Investigation of waste plastic fiber and grape extract as natural admixtures to enhance the fresh and mechanical properties of roller compacted concrete

This experimental study examines the effects of grape extract and waste plastic fibers as additives in roller compacted concrete (RCC). The research assesses the impact of varying fiber contents (3.15, 6.3, and 9.45 kg/m³) with a fixed grape extract proportion (0.4% by cement weight) on RCC’s water absorption, compressive strength, tensile splitting strength, flexural strength, and microstructure. Results show that grape extract enhances mix compaction and smoothness. A combination of grape extract and waste plastic fibers (Rccp-0.4G-200 pvc) reduces water absorption. Moderate amounts of waste plastic fibers with grape extract improve concrete strength, particularly at later curing ages (28 and 90 days), although higher fiber content can hinder strength development. The additives also improve tensile splitting strength, with Rccp-0.4G-200 pvc showing optimal performance. Flexural strength tests confirm that this combination enhances structural performance, achieving the highest flexural strength. FSEM analysis reveals that waste plastic fibers form a reinforcing network, enhancing toughness and crack resistance, while grape extract aids hydration and reduces porosity. Overall, the findings suggest that a balanced mix of waste plastic fibers and grape extract improves water resistance, strength, and durability, with potential for further optimization to maximize performance.