Recycled PET Sand for Cementitious Mortar.

Area of Science:

• Materials Science
• Environmental Engineering
• Civil Engineering

Background:

• Cementitious materials production significantly impacts the environment through clinker calcination and non-renewable resource extraction.
• River sand is a crucial non-renewable resource commonly used in cementitious materials.

Purpose of the Study:

• To evaluate the feasibility of replacing river sand with recycled PET (polyethylene terephthalate) sand in cementitious materials.
• To assess the impact of PET sand incorporation on the fresh and hardened properties of mortars.
• To determine the optimal replacement level for sustainable material development.

Main Methods:

• Mortar specimens were prepared with PET sand replacing river sand at 10%, 20%, and 30% levels.
• Fresh state properties tested included consistency, air retention, density, and incorporated air.
• Hardened state properties evaluated were compressive strength, flexural strength, density, capillarity, and water absorption.

Main Results:

• PET sand is viable up to a 10% replacement level, showing improvements in mechanical properties without compromising workability or incorporated air.
• Higher replacement levels (20% and 30%) resulted in excessive property degradation, particularly in workability and incorporated air.
• A 30% PET sand composition exhibited an incorporated air content of 24%, negatively impacting hardened properties and rendering it unusable above 20%.

Conclusions:

• Recycled PET sand can be utilized as a partial substitute for river sand in cementitious materials, contributing to sustainable development.
• The optimal replacement level for PET sand is up to 10% to maintain desirable material properties.
• This approach reduces the reliance on non-renewable river sand extraction, aligning with environmental conservation goals.