New Age Materials
Process of obtaining:It is the direct result of smelting iron ore (pig iron) in a blast furnace with coke. The molten iron and the slag - residual waste pour out on either side from the base of the blast furnace. The liquid ore solidifies on cooling.
Year of invention : The process was first carried out circa 1710.
Characteristics & uses:
• Can be given the desired shape by being poured into moulds.
• Cast iron is brittle and reacts to bending stress.
• Used primarily for vertical columns.
The cast iron columns were used in
- Victoria Station, London (1861) and
- Woodside Station, Birkenhead (circa1876)
The Crystal Palace, Hyde Park, London, 1851 by Joseph Paxton (1803-1865). Width of Crystal Palace is 408’. It was constructed in seventeen weeks in cast iron with pre-fabricated standardized parts and based on multiples of 24’ standard glass size 49” by 10”.
By 1858 , in the United States of America, the advantages of cast iron were realized and New York witnessed many cast iron buildings, as in the Project, New York World’s Fair (1853) by James Bogardus (1800 -1874)
Victor Horta (1861-1947) made distinct design statements with cast iron, in his Art Nouveau buildings at Brussles.
Process of obtaining: is obtained by oxidizing white-hot cast iron. It is puddle (purified) from an excess of carbon and impurities in a ‘reverberatory’ furnace.
Year of inventionCircal 1760s
Inventor Henry Cort
Characteristics: Ductile and malleable,wrought iron can be pulled out into wire or rolled into beams.
The Eiffel Tower, Paris, 1887-89 was constructed of wrought iron by Gustave Eiffel(1832-1923) Though sweepingly and in a general manner the Eiffel Tower is said to be an ‘all-steel’ structure, it is constructed with wrought iron.
The Truyere Bridge, France by Gustav Eiffel
Structures with cast iron columns and wrought iron beams to with stand both compression and tension became an exclusive constructional method in the mid nineteenth century. The steel beams were brought together through flanges. And bounded / enclosed the diagonally placed web. The beam thus consisted of a compression boom and a tension boom with the strut and tie taking care of the thrust of compression and tension, respectively. Rivets and bolts were used for joining the various parts and sections.
Process of obtaining: Steel is made from cast iron, the carbon being burnet out by a blast of air through the molten metal in a ‘Converter’.
Year of invention: 856
Inventor: Sir Henry Bessemer
Characteristics Steel has equal strength in compression and tension.
Galerie des Machines, International Exhibition, Paris, was a steel and glass structure of 1889. It was designed and erected by Dutert and Cottamain - the latter was the engineer. It was is a construction of a series of three-hinged steel arch . The steel beams to which cross beams were riveted to form a rigid framework. The Fair building, Chicago, U,S.A. (1891) by Willaim Le Baron Jenny (1832 – 1907) was one of the earliest steel frame building.
The Chicago School (1883) and the birth of the sky scraper are the success stories of structural steel
However the ‘skin and bone’ architecture that resulted effected the steel frame construction and the birth of skyscrapers was made possible by combining structural steel and reinforced concrete
The skyscraper legacy was, taken forward by the international Style that emerged in the 1930s / 1950s, focussing more on glass facades and innovative looks than merely the steel structures. This was embodied in the 100 storeyed John Hancock Centre in 1969, the city of Chicago’s favourite skyscraper till date. The 1.127 feet high building is dominated by huge X-braces that give structural stability and also move the eye away from the windows in human-scale and glass curtain walls. The braces are actually square steel tubes and carry most of the weight of the building, with the result that no interior supporting columns are necessary and even the floor space is maximized. The innovative construction required almost half the amount of steel a ‘conventional’ skyscraper with interior columns would have. This new construction method was made possible by new technologies like advanced software and innovations in steel.