- Bridge Building
- Bridge Designers
- Eugene Freyssinet
Eugene Freyssinet
Eugene Freyssinet was born in France in 1879. He graduated from the Ecole des Ponts et Chausses in Paris. In 1907, in the early years of his career, he was given the opportunity to rebuild three suspension bridges over the River Alliers with his own design. He offered, and it was accepted, to build three reinforced concrete bridges for the estimated price of one of the suspension bridges. Each of the spans were in excess of 70m (230 ft) and, in carrying out load tests, he discovered the concept of concrete “creep” i.e. further consolidation of concrete after it has hardened.
Freyssinet then proceeded to design and build barrel vaulted buildings such as the hangers at Orly Airport. Then in 1930 he constructed the Plougastel Bridge in Brittany. This three span (180m/590 ft each) reinforced concrete arch bridge surpassed all records at the time. In addition it was designed to carry traffic on two levels, namely trains on the upper level and road traffic on the lower level. In compensating for the creep effect this bridge highlighted for Freyssinet the potential in prestressing concrete.
The principle of prestressing had been invented by others but Freyssinet developed it further, particularly post World War II when materials, especially steel, was scarce. Both prestressing and post tensioning allowed longer spans and shallow bridge decks to be constructed. This type of bridge material presented an alternative choice to steel, particularly where local materials were readily available. Freyssinet was very much involved in improving the quality and strength of concrete and the use of high strength wire for stressing.
After Robert Mallart, Freyssinet is the second great name in the early 20th century for concrete building. While Maillart’s bridges were generally designed for the lighter traffic experienced in the Alps, Freyssinet developed concrete to cater for today’s commercial road and rail traffic.
He died in 1962.