Performance Rating of De-Icing Chemicals for Winter Operations Chris Tuan, Ph.D., P.E. Barbara Gerbino-Bevins, Civil Engineer Mike Mattison, P.E.
Jan 14, 2015
Performance Rating of De-Icing Chemicals for Winter Operations
Chris Tuan, Ph.D., P.E. Barbara Gerbino-Bevins, Civil Engineer
Mike Mattison, P.E.
Objectives
• Research and develop standardized tests to analyze the performance of chemical deicers
• Correlate laboratory data with field data• Research and develop best practices regarding the
use of chemical deicers
Overview
• Literature Survey• Shaker Test
– Procedure – Results
• Field Data Collection– Road Condition Rating System– MDSS and AVL Data
• Best Practices
Literature Survey
• Chemical Deicers– NaCl, MgCl2, CaCl2 , Potassium Acetate, “Beet
Juice”– Liquids and Solids
• Practices– De-icing: Reactive– Anti-icing: Proactive– Prewet Solids
Literature Survey
• SHRP Handbook of Test Methods for Evaluating Chemical Deicers– SHRP Ice Melting Capacity Test: Does not
correlate well with field data– Resulting roadway friction after treatment – Ice penetration and Ice debonding– Thermal Properties
• Research Sponsored by Clear Roads and Northwest Pacific Snowfighters
Shaker Test
Martini ShakerThermocouple
1-mL Ice Cube TrayFreezer
Shaker Test Results
Shaker Test: Liquid Results
Shaker Test: Liquid Results
Shaker Test: Liquid Results
Shaker Test: Beet Juice Results
Shaker Test: Solid Results
K Ace Reaction
Shaker Test: Conclusions
• Test Results– Low Variance for Each Temperature Group– K Ace Reacts with Road Salt– How Beet Juice Works
• The Shaker Test– Quick, Simple, Inexpensive– Repeatable– Produces Consistent Results for Liquids and
Solids at 20°F, 10°F, and 0°F
Field Data Collection
• Maintenance Decision Support System (MDSS) – Web-based software– Records Vehicle Location– Weather Data
• Automatic Vehicle Location (AVL)– Time Stamps of Plow Truck Locations– Records Data about Chemical Application– Takes Pictures from the Cab
Field Data Collection
• Maintenance Decision Support System (MDSS)– Weather Data
Field Data Collection
• Maintenance Decision Support System (MDSS)– Records and time stamps vehicle location
Road Condition Rating System • Based on what can be seen from the truck
– Lines and wheel tracks• 100% Covered
– Cannot see roadway
• 75% Covered– Can see some roadway– Cannot see two defined, continuous wheel tracks or any
lines.
Road Condition Rating System• 50% Covered
– Can see two defined, continuous wheel tracks– Cannot see lines
• 25% Covered– Can see two or more wheel tracks– Can see one or more lines
• 0% Covered– Can see inner and outer lines– Little or no snow is on roadway
Beet Juice Treatment with and without Sunlight
Road Salt Treatment under High Winds
Best PracticesLiquids
• Best used at temperatures greater than 20°F• Pencil nozzles work well for post-treatment of ice or
compacted snow layers greater than ¼ inch. • Best choice for anti-icing• Can be used during events with precipitation rates less than
0.5 in/hr• Retreat every 1½ to 2 hours to prevent refreeze
Solids• Can use at temperatures as low as 12°F• Works well for post-treatment of ice and compacted snow• Smaller gradations tend to work faster, but also refreeze
quicker • Coarse grained deicers can be used during events with
precipitation rates greater than 0.5 in/hr
Best Practices
• Not recommended to use deicers or abrasives if wind speed is greater than 15 mph
• Abrasives with a pre-wet are much more effective than dry abrasives
• MgCl2 and CaCl2 work better than NaCl at temperatures lower than 20°F, but can cause slippery roads if humidity is higher than 40%.
• Beet juice works well in direct sunlight
Conclusions
• Shaker Test can be used to screen new deicers or compare the performance of different deicers
• Field Data Collection– Processing MDSS and AVL Data is Time
Consuming– Provides Useful Snow Events Information for
Correlation Study– More Data Required for Statistical Significance
Acknowledgments • NDOR Technical Advisory Committee:
– Jasmine Dondlinger, Jodi Gibson, Lieska Halsey, Wally Heyen, Dalyce Ronnau, Amy Starr, and Gary Story.
• District Maintenance Managers:– Ray Branstiter, Dale Butler, Kelly Doyle, Chris
Ford, Allen Horak, Roger Klasna, and Roger Kalkwarf.
• City of Omaha Public Works:– Scott McIntyre.
Slide design © 2009, Mid-America Transportation Center. All rights reserved.
Barb Gerbino-Bevins, NDORMike Mattison, NDOR
Chris Tuan, Ph.D., UNL
CREDITS