Lightweight Cement-Based Composites Incorporating Hollow Glass Microspheres: Fresh and Hardened State Properties

This research aims to develop a lightweight cementitious composite with satisfied mechanical and good thermal insulating properties. Two different types of hollow glass microspheres were used as lightweight aggregates and were substituted with fine aggregate by 10, 20 and 40% by volume. The rheological, physical, mechanical and microstructural properties of the resulting HGM-incorporated composites are investigated. The results showed that physical and mechanical properties of individual HGM particles plays a dominant role on the properties of lightweight cement mortars. HGM addition provided reductions up to 20% in the density and 45% in the thermal conductivity values of mortars compared to the reference. The optimum HGM ratio is suggested as 20%, which provides benefits such as reduced density and improved thermal insulation capability without causing significant reduction in compressive strength. It was concluded that HGMs can be used in the lightweight cementitious mortar production which have great potential in building applications to reduce the heating energy consumption.