3 ms·

Is bitumen a liquid or a solid? Technically, you can argue for either, but practically it seems to be very much a solid.

• jacquesm 9y ago
  Is water a liquid or a solid? It's a pretty simple question to answer if you know all of the parameters of the environment.
  • dotancohen 9y ago
    Not given "all the parameters of the environment" it is common to assume STP: Standard Temperature and Pressure. I think that's 20 degrees Celsius, 105 kPa of air pressure.
    • jacquesm 9y ago
      Well, under those conditions I would call bitumen a 'semi solid'. It is not hard in the sense of an actual solid, you can deform it but it definitely does not flow like a liquid.
      • dotancohen 9y ago
        That's a viscoplastic. Banana, chocolate, and dog droppings are some common examples.
        • jacquesm 9y ago
          Thank you for that term, I didn't realize there was an appropriate word to describe that state.
      • riffraff 9y ago
        AFAIU, it's a liquid, and it does flow, it's just that it flows so slowly it's almost impossible to notice https://en.wikipedia.org/wiki/Pitch_drop_experiment https://en.wikipedia.org/wiki/Pitch_drop_experiment
      • SAI_Peregrinus 9y ago
        Actually bitumen does flow. It's an extremely viscous liquid. There are a couple of pitch drop experiments[1] running, where bitumen is placed in a funnel and allowed to slowly flow. The experiment at the University of Queensland opened the funnel in 1930, 9 drops have flowed out since then, the last in 2014. The period between drops after air conditioning was installed seems to be in the 12-14 year range (only 2 drops have happened in that period). [1] https://en.wikipedia.org/wiki/Pitch_drop_experiment https://en.wikipedia.org/wiki/Pitch_drop_experiment
        • jacquesm 9y ago
          That's super interesting. I wonder if a vortex (a very very slow one) forms in the pitch in the upper container.
          • wbl 9y ago
            No, there is too much frictional loss.