Bridge Deck Thermography: Revisiting ‘Bridges Freeze Before Roadway’ From a Safe Salt Perspective

Emily Bollendorf, Dr. Stephen Druschel, Department of Civil Engineering, Minnesota State University, Mankato, 228 Wiecking Center, Mankato, MN 56001

“Bridge Ices Before Road” is a road sign almost every driver has seen, however, the magnitude of that statement is not always known. Icy bridges pose a safety concern for drivers in winter weather conditions.  Bridge decks freeze before surrounding roadways due to their exposure to wind and cold temperatures from all directions.  Wind cools the bridge deck from the top, bottom and sides.  Bridges also do not have insulation and warmth radiating from the ground that roadways do.  These factors lead to the rapid formation of ice on bridge decks, which can cause drivers to lose control of the vehicle and crash.  Plow drivers attempt to mitigate the problem by applying salt and other deicing mixtures, however, salt has a devastating impact on the ecosystems when it runs off into nearby bodies of water.  Deicing performance is also sensitive because a fifteen-degree differential can cause up to an eight-fold difference in snow and ice melt.  This greatly impacts deicing decisions, considering temperature differentials can occur within fifty feet of bridge deck length.  Understanding how various construction and location factors impact the thermal response of bridges would help engineers design and maintain safer roadways for drivers.    

This research project analyzes the thermal response of various bridge types in winter weather conditions.  Using a Forward-Looking Infrared Camera (FLIR) and laboratory experiments it was concluded that bridge material, orientation, size, and landscape underneath the bridge impact the rate at which bridge decks freeze.

Additional Abstract Information

Presenter: Emily Bollendorf

Institution: Minnesota State University, Mankato

Type: Poster

Subject: Civil Engineering

Status: Approved

Time and Location

Session: Poster 4
Date/Time: Tue 11:00am-12:00pm
Session Number: 3639