Recent Developments in Lightweight Fibre-Reinforced Concrete: Mechanical Characteristics and Structural Performance – A Review

Lightweight concrete (LWC) has emerged as a viable alternative to conventional concrete due to its lower density, improved thermal insulation, and sustainability benefits. However, its reduced mechanical properties and susceptibility to cracking have limited its structural applications. The incorporation of fibres in lightweight concrete (FRLWC) has been explored to enhance its mechanical performance, durability, and structural integrity. This review highlights key aspects of FRLWC, including workability, modulus of elasticity, ductility, cracking resistance, and overall structural behavior. Studies indicate that fibre reinforcement improves flexural ductility, cracking resistance, and energy absorption, while also influencing the modulus of elasticity based on fibre type and volume fraction. The addition of steel fibres has shown significant enhancement in mechanical properties, whereas synthetic fibres such as polypropylene and polyvinyl alcohol mainly contribute to crack control. Furthermore, research has demonstrated improved post-crack load-bearing capacity and toughness in fibre-reinforced lightweight concrete beams and slabs. Despite these advancements, challenges remain in achieving uniform fibre dispersion and maintaining workability. This paper provides a comprehensive review of the latest developments in FRLWC, addressing its potential for structural applications and identifying areas for future research.