While most of the country is coming out of the winter months — at least according to the calendar — some regions (namely the Northeast) are still vulnerable to late season weather events.

Unfortunately, ice, sleet, freezing rain and snow are all still possible as we make our way to the light-at-the-end-of-the-tunnel that is spring. Meanwhile, a byproduct of those weather conditions includes icy roads and sidewalks.

Source: Becca8383/CC BY-SA 3.0

Icy roadways and sidewalks present significant hazards for those both walking and driving. Yet, while many chemical-based de-icing solutions exist for lowering the risk of injuries and accidents — which they reportedly do by an estimated 85% — these solutions are not always ideal for infrastructure and the surrounding environment.

According to experts, sodium chloride, magnesium chloride, calcium magnesium acetate and potassium acetate are the most commonly used de-icing solutions by the majority of U.S. municipalities. However, their use is closely associated with contaminating drinking water, endangering wildlife, increasing soil erosion, damaging roadways and eroding metal vehicles.

As such, a number of efforts have been undertaken to de-ice walkways and roadways without impacting infrastructure and the environment.

In a follow-up to our recent feature on deicing airplane wings, this article will examine the alternatives being explored for de-icing roadways.

Blankets

In a bid to melt stubborn snow that seems to hang on well after it initially falls, scientists from Virginia Tech tested the melting power of sunlight-absorbing thermal blankets and found that they are capable of melting snow three times faster than traditional snow-melting methods.

The team of researchers turned to a new type of thin, conductive and thermally absorbent metal blanket. In the lab, scientists tested three different versions of the blanket — all made with an aluminum alloy but two coated with black enamel or black silicon-based spray paint that absorbs sunlight while the third blanket was bare aluminum.

Experimenting with piles of snow and a high-intensity lamp to simulate sunlight, scientists determined that the snow covered by the aluminum blanket melted at roughly the same rate as uncovered snow while the blankets coated in black paint sped up melting by 300%.

Grapes

Researchers from Washington State University (WSU) are turning waste from grape skins into a sustainable and environmentally friendly de-icer.

Through a process of chemical degradation along with natural fermentation, the WSU team used the chemicals from grape skin waste to develop the de-icer, which reportedly outperformed other deicers, including road salt, salt brine and beet juice, melting ice and snow faster, without posing a threat to nearby ecosystems and without corroding the concrete or asphalt of roads.

Conductive concrete

A team of scientists from the University of Lincoln-Nebraska (UNL) in collaboration with the U.S. Federal Aviation Administration (FAA) has tested a concrete mix composed of steel shavings and carbon particles capable of conducting enough electricity to melt ice and snow.

The material — which is a standard concrete mixture featuring 20% steel and carbon ingredients — conducts electricity enough for melting ice and snow.

The team is eyeing the concrete for airport tarmacs.

Microcapsules

Researchers in China are taking a salty approach to de-icing roads: Microcapsules filled with a chloride-free salt mixture embedded into asphalt ahead of paving. This, according to researchers delivers long-term snow melting capabilities. A fine powder is achieved through the combination of a sodium acetate salt with blast furnace slag, silicon dioxide, sodium bicarbonate and a surfactant. Microcapsules featuring the fine powder are then created with the application of a polymer solution and the capsules are then incorporated into asphalt mixtures used to create roadways.

In the lab, pavement blocks featuring the new sustained-release additive lowered the freezing point of water to -6° F. Further, a 5 cm thick layer of the enhanced asphalt is expected to effectively melt snow for seven to eight years. Additionally, the team determined that the anti-icing asphalt added to the off-ramp of a highway during tests melted snow that fell on the road while traditional pavement treatments required additional removal operations.

Cheese

A state famous for its cheese has been putting one of its valued exports to work: as a roadway de-icer.

In recent years, Wisconsin has been turning its beloved cheese into an alternative to rock salt. Cheesemakers have been donating cheese brine, a product of cheesemaking, to select municipalities in the state. Because it reportedly freezes at a lower temperature than salt brine, it was added to rock salt. During a series of tests, the cheese brine enhanced rock salt proved to adhere better to roads than traditional de-icers while also saving municipalities money.

Molasses

In other parts of the U.S., molasses is being added to untreated rock salt. This sweet approach, according to some municipalities, suggests that molasses is less corrosive than traditional rock salt mixtures and binds well to roadways.

Beer

A New Hampshire based company has created its own road de-icing solution derived from beer. Ice Ban is a mix of hops, which is a grain used in the making of beer. By combining the hops with a liquid salt, the team arrived at an environmentally friendlier and less corrosive alternative for de-icing roadways.

According to the makers of Ice Ban, the hops enhance the performance of the rock salt, allowing salt to stick to roadways amid freezing temperatures, while regular rock salt generally fails to work under temperatures below 20° F.

Pickles

Another environmentally friendly alternative to rock salt is pickle brine. Researchers suggest that pickle brine melts ice at temperatures lower than rock salt. Added to untreated surfaces ahead of ice or snow fall, and pickle brine reportedly prevents both ice and snow from binding to the surface.

Bitumen

A team of scientists from Turkey's Koc University have found that mixing salt potassium formate with the water-repelling polymer styrene-butadiene-styrene and adding it to bitumen — an ingredient in asphalt — will delay ice formation for up to two months.

According to the researchers, incorporating hydrophilic salts into bitumen, which is a hydrophobic asphalt binder, and controlled release of specific molecules from this medium can reportedly offer an effective solution for reducing ice formation on pavements. Further, embedding the salt-polymer composite within the bitumen at the time of manufacture would enable a steady, controlled release as the pavement is worn away over the years.

Check back with GlobalSpec.com for more about our series on surface de-icing solutions. Next time we will investigate the solutions for de-icing solar panels.