Project Description

This project focuses on the use of natural brine as an anti- and de-icing agent for winter highway maintenance. Specifically, the New York State (NYS) Department of Transportation (DOT), Onondaga County DOT and Village of Fayetteville, N.Y., will procure and utilize brine to evaluate the use of brine as an anti- and de-icing agent. In recent years natural brine has been tested by various transportation agencies in the USA and other countries. Results indicate that salt brine may have great potential as an anti-icing and de-icing agent in comparison to other conventional chemicals. Liquid salt brine applications are much more effective than solid applications in preventing ice from forming a bond with the road surface. Currently there are advanced machines that spread a salt-brine that adheres to the pavement. Unlike conventional salt-spreaders that spread salt in the form of small granules, the salt-brine is a liquid mixture of salt and water and the brine solution usually varies from 23-30 percent.

The most common chemical is salt (sodium chloride) which usually comes from mined rock salt that has been crushed, screened, and treated with an anti-caking agent. Another commonly used chemical, calcium chloride, comes from natural brines. It comes dry in pellets or flakes, or in solutions of various concentrations. Calcium magnesium acetate (CMA) is being produced and has few of the negative environmental impacts associated with salt and calcium chloride. Additives to reduce chemicals' corrosive properties are also being used. Currently these alternative materials are more expensive. De-icing chemicals work by lowering the freezing point of water. Before a dry de-icing chemical can act it must dissolve into a brine solution. The necessary moisture can come from snow on the road surface or from water vapor in the air (humidity).

Because of the negative environmental impacts of conventional salts there is a growing interest in reducing the volumes of conventional salts used in highway maintenance. Negative environmental impacts include salt being carried into public waterways, impact on plants and aquatic organisms. Pre-wetting with salt brine is an alternative that has been studied for quite a while. Results are very positive for the use of salt brine as a pre-wetting agent. Pre-wetting results are sometimes a function of the road site specifics such as volume of traffic, weather conditions etc.

This project focuses on detailed investigation of the feasibility of salt brine applications for winter highway maintenance globally and within the USA. It also focuses on a pilot study to be conducted at select sites in Syracuse, New York to collect real data to determine the impact of salt brine application.

The overall technical research objectives of this research are to:

• Conduct a thorough literature review of current practices employed by all states in the USA and select countries for use of natural brine in highway maintenance;
• Prepare a report summarizing the findings of the literature review;
• Investigate use of natural brine application via a pilot study;
• Prepare a brine application database
• Evaluate brine application rates, impacts, costs etc. and compare it to roadways using other conventional methods;
• Prepare deliverables such as handbooks, reports, presentations etc. to aid the transportation industry.