A group of Vietnamese high school students have developed bricks made entirely from plastic waste that meet the country’s construction material standards.
Six 11th graders from Cao Thang High School in Thua Thien-Hue Province, located in central Vietnam, have created four different models of plastic bricks, also called polymer bricks, two of which meet the national standards for cement bricks permitted to be used for construction.
Practicality is priority
Polymer bricks are ones made of four main materials - cement, sand, blended plastic, and water.
After the ingredients are mixed together, the mixture is shaped with a mould and left in the sun to dry for a month.
Polymer bricks do not require baking which helps eliminate gas emissions during the production process.
In order to meet Vietnam’s national standards for bricks, four different models with varied ratios of materials were made.
The amount of plastic in each brick ranges from 300 to 600 grams per 7-to-10-kilogram product.
The size of the brick is 100x185x280 millimeters.
All four models were tested by a local cement manufacturer who found that two matched the country’s current standards.
One of the suitable models could be used for all constructions, while the others can only be used for smaller projects.
“The bricks are not baked so the process minimizes gas emissions,” Nguyen Tran Tien, the group’s head researcher, said.
“Using blended plastic helps minimize plastic waste. The new technique also limits the amount of sand used for brick production so it also lowers sand exploitation which causes erosion.
"Despite that, there is no additional cost required and the quality remains the same.”
Inspired by UN report
The students said they originally began working on the project with the intention of finding a solution to the enormous amount of untreated plastic waste currently present in the country, an issue exacerbated by the heavy dependence on plastic bags and cups.
Only 27 percent of plastic bags are properly treated, Thang said, citing the most recent UN report.
The project must ensure three things – environmental safety, practicality, and feasibility, he added.
“Many previous solutions have proven beneficial but just aren’t practical for use in daily life,” he explained.
In order to start the project, each of the group members spent several hours after school collecting plastic waste from trash bins and asking neighboring households for plastic waste.
The trash was then cleaned and cut into small pieces before being mixed with cement, sand, and water.
The process was challenging because it took a long time and none of the group members had had experience in manufacturing and waste treatment.
“If the product is used by consumers it will become a valuable resource with many advantages,” one of the researchers said confidently.
“We would no longer have to think about new ways to treat plastic.”