Quasi-static strength and long-term characterisation of LC3 concrete: Effect of recycled fine aggregate and polypropylene fibre

The adoption of limestone calcined clay cement (LC 3 ) globally is growing rapidly due to its environmental benefits, durability performance, and economic merits. While numerous studies have examined the mechanical and durability properties of LC 3 concrete, research on its time-dependent deformation behaviour remains limited. This study explores the impact of recycled fine aggregate and micro-synthetic polypropylene fibre on the quasi-static properties, microstructure, and time-dependent deformation characteristics of LC 3 concrete to bridge this gap. Six concrete mixes were investigated, including a control mix, LC 3 , fibre-reinforced LC 3 , and LC 3 mixes incorporating 25 %, 50 %, and 100 % recycled fine aggregate. Specimens derived from these mixes were tested for compressive strength, flexural strength, splitting tensile strength, modulus of elasticity, drying shrinkage, and compressive creep. Experimental findings indicate that LC 3 concrete exhibits mechanical performance comparable to that of Portland cement concrete, with improved drying shrinkage and creep compliance. These results suggest that LC 3 is a viable alternative for construction applications and establish a reference for future studies on the compressive creep of LC 3 concrete. • Drying shrinkage and compressive creep of LC3 and recycled fine aggregate-LC3 concrete is reported for the first time. • Influence of stress levels, fibre and proportion of recycled fine aggregate is studied. • Lesser drying shrinkage and creep are reported for LC3 concrete compared to Portland cement concrete up to 210 days. • 100 % recycled aggregate-LC3 concrete outperformed other mixes showing lesser creep.