Comparative study of the mechanical and thermal properties of lightweight cementitious composites

Lightweight concrete and cementitious composites are increasingly studied by researchers due to their advantageous performance in reducing structural load and building's operational energy consumption. In this research, a comprehensive and thorough study was carried out to investigate the effects of different lightweight fillers on both the mechanical and thermal properties of lightweight cementitious composites, or LWCCs. Four different types of lightweight fillers (LWFs) including expanded polystyrene (EPS) beads, dry-expanded thermoplastic microspheres (ETM), hollow glass microspheres (HGM), and fly ash cenospheres (FACs) are studied in conjunction with various particle sizes, shell wall thickness, and proportions. Both mechanical and thermophysical properties were tested for these LWCCs after 28-day curing. The results indicated that the thermal property of LWCC is mostly governed by the volume fraction of LWFs and it can be accurately predicted by the Felske equation, whereas the mechanical properties are heavily affected by the type and property of LWF particles included. It was revealed that most fly ash cenospheres (FAC) and hollow glass microspheres (HGM) with higher density are suitable for producing LWCC materials that may be used for structural applications, whereas lower density HGMs and LWFs with soft polymer shell are more suitable for nonstructural thermal insulating components.