looking at it through a screen made with sand, surrounded by buildings made with concrete. I could let you guess what's in concrete, but I suspect you're already catching onto a theme here.

and magnetic sand or ilmenite sand instead of common sea sand, concrete blocks can be obtained which have all the strength of the ordinary concrete blocks and which weigh, when immersed in water ...

A recent article published in Ain Shams Engineering Journal assessed the mechanical properties of sustainable sand concrete ...

This is led by the production of concrete, which is typically made up of about 25% sand. The problem when it comes to supply is that most desert or beach sand is unsuitable - desert sand is too ...