2. Main repair methods for steel bridges

2.1 Lighter structures

The decks of many older structures are either vaulted, or made of downward-bent sheet metal covered with a thick layer of lean concrete or rubble; these coverings are heavy (between 8 and 10 kN/m ² in common cases).

Replacing these covers with a slab of standard reinforced concrete (density ∼ 2,500 kg/m ³ ) or light reinforced concrete (density ∼ 1,900 kg/m ³ ) significantly reduces stresses in the structure. The close spacing of stringers and bridge members often enables the design of thin slabs (19 to 21 cm to comply with current reinforced concrete reinforcement coverings), which provides, in the case...