USE OF POLYETHYLENE TEREPHTHALATE (PET) PLASTIC WASTE IN MORTAR

The increasing generation of plastic waste and its low recycling rate constitute a major worldwide environmental and economic challenge. With a view to sustainable recovery, this study examines the incorporation of polyethylene terephthalate (PET) plastic waste as a partial substitute for sand in mortars. The aim is to evaluate the impact of these additions on the physical and mechanical properties of the material, with a view to developing more sustainable and environmentally-friendly cementitious composites.PET fibers were introduced as a volumetric replacement of sand at rates of 0.5%, 1%, 1.5%, and 2%. Mortars were prepared with cement dosages ranging from 250 g to 500 g (in 50 g increments) and four water/cement (W/C) ratios per dosage. The experimental program included tests on fresh density, water absorption coefficient, flexural strength, and compressive strength.The results reveal that the fresh mortar density remains relatively stable despite the gradual addition of PET. The water absorption coefficient generally decreases with higher WC ratios but increases with higher cement dosages. In terms of mechanical performance, flexural performance is generally lower after the incorporation of PET. On the other hand, compressive strengths are improved for incorporation rates of 1, 1.5 and 2, with measurable gains compared with control mortars. Even in cases of reduction, the performance loss does not exceed 1.5. These results indicate that the controlled addition of plastic fibers from PET waste may be a promising way of manufacturing composite mortars with a reduced environmental impact.