Evaluation of the fresh and hardened properties of high-strength self-compacting concrete incorporating coarse-sized shredded polyethylene terephthalate particles

Increasing volume of waste drinking bottles with polyethylene terephthalate (PET) based has become a serious environmental concern. In the present research, shredded PET particles (SPPs) as partial substitute for sand (RS) and gravel (RG) contents by 2% to 12% were incorporated into self-compacting concrete (SCC). Concrete mixes were fabricated with three cement contents where the other mix parameters were fixed. Concretes with less self-compact-ability resulted in hardened performance degradation especially as an increment in RG into the leaner mixes. Substitution of sand with SPPs was found to give the better concrete properties. Elastic modulus (Ec) decreased with increments in substitution which implied the more ductile failure in PET-SCC compared to plain SCC. Moreover, perfect correlation between fresh properties and compressive strength (fc) was established. Strong relationships for Ec, splitting tensile strength (ft), and flexural strength (ff) versus fc were also found. For high-strength PET-SCCs with 2% RS, the maximum improvements in fc, ft, ff by 6, 9, and 15%, were obtained, respectively. Tolerable ranges of water absorption (WA) ≤ 3.5% and penetration depth (Dp) ≤ 20 mm were also found for PET-SCCs incorporating 10% RS with high level of fracture energy, fc > 50 MPa and improved ductility by 30%.