Supercritical carbonation of lightweight aggregate containing mortar: Thermal behavior

Lightweight concrete shows good insulation properties, depending on several parameters such as mix design and aggregate type. Perlite aggregate is one of the most effective aggregates for such a purpose, mainly because of its low thermal conductivity (0.04 W/m.oC), but is not available globally. This paper explores the potential use of another source of thermal efficient aggregate, vermiculite (0.058 W/m.oC) which is available in Brazil and other countries where perlite is absent. Cylindrical samples were cast by using two lightweight aggregates, perlite and vermiculite, and treated with supercritical carbon dioxide. Supercritical carbonation (SCC) of concrete can improve mechanical, thermal and durability features. In this paper, the effect of SCC on the thermal behavior of lightweight mortars was investigated with regards to physical and microstructure features and thermal behavior due to cooling.