[UncleSlacky]

Reminds me of "pykrete" which was also a potential construction material for ships (notably aircraft carriers) proposed during WWII:

https://en.wikipedia.org/wiki/Pykrete

[robotnikman]

Notably Project Habakkuk, which if built would have been the largest ship ever created.

https://en.wikipedia.org/wiki/Project_Habakkuk

[trhway]

back then it were large ships. Today the issue is building large Starships. How many would we need to move several millions people and various equipment to Mars. May be not ice - though ice should work if building in space (or on the Moon). And ice can be oxidizer if aluminum is used as fuel, so you just burn large part of your ship too. For building on Earth - something cheap and easy to shape. Say 3D sinter-printering from sand.