Concrete
Fortress Material
<&recipe>Concrete is a very hard and resistant composite material. It's cheap to craft and makes for an excellent use for crushed excess <link;industrial_byproducts;slag;slag> produced by making steel.
<&brick>Concrete can be cut and assembled into various bricks and pillars using the §2Stonecutter§r.<br>
Concrete bricks have the same blast resistance as concrete, but can be disassembled faster than their solid counterpart, making them a good structural material.
<&partial>Concrete can be cut into slabs of varying thickness using a §2Stonecutter§r.<br>
You can also use that machine to make slabs and stairs of concrete, as well as concrete tiles which are smoother and more polished.
<&leaded>Leaded concrete is a reinforced material, which is highly resistant to explosions. It may also afford protection against radiation, if that is something you worry about.
<&liquid>Liquid concrete can be produced in a <link;mixer;Mixer> by combining half a bucket of Water with §2Gravel§r, §2Clay§r and §2two pieces of Sand§r. When emptied onto the ground it will spread like water, before solidifying after some time.<br>
Multiple buckets can be used to fill a larger area by placing it at key locations.
Note that if it spreads too thin, the liquid will dry into slabs instead of full blocks.<br>
If the concrete dries while a creature is standing in it, they will be trapped and unable to move. You can also fill a <link;chemical_thrower;Chemical Thrower> with liquid concrete in order to create improvised platforms or immobilize enemies.