A Review of Lightweight Concrete in Civil Engineering

Lightweight concrete, defined as concrete with a dry density below 2000 kg/m³, has become increasingly prominent in modern advanced concrete technology and constructions due to its low density, superior thermal insulation, and sustainability benefits owing to the use of industrial by-products and waste materials in the process of its production. This study presents a comprehensive overview of lightweight concrete, covering its historical development, material composition, and performance characteristics. The fresh properties, such as workability, slump, and water absorption, are discussed alongside its mechanical properties, including compressive, flexural, and tensile strength; modulus of elasticity; ductility; and fatigue resistance. The durability characteristics, such as water and chemical permeability, freeze-thaw resistance, carbonation, shrinkage behavior, and reinforcement corrosion, are also evaluated. In addition, the microstructural characteristics, including density, porosity, and aggregate-cement matrix interfacial transition zone (ITZ), are examined using SEM, XRD, TGA, and FTIR analyses. The study also considers the environmental performance of lightweight concrete,