By Anthony Watts – Re-Blogged From http://www.WattsUpWithThat.com
Recent winter-weather related airport delays have become something that airport managers and airline executive want to solve. This story from NBC’s today show back in January 2018 highlights the issue and a potential solution:
Could heated airport runways melt away your winter travel headaches?
There have been thousands of flight delays and cancellations due to winter weather this year, and it’s only January. Not only that: snow and ice at airports can send planes skidding off slippery runways.
What if there were something that could fix all that? At Des Moines International Airport in Iowa, TODAY national investigative correspondent Jeff Rossen got a look at a new technology in action: heated runways and tarmacs.
“We have stainless steel electrodes embedded within the concrete,” explained Halil Ceylan, head researcher of the Iowa State University team that developed the technology. “Then we connect it to power, turn the electricity on. It generates heat and it melts ice and snow on it.”
When Rossen tossed snow onto a slab of prototype heated runway, it melted into water in seconds. A thermal gun showed the heated pavement to have a temperature of 62 degrees Fahrenheit, in contrast to 22 degrees for unheated pavement nearby.
Full story here
Here is the research:
Self-Heating Electrically Conductive Concrete Demonstration Project
About the research
Highway agency staff are always in search of innovative, implementable, and cost-effective solutions to address their winter pavement maintenance issues and challenges. Considering the economic implications of even partially shut-down bridges, roadways, and highways due to ice/snow, combined with the negative impacts of applying deicing salts to pavement surfaces during snow and ice events, there is a critical need for an alternative ice and snow removal technology that is dependable, fast, and cost-effective, and has minimal impact on the environment.
Recent research studies have tried to address this need through the development of mechanical material modification and thermal- and electrical-based technologies. Among these, the development of so-called self-heating concrete surfaces, by enabling the concrete to be electrically conductive, has gained attention with potential applications for driveways, sidewalks, pedestrian crossings, city and county roads, state highways, and airport pavements.
Through a Federal Aviation Administration (FAA)/PEGASAS-sponsored research grant, the Institute for Transportation’s Program for Sustainable Pavement Engineering and Research (PROSPER) team at Iowa State University has demonstrated the potential for developing and implementing cost-effective, best-performance electrically conductive concrete (ECON) by adding conductive materials to normal concrete. Their ECON research is at a stage where it can be further expanded and demonstrated on a full-scale basis through a field demonstration project.
The Iowa Department of Transportation (DOT) maintains thousands of linear miles of roadway and several properties across Iowa including roadways, roadway shoulders, maintenance shops, and rest stop areas. The versatility of the ECON technology is such that it can be custom-designed and optimized for each specific transportation infrastructure application, including sidewalks, driveways, bridges, city and county roads, and state DOT maintained rest areas, visitor centers, and state and interstate highways, depending on the need and interest.
This versatility stems from the fact that the ECON technology is typically implemented as a conductive concrete overlay on top of the existing structure. The ECON design requirements and considerations are obviously somewhat different for each specific application warranting detailed research investigation before implementation in each situation.
For instance, implementing ECON technology in bridges requires that the design take into account the potential for corrosion of steel reinforcement, availability of a low-cost energy source (ideally geothermal energy) to power the ECON system, finding the optimal location for placing the electrodes, etc. On the other hand, ECON implementation in sidewalks has slightly different requirements, as reinforcement is rarely used in sidewalks.
In going forward with this full-scale demonstration of ECON technology for Iowa transportation infrastructure, the research team will work with the project technical advisory committee (TAC) in identifying a suitable location (ideally an upcoming construction project by the city, county, or the Iowa DOT) for field demonstration. One such site of interest to the Iowa DOT is near I-80 Eastbound in Council Bluffs, on the shoulders. There has also been interest in implementing this technology in rest areas and Iowa bridge systems.
The primary objective of this research is to do a full-scale field demonstration of the ECON technology and its efficient deicing benefits for Iowa city and county roadways and state highways. Expected benefits from this research include the following:
- A cost-effective methodology for producing electrically conductive concrete for Iowa pavement snow and ice removal application
- An understanding of electrically conductive concrete at different scales (cement paste, mortar, and concrete) and their properties
- Detailed insights into the challenges and issues faced during the full-scale construction of electrically conductive concrete
Related publication: Iowa State engineers test heated pavement technology at Des Moines International Airport Mar 2017
Sounds great right?
For air travel it most certainly is, for climate science, not so much. Here’s why this project may have unintended and potentially climatic consequences.
A good portion of the world’s surface air temperature is measured at airports, because in those cases, weather conditions are of primary importance. Because so much importance is placed on accurate and up to date weather information, the weather stations are placed near the runways, because pilots want the conditions at the the runway, not something that doesn’t reflect the landing and takeoff conditions.
A good portion of the GHCN (Global Historical Climatology Network) is made up of airport ASOS and AWOS stations, which were co-opted for climate monitoring use. This was NEVER their original mission, and these station are setup right next to runways, because they were designed for reporting aviation weather right at the runway, but not for climate monitoring.
So it stands to reason, that if heated runways become a common thing, we’ll find that the “climate signal” from these stations will likely be biased upwards in the wintertime, due to all that waste heat from the heated runways nearby. And THAT will influence the global climate data in GHCN if the upwardly biased data is allowed to stand.
(Added) And, if Des Moines becomes the first test airport for large-scale heated runways and tarmac, look where they’ll be measuring the temperature there – right in the middle of a sea of concrete:
It will certainly be an excellent example of the law of unintended consequences if airport runways become heated worldwide.