By Jimena Naser
In response to this problem, Rosana Gaggino, CONICET associate researcher at the Centro Experimental de la Vivienda Económica (CEVE, CONICET-AVE), developed together with her team of collaborators, a process for the use of recycled plastics in the elaboration of constructive elements , in this case polyethylene terephthalate (PET) * bricks.
"We use PET from disposable beverage containers and portland cement as a binder, plus a chemical additive that improves the adherence of plastic particles to cement," Gaggino details.
The researcher explains that the process is carried out by crushing the plastics with a mill, then in a common concrete mixer a mixture is made with the portland cement and the additive, which is then placed in a manual block that shapes the bricks. "The process is simple because it is like making blocks of cement and sand, only that the sand is replaced by PET plastic particles," he says.
Among the technical advantages of these bricks it can be mentioned that they are five times more thermally insulating than conventional ground bricks, and also lighter. "A PET brick weighs 1,400 kg, while an earth brick weighs about a kilo more," says Gaggino.
On the other hand, the researcher adds that the foundations of a house built with these bricks are smaller than those of a conventional one, since the house in general is lighter, and, as it has greater thermal insulation, thinner walls can be built . "Instead of making walls of 30 cm, they can be made of 15", he assures.
In addition, the studies carried out indicate that PET and cement bricks have good resistance to fire, since the results of the Flame Spread Test classify it as a Class RE 2 material: combustible material with very low flame spread.
At present these construction components are used for enclosures and not for structural purposes, so work is being done on modifying the surface of PET to increase compatibility with cement, through the addition of chemicals or changes in the production process. , and thus improve the mechanical properties of the components.
Gaggino emphasizes that a PET brick is made from 20 disposable bottles, which highlights the environmental importance of the project, since it can be an alternative to the clay brick that consumes fertile soil, uses firewood from forests, and produces pollution. atmospheric.
We share the Manual for the production and application of PET brick, Collection of Architecture and Environment, CEVE, CONICET:
* These bricks have a national patent obtained in 2008, and a Certificate of Technical Aptitude granted by the Undersecretariat of Housing and Urban Development of the Nation in 2006.