Lightweight aggregates like expanded/foamed glass will form that layer, though likely with a honeycomb of basalt fiber-reinforced concrete and a final reinforced concrete topping layer.
Ok thanks. So will the top layer of concrete on foamed glass be floating of a layer of melted ice? Won’t it gradually sink as more ice melts into denser water?
It’s unclear to me how thick this layer is supposed to be. Will building foundations go though it and be anchored in the pykrete below? Presumably it’s not possible to build building foundations in foamed glass?
will the top layer of concrete on foamed glass be floating of a layer of melted ice?
No, because ice has a thermal conductivity of 2.22 W/(m K) whereas foamed glass aggregate has a thermal conductivity of about 0.08 W/(m K) .
So the ice/foamed glass interface will stay quite cold and most of the temperature drop will happen across the foamed glass layer, assuming that it is a few meters thick or something. One issue is that in the very long-term you want to actively cool the upper layers of ice because the ice will start to develop a nonuniform temperature distribution.
The insulation may also be a type of concrete with foamed glass as the solid and a cement to fill the voids. This will then be topped with a much stronger layer of concrete. That concrete can be built on. Additionally that top concrete layer can be hollow for added strength and insulation. Think of a square grid of cells for the strength layer and a solid insulation layer underneath of the foamed glass ultralight concrete.
If you want to build a heavy building it may be better to just thicken that concrete topping layer than to penetrate into the ice, as the ice will be very cold (say, −40 degrees C) and you don’t want to melt it. But Maybe there are special materials that will allow this to work. Certainly NOT metals though.
Ok thanks. So will the top layer of concrete on foamed glass be floating of a layer of melted ice? Won’t it gradually sink as more ice melts into denser water?
It’s unclear to me how thick this layer is supposed to be. Will building foundations go though it and be anchored in the pykrete below? Presumably it’s not possible to build building foundations in foamed glass?
No, because ice has a thermal conductivity of 2.22 W/(m K) whereas foamed glass aggregate has a thermal conductivity of about 0.08 W/(m K) .
So the ice/foamed glass interface will stay quite cold and most of the temperature drop will happen across the foamed glass layer, assuming that it is a few meters thick or something. One issue is that in the very long-term you want to actively cool the upper layers of ice because the ice will start to develop a nonuniform temperature distribution.
Thanks. So will the building foundations be going through several meters of foam glass to the ice below?
The insulation may also be a type of concrete with foamed glass as the solid and a cement to fill the voids. This will then be topped with a much stronger layer of concrete. That concrete can be built on. Additionally that top concrete layer can be hollow for added strength and insulation. Think of a square grid of cells for the strength layer and a solid insulation layer underneath of the foamed glass ultralight concrete.
If you want to build a heavy building it may be better to just thicken that concrete topping layer than to penetrate into the ice, as the ice will be very cold (say, −40 degrees C) and you don’t want to melt it. But Maybe there are special materials that will allow this to work. Certainly NOT metals though.
https://www.sciencedirect.com/science/article/abs/pii/S2352710223008562