Comprehensive review on nanomaterials incorporated in lightweight concrete

The application of lightweight concrete (LWC) has advanced sustainable construction. However, its application in construction is constrained by its low strength, poor toughness, and insufficient durability. Nanomaterials, known for their superior physical and mechanical characteristics, are extensively utilised in cement-based composites. A minimal quantity of nanoparticles can markedly improve the overall performance of LWC without diminishing its weight benefit.This review highlights various nanomaterials used in LWC and their effects on LWC's workability, mechanical, and durability properties. Scanning electron microscopy analysis reveals the performance enhancement mechanisms of different nanomaterials in LWC. The review further discusses current research limitations and suggests future applications. Results indicate that adding nano SiO₂, carbon nanotubes (CNTs), graphene oxide (GO), and nano TiO₂ reduces LWC's workability. All nanomaterials (including nano SiO₂, CNTs, GO, nano TiO₂, nano metakaolin, nano palm oil fuel ash and nano palm oil clinker powder) enhance mechanical properties, with GO and CNTs significantly improving flexural strength. Additionally, nanomaterials increase LWC density, reduce porosity, especially macro-pores, and enhance durability. This first comprehensive review of nanomaterial applications in LWC aims to build on the research achievements in this field to broaden the scope of future high-performance LWC used in sustainable building.