We have water in the poles, place where to build bases in the huge lavatubes, and now is possible to build concrete in Mars with regolith.

Affordable housing in outer space: Scientists develop cosmic concrete from space dust and astronaut blood
>In their study, published in Materials Today Bio, a protein from human blood, combined with a compound from urine, sweat or tears, could glue together simulated moon or Mars soil to produce a material stronger than ordinary concrete, perfectly suited for construction work in extra-terrestrial environments.

>In an article published today in the journal Materials Today Bio, scientists demonstrated that a common protein from blood plasma – human serum albumin – could act as a binder for simulated moon or Mars dust to produce a concrete-like material. The resulting novel material, termed AstroCrete, had compressive strengths as high as 25 MPa (Megapascals), about the same as the 20–32 MPa seen in ordinary concrete.
>However, the scientists found that incorporating urea – which is a biological waste product that the body produces and excretes through urine, sweat and tears – could further increase the compressive strength by over 300%, with the best performing material having a compressive strength of almost 40 MPa, substantially stronger than ordinary concrete.
https://www.manchester.ac.uk/discover/news/affordable-housing-in-outer-space-scientists-develop-cosmic-concrete-from-space-dust-and-astronaut-blood/?utm_source=linkedin&utm_medium=social&utm_campaign=news