Aerogel based thermal insulating cementitious composites: A review

With the increase in global warming, the demand for more sustainable and thermal insulating cement-based lightweight composite increases. From the past few decades, researchers worldwide have carried out extensive research on lightweight concrete using various lightweight aggregates. The use of aerogel as an aggregate in lightweight concrete is the most promising building application these days. With the exceptional characteristics of thermal insulation, ultra-low density, high adsorption, high surface area, aerogel shows a remarkable behavior. Although, the poor mechanical characteristics and high cost of aerogel have negative effects on the aerogel-incorporated concrete. This article is aimed to present a complete in-depth review of aerogel incorporated cementitious materials in terms of production/synthetisation, fresh rheology and proportioning, mechanical, microstructural, and durability properties, including water absorption, capillary water absorption, fire resistance, and exposure to elevated temperature, thermal insulation properties, and economic perspectives of aerogel. Particular emphasis has been given to study the hygrothermal behavior of aerogel-based cement composites. In addition, the present investigation gives a summary of case studies that have been performed for aerogel-based cementitious products used in buildings. The study suggests the promising future of aerogel as lightweight thermal insulating composites with sufficient mechanical properties.