Ferrocrete

Ferrocrete is a specialized building material used across the Inner Sphere and beyond. It was initially designed for use in fortified or strengthened applications such as bunkers, airfields, spaceports, municipal, government/military facilities and roads for BattleMech traffic. With access to more and more planets during early expansion phases, lower grades became inexpensive enough for average civilians to afford and therefore it became commonplace anywhere humans lived, worked or visited. Where normal concrete has its own standards for compressive strength (PSI) and density for general civilian, commercial and military roads, a much denser and stronger version is needed for heavier vehicles and BattleMechs so that treads and heavy 100+ ton footfalls do not 'stamp' or cause the material to sink-in under load. Higher grades are also used to cost-effectively armor structures, similar to how Ferro-Fibrous Armor protects BattleMechs, but not as strong or expensive per ton.

Ferrocrete is essentially an advanced type of very dense concrete formulated to be much stronger than the highest grades of standard concrete. Ferrocrete compositions contain no air gaps and have a defined compressive and lap-shear strength for each Grade. Grades 1-7 are standardized across the five Great Houses of the Inner Sphere, as well as ComStar, with Grade 1 being the weakest and cheapest to produce, as well as the most forgiving with regards to gel and set times. Typically composed of a mix of one or more synthetic binders, resins, epoxies, elastomers and whenever possible -or if required by the application- lengthy or large pieces of recycled metallics and/or alloys, ceramics, sand (only as a filler), minerals, manufactured carbon structures and stone of various kinds. Only proven inert materials are used in Ferrocrete, since organic materials can inevitably decay even with a lack of oxygen or atmosphere. The base mixture almost always needs to be adjusted to conform to the established grades since every planet/planetoid has a different composition of mineral matrices and soil aggregates.

It can be pumped, poured, shaped, cast, 3D printed or formed with any of the methods used on standard concrete, but with much tighter water usage controls. It can also include different fillers, dyes, strength modifiers, structural meshes, catalysts/initiators to accelerate or inhibitors to retard the cure times, or to give it ultraviolet, x-ray, gamma-ray, radioactive, chemical, caustic, electrostatic, extreme weather, exotic-atmosphere, anti-abrasion or heat -resistant properties, based on its intended application. I.E., The highest Grades (6-7) for heat and abrasion resistance (specializations) would be used in spaceports on the primary landing pads for DropShips, including their underlying flame trenches, flame deflectors and any surface-mounted blast deflectors to maximize its durability and operational life. Note, that there is no light-duty version of Ferrocrete, as that would simply be standard concrete which is very common. An example of standard Ferrocrete would be a low-cost mixture for simple structures and standard roads for heavy vehicles, or structures that must endure for hundreds of years with little to no maintenance. Heavier, more complex and denser compositions are used for extreme-use cases like mega-structure foundations, spaceports, military facilities, chemical storage sites, hydroelectric dams and reactor shielding to name a few, where durability goals exceed 1000+ years. Heavy Ferrocrete is a necessity for roads where BattleMech traffic is standard or possible, or for commercial roads that lead into or away from spaceports or rail yards.

It is not uncommon in architectural applications to set the Ferrocrete with specific materials in its internal layers, edges, corners, surfaces or even surface patterns to be even more application-specific or to provide an intended aesthetic.