Concrete bridge

Kuradisild from 1913 in Toome Hill, Tartu, Estonia

Concrete bridges are a type of bridge, constructed out of concrete. They started to appear widely in the early 20th century.

History

Pont du Jardin des plantes, Grenoble, poured concrete foorbridge, constructed 1855.

Homersfield Bridge, England, cast iron reinforced, constructed 1869-1870

Bridge across the moat at Château de Chazelet, constructed 1875.

Axmouth bridge, constructed 1877.

Unreinforced concrete has been used in bridge construction since antiquity: the Romans incorporated concrete cores into a number of their masonry bridges. From the late 18th century cast iron framed bridges may have had a unreinforced cast concrete deck, or had their structure encased in concrete, for example the Homersfield Bridge, constructed between 1869 and 1870, between the English counties of Suffolk and Norfolk. In 1873, Frenchman Joseph Monier obtained a French patent for a method of reinforced concrete bridge construction; his first reinforced concrete bridge was constructed across the moat of the marquis de Tillièrein's fr:Château de Chazelet, in 1875. This and all later bridges made according to Monier's system patterned the construction of previously used stone bridges. Their main structural unit was an arch barrel. All barrel sections were reinforced similarly, regardless of the forces acting on it.

An example of a reinforced, cast concrete bridge is the Waterloo Bridge, built in London between 1928 and 1945. It has two spans of 50 feet each and average spans of 110 feet.

The world longest span made of regular concrete is the average span of the Rocky River Bridge in Cleveland, Ohio. It is 128 feet long. Now reinforced concrete with steel rods is mainly used and can be built much faster than stone and regular concrete arches.

Early extant examples include:

Finland

• Savisilta "clay bridge", Ylivieska, the second oldest concrete bridge in Finland. (reinforced concrete, constructed 1912, picture 1).

France

• Pont du jardin des plantes, Grenoble, foorbridge (cast concrete, constructed 1855)
• Bridge across the moat at Château de Chazelet (reinforced concrete, constructed 1875)

United Kingdom

• Axmouth Bridge, on the River Axe at Seaton, Devon (unreinforced, middle span 50 feet, opened 1877)
• Homersfield Bridge, River Waveney, England (cast and wrought iron reinforced, span 50 feet, constructed 1869-1870)
• Glenfinnan Viaduct, Scotland (unreinforced, twenty-one 50 foot spans, constructed 1897–1901)

United States

• Alvord Lake Bridge, Golden Gate Park, San Francisco (reinforced concrete, 29 foot span, 1889).