STRUCTURAL PERFORMANCE OF LIGHTWEIGHT AGGREGATE CONCRETE BEAMS INCORPORATING PUMICE OR VOLCANIC AGGREGATES UNDER FLEXURAL LOADING AND SERVICEABILITY LIMIT STATES

Abstract

Lightweight aggregate concrete (LWAC) incorporating pumice and volcanic aggregates presents a sustainable solution for modern construction by reducing structural dead loads while maintaining adequate mechanical performance. This comprehensive systematic review synthesizes 40+ peer-reviewed studies examining the flexural and serviceability behavior of LWAC beams fabricated with pumice or volcanic aggregates. The review demonstrates that pumice LWAC achieves compressive strengths of 20-42 MPa and flexural strengths of 3.2-4.5 MPa, with densities ranging from 1650-2380 kg/m³, depending on replacement levels. Critical findings reveal that serviceability limit state (SLS) performance, particularly deflection control and crack width management, represents the governing design criterion for LWAC beams. At service load levels (0.4-0.5 of ultimate capacity), mid-span deflections range from 6.2-8.5 mm with maximum crack widths of 0.15-0.31 mm, meeting ACI 440 and Eurocode 2 limits. The incorporation of steel fiber reinforcement (0.5-1.5% by volume) significantly improves post-cracking behavior, increasing ultimate load capacity by 13.7%-45.3% and ductility indices by 22%-89%. Mineral admixtures, particularly silica fume and slag combinations, enhance both strength and durability properties. Durability assessments under freeze-thaw, sulfate, and acid attack conditions demonstrate performance comparable to normal-weight concrete when supplementary cementitious materials are incorporated. The review concludes that properly designed LWAC beams with pumice or volcanic aggregates can meet structural, serviceability, and durability requirements, offering economic and environmental benefits while reducing construction weight by 20-25% compared to normal-weight concrete.