Behavior and properties of ultra-lightweight concrete with foamed glass aggregate and cellulose fibres under high temperature loading

This study deals with the possibility of the utilization of composite materials with aggregate based on foamed glass bonded with cement. The idea of this study is to effectively use the advantages of the foam glass-based aggregate with a very low bulk density below 160 kg/m3 and a thermal conductivity of 0.069 W/(m.K). Foam glass-based aggregate is mainly made from waste glass that can no longer be recycled and used for the production of pure glass products. The purpose of the research is to produce an ultra-lightweight concrete (ULWC) with high resistance to high temperatures, high temperature attenuation and minimal ecological impact. In an experimental study, glass foam aggregate was bonded with a cementitious sealant with cellulose fibres to obtain an ultra-lightweight concrete with a bulk density in the range of 400–550 kg/m3, a thermal conductivity of lower than 0.1 W/(m·K) and compressive strength in the range of 0.9–2.1 MPa. The ultra-lightweight concrete was exposed to high temperature loading according to standardized fire curve and the effect of high temperature on the microstructure of the concrete was inspect by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The ultra-lightweight concrete with foam glass aggregate reaches high resistance to high temperatures up to 1000 °C as well as a large thermal attenuation over the height of the specimen. Other main advantages include the extremely low weight, which results in minimal static load on the structures due to its own weight, and the use of waste glass for the production of aggregates, which leads to a reduction in the burden on the environment. •The properties of the used foamed glass aggregate (FGA), cement and recycled cellulose microfibers are studied and summarized.•Development of ultra-lightweight concrete (ULWC) with FGA with bulk density up to 550 kg/m3 and thermal conductivity lower than 0.1 W/(m·K).•35–75% increase in ULWC compressive strength using recycled cellulose microfibers up to 30 μm thickness.•The response of the ULWC in contact with extremely high temperature, the temperature profile of ULWC under fire loading.