Bricks containing 20-50% plastic waste were tested under horizontal and vertical compression after 3, 7 and 10 days. Horizontal strength rose with plastic content, reaching 30.15 MPa for the 50% mix at day 10 versus 22.74 MPa for conventional brick. Vertical strength remained only 1.08-1.22 MPa, below the 2.48 MPa control. A composite orientation-sensitive index therefore selected the 40% mix as the better balance.
Key findings
- Horizontal strength reached 30.15 MPa in the 50% mix. • Vertical strength stayed low at 1.08-1.22 MPa. • The proposed two-orientation index favored the 40% mix.
Why this matters globally
The study shows how single-direction testing can overstate waste-based masonry performance and proposes a more application-oriented selection method.
Thai researcher contribution
Researchers linked to Thailand’s National Science and Technology Development Agency contribute to circular construction-material research.
Limitations to consider
Laboratory curing lasted only 10 days; durability, fire, moisture, leaching, mortar bonding and full-scale wall behavior remain untested.