Reducing Icy Conditions Over Bridges, Through Passive Means

  • Dr. Hussein Abaza
  • Dr. Charner Rodgers

Abstract

Icy road conditions are a major cause for car crashes.
70% of all roads in the United States are located in icy regions,
and winter and snow related maintenance account for 20% of the
roads maintenance budgets (FHWA, 2017), Snow also reduces
the average road speed by 30 to 40% on roads. More than 450
people are killed each year in the United States due to icy
conditions on roads (icyroadsaftey.co, 2015) of which more than
10% of these deaths are caused by accidents over icy bridges.
Due to this, many innovative systems have been designed and
used to prevent bridge icing. Most of these systems either use
heat sources to heat the bridges’ surfaces or chemical spray to
melt the ice that forms over bridges. Unfortunately, these systems
are usually costly and require regular maintenance. Many
researchers contributed bridge icing to the fact that bridges are
suspended above ground resulting in bridge surfaces to freeze
before adjacent roads, thus bridge decks lose heat from both the
top and bottom surfaces while roads gain some heat from their
contact with the ground. However, field monitoring and building
simulation showed that the thermal properties of bridge surfaces
are the true determining factor as to why bridges freeze before
adjacent roads. Furthermore, icy bridge surfaces become
dangerous when 1) the bridge’s surface reaches freezing point
before adjacent roads, and 2) the existence of water or snow over
bridges when adjacent roads are dry (preferential icing). This
research presents literature review related to bridge freezing.
The research also used field observation of a 175-mile highway
section during a snowstorm to investigate icing conditions over
bridges. This research revealed that while bridges might freeze
before roads during early night hours, dangerous icing formation
over bridges occurs when snow is shoveled against the bridges’
parapets after snowstorms. Thus, when air temperature rises
above freezing, the snow melts and the water runs over the
bridges’ surfaces. When temperature drops again below freezing
later at night, water can freeze over bridges and create
dangerous icy conditions. This research suggests that a
combination of applying paint with higher absorptive and lower
emissive materials over bridges, along with better snow removal
practices, will reduce the dangerous icy conditions over bridges
significantly.

Published
2018-06-18
How to Cite
ABAZA, Dr. Hussein; RODGERS, Dr. Charner. Reducing Icy Conditions Over Bridges, Through Passive Means. GSTF Journal of Engineering Technology (JET), [S.l.], v. 5, n. 1, june 2018. ISSN 2251-371X. Available at: <http://dl6.globalstf.org/index.php/jet/article/view/1731>. Date accessed: 19 nov. 2018.