Cement mixed with water is virtually a plastic stone, and it can be used for many purposes in place of stone with economy in shaping to the form required, and advantage in securing a hard, fire-proof material. It may be used for shop floors, buildings, foundations for heavy machinery, bridge piers, walks, waterworks dams, reservoirs, walls, dry-docks, culverts, etc. A concrete casing will protect iron or timber structures from corrosion in air or in water, and will protect exposed iron work of structures from effects of conflagration.

Strengthened with iron bars, or meshed wire, placed in it when it is being moulded to shape, it is known as re-enforced concrete, and will thus form bridge floors, bridge spans, and the upper floors of buildings which must support great weight.

In marine use, concrete is limited because of its weight. It may be used as permanent ballast in the bilges of steel ships, and is an effective protection from corrosion when applied to absolutely clean iron or to iron surfaces covered with closely adhering red rust. When so used, cement may be mixed with water and applied with a brush, or it may be mixed in the proportion of about two parts sand and one part cement and applied wet, with a trowel, in a layer varying from 1/4 inch to any thickness desired. In this way ships' tanks, bunkers, and bilges are protected, as the mixture forms a close bond with the iron. In no case will this bond form if the iron is oil coated.