Video: As you already know, ice is brittle stuff, which makes it bad for applications like stabbing fruit or beer cans. Add a little wood pulp, sawdust or, in this case, toilet paper, and you're cooking with a whole new substance called pykrete. Pykrete, despite mostly being ice, has some odd properties — notably a slower melting rate and a vastly increased tensile strength — that give it more practical uses that plain old frozen water. It can be poured into molds the same as concrete, but like wood it can also be cut and machined. The substance is named for English inventor Geoffrey Pyke who thought the stuff could be used to build an aircraft carrier during World War II.
Although there are pretty limited uses for a substance that has to remain at or below freezing, at least YouTuber Sufficiently Advanced has finally achieved his dream of building an ice sword.