantly produces new fossil fuels as algae sinks to the sea floor. If humans choose to speed up that process artificially, the resulting biodiesel will be much the same as fossil fuel, and could continue to be produced for ever.

    It is not true in this context that the amount of carbon available to be mined is finite, since the resulting carbon dioxide can be used as feedstock to make new hydrocarbons using the power of sunlight.
    Running out of fossil fuels at an affordable cost and doing so with no consideration of them doing so was the basis of my note, not some absolute elimination. I used cobalt as an example, as the future cost and availability of that metal was of concern, so its users and consumers, including several governments, were actively investigating alternate metals, which seems to be exactly the opposite of the behavior regarding fossil fuels, where the attitude seems to be more like "God will provide."

    Getting alternatives to fossil fuels into service will take years, and the current attitude seems to mostly involve sticking heads into the sand.

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  4. #34
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    When I said "we are never going to run out", I meant for the forseeable future, say 100 years or so. Probably longer, but not actually forever.

  5. #35
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    Quote Originally Posted by swampyankee View Post
    Running out of fossil fuels at an affordable cost and doing so with no consideration of them doing so was the basis of my note, not some absolute elimination.
    I'm sorry to be pedantic swampyankee, but the basis of my comment that you reply to was your statement "I hate the argument that fossil fuels will "never run out..." because it's false; obviously, they will, as the Earth has a finite internal volume and even more finite quantity of carbon in organic compounds that can be mined in the form of fossil fuels." This is about absolute elimination, not affordable cost. The main constraints to fossil fuel availability are human stupidity and the energy of the sun. We can have a range of opinions on which of those two is more finite.

  6. #36
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    perhaps we shouldn't focus on pedantic points..

  7. #37
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    Brick could be used. In fact look at the Main Streets in some of the small towns in places like Kansas, they are paved with brick.
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  8. #38
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    Quote Originally Posted by captain swoop View Post
    Brick could be used. In fact look at the Main Streets in some of the small towns in places like Kansas, they are paved with brick.
    Ohio has a fair number of brick streets too. At one time, Southern Ohio had a lot of brick making (good clay supplies).
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  9. #39
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    Quote Originally Posted by captain swoop View Post
    Brick could be used. In fact look at the Main Streets in some of the small towns in places like Kansas, they are paved with brick.
    They are also newer projects, last 15 years, in larger cities as well to benefit tourism. Downtown San Antonio did a major project replacing old paved roads with a very tight-spec. brick road. [They required 1/8" max. transverse grade variance, which proved to be nearly impossible due to manholes, etc. The veteran contractor eventually went bust.]
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  10. #40
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    Quote Originally Posted by captain swoop View Post
    Brick could be used. In fact look at the Main Streets in some of the small towns in places like Kansas, they are paved with brick.
    yellow bricks?

    I suppose if there were enough cheap energy you could make glass brick roads.

  11. #41
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    Quote Originally Posted by Mudskipper View Post
    yellow bricks?

    I suppose if there were enough cheap energy you could make glass brick roads.
    I'm not sure the energy requirements are all that different.

    It is very dependent on composition, but typical glasses melt around 1500C. But they are malleable as low as 600C and it is possible bricks are made below the melting point (I'm pretty sure it is a mold process, but I don't know the details).

    Clay bricks are typically fired at 1000 to 1200C. But the energy requirements are going to very dependent on furnace technology details.

    I suspect glass is not a good road material.
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  12. #42
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    Toilets that are crushed have been used as a rock substitute for hot mix. From my experience, however, it made it harder to get density. [I think glass has been tried as well, but I don't recall the results.]

    But again, asphalt is easy to recycle over and over, which greatly extends our ability to maintain asphalt roadways for a very long time. Infrared heaters are used on roads in-situ, in the north primarily, to simply make rough asphalt areas pliable so that repairs can be made and without the problems associated with joints. Though problematic due to things like mesh and rebar, concrete roads can also be recycled by removing and running the chunks through a crusher to produce recycled aggregate for either new asphalt or concrete roadways.
    Last edited by George; 2018-Jan-05 at 03:11 PM.
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  13. #43
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    There is plenty of carbon on this planet, most of it in the form of carbonate rocks. Road surfaces, and a wide range of other structures, could be made using this carbon in a variety of forms. In its strongest forms such as nanotube, graphene and diamond, carbon is very strong and resistant to wear and tear.

  14. #44
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    Quote Originally Posted by eburacum45 View Post
    There is plenty of carbon on this planet, most of it in the form of carbonate rocks. Road surfaces, and a wide range of other structures, could be made using this carbon in a variety of forms. In its strongest forms such as nanotube, graphene and diamond, carbon is very strong and resistant to wear and tear.
    Yes, but road surfaces have to be cheap up front, at least in a democratic society, so some of the stronger forms may not work. They can't be too slippery, either...

    Information about American English usage here and here. Floating point issues? Please read this before posting.

    How do things fly? This explains it all.

    Actually they can't: "Heavier-than-air flying machines are impossible." - Lord Kelvin, president, Royal Society, 1895.



  15. #45
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    Quote Originally Posted by swampyankee View Post
    Yes, but road surfaces have to be cheap up front, at least in a democratic society, so some of the stronger forms may not work. They can't be too slippery, either...
    Roading could be a good way to store carbon to slow global warming. That might make use of bitumen derived from algae economic.

  16. #46
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    You can use bitumen, so long as you don't burn it.
    In thinking about materials, consider the expansion / contraction coefficients of these materials
    under a significant range of temperatures , as well as their permeability in the presence of severe pressure, temperature and the invasion of salt compounds . Also, black surfaces like bitumen
    heat up in the sunshine and help to remove ice and snow . Nice characteristics to have .
    There is enough to think about
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  17. #47
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    Quote Originally Posted by eburacum45 View Post
    There is plenty of carbon on this planet, most of it in the form of carbonate rocks. Road surfaces, and a wide range of other structures, could be made using this carbon in a variety of forms. In its strongest forms such as nanotube, graphene and diamond, carbon is very strong and resistant to wear and tear.
    Yes, and I wonder if carbon black could not be used. For instance, truck tire flaps (the rubber sheet hanging behind the truck tires) is just one example of a product derived from extracting carbon from old tires. Perhaps carbon from algae or even future, if we have to, CO2 scrubbers would help. This would be useful more for crack-filling the roadway cracks, which require greater elasticity to handle crack expansion during colder months.
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