Plastic forms

Molded fiberglass-reinforced plastic formwork “is now more than just an intriguing possibility,” said a September 1960 article. Suddenly it became easier to make unconventional shapes, using these forms that promised light weight, corrosion resistance, smooth surfaces, easy release, reuse, quick assembly and dismantling, and no need for cleaning or form oil.

Engineered wood forms

In answer to the lumber shortages and rising prices of the 1990s, forming systems made of structural composite lumber (SCL) offered “the consistency of aluminum and the workability of wood,” according to an October 1998 article.

Residential aluminum forms

An August 1990 article touted a new aluminum panel forming system that would allow casting a complete house—walls, partitions, and roof—in a single continuous pour. The proprietary package included all components needed to form the home, drawings, and training of a site superintendent.

Flying forms

In a 12-story apartment building project described in May 1965, the floors were placed using a “novel” system of “flying forms”—horizontal forming units supported by adjustable scaffold legs.

Insulating forms

A market-transforming development arose in the mid 1970s. Prefabricated rigid urethane insulating forms, molded into boxlike units with finished sheet materials attached, appeared in the January 1974 issue. The technology quickly evolved away from the combustible urethane, and by November 1977, “fourth and fifth generation versions” used fiberglass, mineral wool, treated cellulose, and inorganic noncombustible materials. A March 1992 article described hollow-core expanded polystyrene (EPS) forms that snapped together “like gigantic foam Legos.” According to a January 1995 report, stay-in-place wall forms had revolutionized home construction in about a decade of use.

Shrink forms

The November 1986 issue introduced a hydraulically powered machine featuring a shrinking core for forming voids. Once the concrete placed around the core hardened, the self-stripping machine would contract away from the concrete and then expand to its original shape for the next pour.