Is an ancient type of construction material made with concrete cast in a reusable mold or "form" and cured in a controlled environment, then transported to the construction site and lifted into place. In contrast, standard concrete is poured-in-place in large forms and cured on site. Precast "stone" is distinguished from precast concrete by using a fine aggregate in the mixture so the final product approaches the appearance of naturally occurring rock or stone.
Ancient Roman builders made use of concrete and soon poured the material into molds to build their complex network of aqueducts, culverts and tunnels. Modern uses for precast technology include a variety of architectural applications including free-standing walls used for landscaping, soundproofing and security walls. Precast architectural panels are also used to clad all or part of a building facade. Stormwater drainage, water and sewage pipes and tunnels make use of precast concrete units. The advantages of using precast concrete is the increased quality of the material, when formed in controlled conditions, and the reduced cost of constructing large forms used with poured-in-place concrete.
There are many different types of precast concrete forming systems for architectural applications, differing in size, function and cost.