Israel’s formula for getting green mileage from old tires could be a boon for countries with similar raw materials and climates.
Old, used tires are an environmental nuisance. But now a new “green” project in Israel intends to recycle the rubber from old tires, and use as many as 1,400 tires per kilometer of new paved highway.
In a pilot trial, a 1.1 kilometer section of road was paved using an experimental mixture that included hundreds of recycled tires and a blend of asphalt.
At no greater cost than paving a regular road, this new product can increase the life of the pavement by one-third without, the developers believe, compromising safety. Developers anticipate that their technology can be applied in countries in the Middle East and elsewhere with similar climates and conditions as Israel.
About three million tires go out of service in Israel every year, and they are often found discarded and scattered at various locations.
“We are talking about 15 percent of the total wasted tires in Israel. Something like 700 tires in one kilometer of lane; in one experiment, we doubled this figure up to 1,400 tires,” says Israel National Roads Company R&D branch director Adrian Valentin Cotrus.
While the idea to reuse shredded rubber on roads came through a technology transfer meeting between Israel and America back in 2005, the results from the pilot trial on a highway section of Road 85 in the Galilee, up north, will benefit its Israeli developers: the Israel National Roads Company, the Ministry of Transport, the Ministry of Environmental Protection and the Technion-Israel Institute of Technology.
Expect the compound and equipment needed to produce the recycled tire asphalt to be ready for sale by the end of this year, Cotrus says.
Like baking a cake
Recycled tires are now being incorporated into roads in Arizona and Texas. “We found we have the same problems as the US when tires go out of service. Soon it will be forbidden to bury them in landfills,” Cotrus tells ISRAEL21c.
However, when the company tried a US blend, it disintegrated on the Israeli roads, which can be scorched with temperatures hot enough to fry an egg in the summer, without the benefit of rain to cool them down.
Israel’s climate and raw materials are different than those in the United States. So although making asphalt from recycled materials is just like baking a cake, says Cotrus, “we are not working with the same flour, oven and local temperatures.
“Our local rubber is the same, but in order to implement the technology, we have to consider the surface bitumen, the different climate and what’s being provided by the local asphalt factories.”
So it was back to the drawing board. “Since our company is seeking the use of recycled materials in many other fields, we thought recycling the rubber tires into asphalt would be a real possibility, but we needed to do extra R&D here.”
Theoretically, this Israeli technology could be transferred to other countries that share similar raw materials and climate. For now, the Israel National Roads Company will put out a tender seeking a commercial producer for the recycled blend.
Energy from the streets
The idea for recycling tires into paving material started with Alan Bilinsky from the US Embassy in Israel. He put the Israelis in touch with Americans who are already recycling tires for roads.
Israel’s tech transfer relationship with the United States doesn’t only go one way. In the last couple of years, the Israel National Roads Company, in collaboration with Innowattech, has been developing a novel way to collect the mechanical energy created when cars and trucks pass over roads and highways. This is something Americans are very interested in exploring.
Using piezoelectric crystals that generate electricity when depressed, so far the result of the pilot in Israel “exceeds the expectations of professionals,” says Cotrus.
Based on the same system, the companies are developing a sensor technology called “Weight in Motion,” designed to collect data about the weight of service vehicles and cargo trucks. This is of interest to many countries, including Israel and the United States, where overweight trucks can damage roads and bridges and can lead to severe traffic accidents.