Pure freshwater ice has a compressive strength that varies as |temperature| in Celsius to the power 0.78. So once it gets to say −40 Celsius it has a compressive strength of around 60 MPa
...do you think all concrete has the same strength? Here is a paper with “concrete” that has 800 MPa compressive.
So once it gets to say −40 Celsius it has a compressive strength of around 60 MPa
If you care about creep, ice at −20 C shouldn’t have >1 MPa on it.
Measured compressive strength of Pykrete was much lower. It took me 10 seconds to find this paper, there’s some data for you. 20 MPa with 14% sawdust, but creep would obviously happen at lower stress.
If you care about creep, ice at −20 C shouldn’t have >1 MPa on it.
So what is your criterion for caring about creep? How does it vary with temperature? From the limited reading I have done it looks like you basically eliminate creep in practice at −100°C and you can put something like 30MPa on ice.
But I am not clear how sawdust/fiber affects this.
Here is a paper with “concrete” that has 800 MPa compressive.
Sure, but this material is presumably impractical. Practical, cheap concrete seems to be in this 20-40 MPa bracket.
But really, I don’t think this idea is particularly limited by the compressive strength of ice. I think the biggest threat is creep of the ice under load, and the difficulty of making an upper layer that covers the ice with good strength and also low thermal conductivity, and is also cheap at huge scale. I think it’s doable but it looks like this is the hard part.
Engineering toolbox lists it as 20-40 MPa
https://www.engineeringtoolbox.com/concrete-properties-d_1223.html
Pure freshwater ice has a compressive strength that varies as |temperature| in Celsius to the power 0.78. So once it gets to say −40 Celsius it has a compressive strength of around 60 MPa
https://ffden-2.phys.uaf.edu/311_fall2004.web.dir/heike_merkel/Slide4.htm
So sufficiently cold pure freshwater ice is in fact stronger than concrete, and I suspect that pykrete is even stronger but I cannot find good data.
...do you think all concrete has the same strength? Here is a paper with “concrete” that has 800 MPa compressive.
If you care about creep, ice at −20 C shouldn’t have >1 MPa on it.
Measured compressive strength of Pykrete was much lower. It took me 10 seconds to find this paper, there’s some data for you. 20 MPa with 14% sawdust, but creep would obviously happen at lower stress.
So what is your criterion for caring about creep? How does it vary with temperature? From the limited reading I have done it looks like you basically eliminate creep in practice at −100°C and you can put something like 30MPa on ice.
But I am not clear how sawdust/fiber affects this.
Sure, but this material is presumably impractical. Practical, cheap concrete seems to be in this 20-40 MPa bracket.
But really, I don’t think this idea is particularly limited by the compressive strength of ice. I think the biggest threat is creep of the ice under load, and the difficulty of making an upper layer that covers the ice with good strength and also low thermal conductivity, and is also cheap at huge scale. I think it’s doable but it looks like this is the hard part.