Sustainable Construction Material Made from Recycled Plastic Waste Shows Promise

Strategic Insights -

Researchers at the Dar es Salaam Institute of Technology in Tanzania have investigated the feasibility of using recycled plastic waste in the production of plastic-sand paving blocks as a sustainable construction material. The study found that a mix ratio of 40% plastic to 60% sand offers the best performance, making plastic-sand paving blocks a promising alternative to conventional materials. This innovation has the potential to contribute to sustainable waste management and eco-friendly construction.

Key Takeaways:

  • The research investigated the use of recycled plastic waste in the production of plastic-sand paving blocks as a sustainable construction material.
  • Six mix ratios were formulated, varying the plastic waste content from 10% to 60% by weight.
  • The results showed that water absorption decreased with higher plastic content, with PSP-R10 (10% plastic, 90% sand) exhibiting the highest absorption (8.6%), while PSP-R60 (60% plastic, 40% sand) had the lowest (0.4%).
  • Bulk density varied across the mixes, with PSP-R50 showing the highest density (1070 kg/m3) and PSP-R60 showing the lowest density (734 kg/m3).
  • Compressive strength peaked at 74.91 MPa for PSP-R40 (40% plastic, 60% sand), demonstrating an optimal balance between strength and flexibility.
  • Excessive plastic content reduced strength, with PSP-R60 dropping to 27.24 MPa.
  • The research concluded that a 40% plastic-to-60% sand ratio offers the best performance, making plastic-sand paving blocks a promising alternative to conventional materials.

Statistics:

  • Water absorption decreased from 8.6% to 0.4% as plastic content increased from 10% to 60%.
  • Bulk density ranged from 734 kg/m3 (PSP-R60) to 1070 kg/m3 (PSP-R50) across the mixes.
  • Compressive strength peaked at 74.91 MPa for PSP-R40 (40% plastic, 60% sand).
  • PSP-R60 showed a significant reduction in compressive strength to 27.24 MPa due to excessive plastic content.

Sources:

  • Investigation of plastic-sand paving blocks: A sustainable solution using recycled plastic waste. Hybrid Advances, 2025, 10():100492. (Elsevier).
  • NewsRx. Dar es Salaam Institute of Technology Researcher Details New Studies and Findings in the Area of Sustainability Research (Investigation of plastic-sand paving blocks: A sustainable solution using recycled plastic waste). Ecology, Environment & Conservation. September 12, 2025; p 47.