improvement of recycled concrete aggregate properties by polyvinyl alcohol

This study examines liquid polyvinyl alcohol (pva) impregnation of recycled concrete aggregate (rca) to refine pore structure and evaluate its influence on the fresh and hardened properties of companion concretes, using natural aggregate concrete as the benchmark. aggregates were pretreated at progressively higher pva dosages and characterized for specific gravity, water absorption, and gradation, and concretes with untreated and pva-treated rca were assessed for slump, water absorption, compressive strength, and drying shrinkage. the investigation was intentionally designed for non-structural concrete applications such as paving blocks, curbs, and lightweight elements, where durability and sustainability are prioritized over high strength. results indicated that increasing pva dosage enhanced aggregate density and reduced water absorption at higher levels (10%), but also caused trade-offs in workability and mechanical strength. workability improved at 6% pva but declined at higher contents, while compressive strength decreased at 6–8% and partially recovered at 10%. drying shrinkage increased slightly with pva addition. overall, pva pretreatment improved aggregate densification and moisture resistance but required dosage optimization for practical use in durable, non-structural rca concretes aimed at sustainable resource utilization.