Possibility of producing thermal insulation materials from cementitious materials without foaming agent or lightweight aggregate.

Due to the high increase in the consumption of building energy in the world, it is urgent to develop and use thermal insulation materials to limit the demand of energy. In this article, the possibility of producing thermal insulation plasters from common cementitious materials such as fly ash (FA), metakaolin (MK), and silica fume (SF) without employing any foaming agent or lightweight aggregate was investigated. Either cement or gypsum was used as a binder material. Eight different types of plaster based on different pozzolanic materials were investigated and compared with the traditional cement mortar plaster (TC). The compressive strength, bulk density, total porosity, thermal conductivity, and thermal resistance were measured. The results showed that it is possible to produce thermal insulation plasters based on pozzolanic materials without including foaming agent or lightweight aggregate. The obtained insulating plasters exhibited low density (888.75-1575.63 kg/m), high porosity (39.5-57.75%), low thermal conductivity (0.30-0.48 W/mK) and suitable compressive strength. Using gypsum as a binder material was better than cement for insulation purposes. SF showed the highest insulation efficiency followed by FA and MK.