Recycled-plastic bricks are usually tested in only one direction. An Indonesian team tested them both ways, and the strength did not hold up the way the headline figure suggests.
Bricks made from recycled plastic are usually tested only one way, pressed straight down, which does not reflect how a brick actually sits inside a wall. Etty Sisdiana and her team at Indonesia's National Research and Innovation Agency tested the same bricks both ways, the way they are stacked and the way they are loaded sideways, to see if the strength held up in both directions.
Some reported findings are:
- Bricks with 50 per cent plastic waste reached 30.15 MPa when loaded sideways, stronger than ordinary bricks at 22.74 MPa
- The same bricks dropped sharply in strength when loaded the way they would actually sit in a wall
- A 40 per cent plastic mix was identified as the safest overall balance of strength and sustainability
This paper was published in our affiliated journal Future Cities and Environment. Read the full article