Winter is upon us, and in many parts of the United States, this means significant amounts of snow and ice. Winter weather conditions can wreak havoc on roadways — especially when they can’t be plowed in a timely manner. But, what if that could change? With phase change materials, roads may soon be able to clear themselves.
What are phase change materials?
Phase change materials are substances that generate and radiate heat when exposed to cold temperatures. Heat is generated through the physical change from a solid to a liquid.
How are they used with concrete?
Recent tests at Drexel, Purdue and Oregon State Universities demonstrated that when phase change materials were incorporated into concrete, the final product was able to generate its own heat.
Currently, paraffin oil is being tested as a phase change material. Paraffin oil is used due to its stable nature, rate of thermal release, availability, low cost and environmental impact. The oil is introduced into the concrete as an additive to a porous aggregate, or placed in tubes within the concrete structure. Each method creates a unique thermal release that promotes the melting of snow and ice.
What’s the impact?
In a controlled environment, phase change incorporated concrete demonstrated the ability to melt five inches of snow at freezing temperatures, over a 25-hour period.
These findings are important to cities, states and airports in colder regions. The concrete’s ability to melt snow and ice can improve the safety, environmental conditions and financial impacts associated with road, bridge and runway snow removal.
Governmental agencies spend significant amounts of money to scrape, de-ice and salt surfaces to keep them safe for public use. With the use of phase change materials, the need for de-icing and salting can be significantly reduced — if not eliminated. The current environmental impact from salt and chemical de-icing runoff can also be reduced. Moreover, reduced plowing can also significantly reduce vehicle maintenance, road surface deterioration and man hours.
While additional research is needed to determine the viability of commercial use, the recent testing demonstrates the technology holds great promise for airports, bridge surfaces, roadways and other applications.
