Category Archives: Engineering

Why reinforced concrete matters so much

Reinforced Concrete played an important part in building America and It’s Industry

Concrete and steel in useful, economic quantities were first developed in the 1800s.

Joseph Monier obtained his second patent related to reinforced concrete in 1877. He used it in the making of flowerpots. Specifically, before concrete is poured into a form, rebar is added inside the form where the resulting structure would experience tensile forces. The rebar is a twisted spiral rod so that the concrete can “grip” it better after it sets. (Other types of reinforced concrete that use other tension resistant materials are being developed, but steel is still the most typical companion material.)

Steel and concrete have similar coefficients of thermal expansion so internal stresses remain low as the temperature of the reinforced concrete changes. The concrete must be mixed correctly to make sure the steel does not rust. Rust expands, and it will crack the concrete.

When the Delaware,viaduct Lackawanna & Western Railroad built a 28.5-mile cutoff between 1908 and 1911, it used reinforced concrete for all of its structures.

The Paulinskill Viaduct was 115 ft tall and, at the time it was built, the world’s largest reinforced concrete structure.