Mechanical properties of polymer concrete made with recycled PET and recycled concrete aggregates

The purpose of this study was to solve some of the solid waste problems posed by plastics and concrete demolition. To this end, we evaluated the mechanical properties of polymer concrete, in particular, polymer concrete made of unsaturated polyester resins from recycled polyethylene terephthalate (PET) plastic waste and recycled concrete aggregates. The strength and the resistances to acid and alkali compounds of the polymer concrete were measured by varying the coarse and fine aggregate ratio and resin content. Three main observations followed the results. First, we found that the strength of polymer concrete made with a resin based on recycled PET and recycled aggregate increases with increasing resin content; however, beyond a certain resin content, the strength does not change appreciably. Second, the stress–strain curves of polymer concretes with 100% natural aggregate and 100% recycled aggregate exhibited different failure mechanisms of the compressed materials. Third, with respect to acid resistance, the polymer concrete at a resin content of 9% was nearly unaffected by HCl, whereas the polymer concrete with 100% recycled aggregate showed poor acid resistance. Unlike acid, alkali compounds did not seem to attack the polymer concrete with 100% recycled aggregate as observed from the weight change and the compressive strength.