Section 2: Bridge DecksAnchor: #i1000327
Risks of Chemical Damage
Bridge decks, especially overhangs and joints, are at great risk of incurring de-icer related damage. When evaluating design loads, overhangs exhibit the greatest levels of stress in the deck design. Overhangs also store snow pushed by plows. The snow pushed by plows is typically laced with de-icers, possibly saturating our high stress areas with corrosive chemicals. Steel under stress corrodes at an accelerated rate. So, storing snow on overhangs is not an ideal situation.
The damage begins when the snow melts and concentrates the corrosive forces in the de-icing agents in the overhangs.
Sweeping bridge decks at the end of the winter weather season is necessary to reduce leaching of de-icing agents throughout the summer months.Anchor: #i1000343
Washing the Deck
To prevent as much damage as possible, wash the deck when the temperatures rise and snow season is over. Washing helps in two ways:
- Anchor: #HKHANDJI
- physically removes remaining chemicals Anchor: #UTLRVKUT
- dilutes any chemical residues, reducing their corrosion potential.
Figure 5-1. Corrosion damage due to concentrated de-icing solution at drain site.
Figure 5-2. Corrosion damage due to concentrated de-icing solution at drain site.