Scrap tires could be used for building slope retaining walls in Brazil

The use of tires to build retaining walls in poor communities in Brazil has been endorsed by experts as an environmentally-efficient and less costly alternative to more traditional methods. A study carried years ago by the Geotechnical Institute (Geo-Rio), a local government agency in Rio, in collaboration with the Rio Catholic University (PUC-RJ) and in cooperation with the University of Ottawa, Canada, has pointed out the benefits and confirmed the effectiveness of this method.

The experiment with tire walls conducted by Geo-Rio has shown good results. A groundbreaking project was carried out in Rio's Jacarepaguá district, using 15,000 scrap tires to build a 60-meter long, four-meter high wall. Another two walls were erected in two slum communities in the city. Geo-Rio has even published a handbook with guidelines for neighborhood associations to volunteer building tire walls.

The leader of the study, PUC-RJ Professor Alberto Sayão, pointed out the tire walls are much cheaper to build than traditional masonry walls. “It's simple, fast, and cheap, and the environmental impact is minimal” he said.

According to the professor, several countries have successfully used tires for building walls, including France and Canada. In Brazil, the technique has been used in the states of Paraná and Mato Grosso, and there are ongoing experiments in Minas Gerais and Santa Catarina. “When you build the wall without adhering to certain technical guidelines, the walls can break. When that happens, people often blame it on the technique, when it's actually poor execution that caused the problem,” Sayão said.

The walls are built by tying the tires together with ropes or wires coated with plastic to make them sturdier. No skilled labor is required, it can be done manually with locally sourced labor. “If properly built, the wall is very safe and can provide social benefits as well,” the teacher explained.

Geo-Rio Project Director Luiz Otavio Vieira agrees that the method is safe, and notes that “tires can be available for free.” According to Reciclanip, an organization linked to the National Association of the Tire Industry, more then 114 tons of scrap tires were collected in Brazil—and reused in an environmentally-friendly way—in the first quarter of 2015.

According to Vieira, although tire walls are much cheaper, some residents are still reluctant to use them in their neighborhoods because of their appearance. This can be solved by using vegetation to hide the tires.

The idea is to replicate the use of this technique across the country. “Tires can be used for all retaining wall applications,” the Geo-Rio director concluded.

Translated by Mayra Borges