Concrete

Concrete is a material made combining sand, cement, water and little stone pieces. It hardens rapidly and resists water and fire. It's strength is very good for compression but not so good for tension. Therefore in the 1860s was invented the reinforced concrete which adds steel or other metals to the configuration of concrete, providing good tensile strength. Concrete is suitable for many type of structures. Its advantage over other materials is that it can be poured in liquid state into any form and it does not require joints. Precast-concrete and pre-stressed concrete are later inventions. The first one includes bricks, slabs and supports, reducing expansion and contraction. The second one allows the structure to resist heavier loads than other concretes does.

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