Bridges presentation
lift the arches off the falsework and filling the gap with concrete, leaving only permanent
compressive stresses in the arches. The Vauvray Bridge over the Seine was the record span at 430ft
(131m), the deck being hung from hollow cellular arch ribs on wire hangers, coated with cement
mortar, and supporting the road on light concrete deck trusses. The Vauvray Bridge was destroyed in
World War II, leaving the Plougastel Bridge (1930) over the River Elon at Brest, with three spans of
567ft (173m), as the longest reinforced concrete arch span until 1942.
Swiss engineer Robert Maillart designed three-hinged arches in which the deck and the arch ribs
were combined to produce closely integrated structures that evolved into stiffened arches of very
thin reinforced concrete and concrete slabs, as at the Schwandbach Bridge (1933), near
Schwarzenbach (Switzerland). Maillart's early apprenticeship with Hennebique sharpened his
awareness of the plastic character of the material
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