Sustainable Cementitious Composites Reinforced with Recycled PET/PP Polymer Blends

Abstract

This study evaluated the effect of polymer reinforcement obtained from a PET/PP (polyethylene terephthalate/polypropylene) blend, in a 50/50 (% by weight) ratio, incorporated into a cementitious matrix at contents of 0.5%, 0.75%, and 1.0% (% by weight). The polymers used were sourced from industrial packaging waste, aimed at the reuse of materials with good mechanical properties and the production of a more sustainable, efficient, and low-cost concrete. Polymeric blends stand out due to their favorable cost benefit ratio and the possibility of tailoring their physical and chemical properties for different applications. The specimens were subjected to diametral compression tests to analyze the mechanical behavior of concrete reinforced with the PET/PP blend. The results indicated that the addition of polymer reinforcement influenced the mechanical performance of the material, with the 0.75% content showing the highest failure load (11.32 MPa) compared to the reference concrete (10.15 tons). For the 1.0% content, performance was like that of reference concrete, indicating that higher addition levels may not lead to proportional strength gains. These findings suggest the existence of an optimal PET/PP blend content, at which improved interaction with the cementitious matrix contributes more effectively to concrete reinforcement.