April 22, 2014
Turning Old Tires Into A Useful Material To Improve Roadways
Gerard LeBlond for www.redorbit.com - Your Universe Online
According to the EPA, there are approximately 300 million discarded tires every year in America. Frequently these tires are thrown into landfills or discarded illegally and are a potential fire hazard.
However, in recent years these no-longer-useful tires have been the topic of new and innovative ways of being used. Magdy Abdelrahman, an associate professor of civil and environmental engineering at North Dakota State University, is creating a way to use old tires to improve the roads we travel every day.
He is experimenting with “crumb” rubber -- which are old tires ground up into different sized particles -- and combining them with other materials to improve roads. The experiment is funded by the National Science Foundation (NSF).
“It's very durable. We mix it with different materials and in different percentages, and in different conditions, to find the best ways to add rubber to asphalt,” Abdelrahman said.
The EPA says that 220 million pounds, or 12 million tires are used to make asphalt rubber. Many states already use asphalt rubber in their road construction, with California and Arizona using the most. Florida, Texas, South Carolina, New York and New Mexico also use rubberized asphalt or are experimenting with it.
Adding rubber to asphalt results in road surfaces lasting longer, reducing noise and creating less road maintenance.
“This project will have a broad impact because solid waste is problematic throughout the world. Asphalt applications have the potential to contribute to the solution of the growing solid waste problem provided that engineering and environmental concerns are addressed. Asphalt binders represent an area that can improve pavement performance,” Abdelrahman added.
He is also researching the environmental effects, if any, by the additives being used and the interactions during bad weather and its impact on soil and ground water.
“We want to assess the environmental impact of adding components to the mixing of crumb rubber and asphalt, for example, is it going to leach out in the rain? Traditional, that is, normal, asphalt-rubber materials will not cause harm to the soil or the ground water. But some additives may. We already know that the technology [rubberized roads] is proven to work, but we want to make it work much, much better. We are trying to find the scientific and engineering aspects to make it better and, at the same time, be sure it is environmentally friendly,” he added.
An NSF five-year grant of around $400,000 will also provide educational courses linked to Abdelrahman's research in the area of recycled materials. Plans to develop procedures to train and mentor students in undergraduate and graduate programs in the field are also in the works.
“We want to get the undergraduates involved in research activities and show them the technology we have developed,” he says.
"[The outreach program] will raise the awareness of K-12 students to the environmental issues facing the local as well as the global community regarding solid waste management. We will hold classes, seminars, even with kids in elementary school and show them: let's recycle some material,” he said.
“It is really important for them to understand that if we keep using new materials, that our grandchildren won't have anything left. We're trying to get them to think about what will be available to the next generation in the way of resources if we cannot, or do not, use recycled materials. The goal is to educate high school, middle school and elementary school children, and show them that this is what needs to be done,” he added.