Fresh and Mechanical Properties of Lightweight Aggregate Concrete with Scrap Steel Fiber Reinforcement and Bagasse Ash

A sustainable concrete solution was developed by partially replacing aggregates and cement with lightweight plastic aggregates (LWPA) and bagasse ash, respectively. Three types of mixes were studied: (i) concrete with 10-30% cement replaced by bagasse ash (BA), (ii) Bagasse ash concrete mix with scrap steel fiber, and (iii) Bagasse ash concrete with scrap fiber and 10-50% lightweight aggregate. The addition of bagasse ash positively influenced the fresh properties of concrete. However, workability decreased by 56% with the incorporation of scrap fibers and lightweight aggregate compared to the control mix. Slump values reduced in concrete mixes containing plastic aggregate (PA) due to mortar accumulation in voids within the hollow aggregate, significantly diminishing workability. The density of concrete decreased with bagasse ash and lightweight aggregate inclusion, aiding in reducing structural dead weight. However, the strength decreased notably with 30% replacement using hollow lightweight plastic aggregate. Voids in concrete specimens increased with LWPA percentage. Observations from fresh and hardened concrete tests suggest that plastic aggregate, bagasse ash, and scrap fiber can effectively replace up to 20% of gravel aggregate.