Properties of self-compacting lightweight concrete containing recycled plastic particles

•Recycled plastic particles are used in self-compacting lightweight concrete (SCLC).•Workability of SCLC is improved by replacing sand by plastic particles.•Strength of SCLC is increased by replacing sand by plastic particles.•Denser plastic-paste interfacial zone is got with relatively low plastic content. This work is aimed to study the effect of incorporating recycled modified polypropylene (PP) plastic particles on the workability and mechanical behavior of self-compacting lightweight concrete (SCLC). Four replacement levels (10%, 15%, 20% and 30%) of sand by plastic by volume were introduced. The slump flow value is improved with an increase in the sand substitution. The viscosity of fresh SCLC is reduced and the passing ability is improved with the replacement level up to 15%. Both the dry bulk density and elastic modulus of SCLC decrease with an increase in sand replacement. The compressive strength, splitting tensile strength and flexural tensile strength are increased with the replacement level up to 15%. A microscopic study on the plastic-paste interface was performed.