Concrete

is extracted by Concrete Extractors on regolith rich deposits found all over the Martian surface. It is a basic building material and is used in a wide range of building types.

Description
On Mars, water is a rare and difficult to obtain commodity. As such, turning the Martian regolith into traditional, water based concrete was deemed unpractical very early on during the planning stages. Luckily, Mars is rich in another element with which a different type of concrete can be made into: sulfur.

Sulfur-based, waterless concrete is literally the foundation for every aspiring Martian city. Concrete Extractors placed on spots rich in sulfur in the Martian soil, dig up the sulfur-rich regolith and store it as ready to use mix. It is later transported and heated by our Drones on construction sites, turning it into strong and enduring concrete.

Surviving Mars
Concrete can be used to build Domes, Wind Turbines, and others. It's a fairly early-game accesible resource, until most deposits are depleted.

The Concrete Extractor will be a useful method until you research Excavator technology and Waste rock liquefying. It is recommended that you place a Dumping Site or two nearby.