Thermal conductivity of lightweight foamed concrete filled fly ash

Abstract

Wall is the wider component of high-rise building to exposed the sunshine than roof. The building wall in tropical countries receives the solar heat all day and it makes temperature rise of its room and becomes less comfortable. Therefore, a wall with good thermal insulation is needed for buildings in tropical countries. Lightweight foamed concrete (LFC) can be used as a wall brick substitution as well as thermal insulator. The experimental research about LFC was investigated using FA and foam content to the thermal conductivity of LFC. The investigations were performed through the measurement of thermal conductivity, material density, and observation to the morphology of LFC surface. The LFC samples were varied in volume fraction of foam and FA in mortar. The result shows that the increase in volume fraction of foam in all variations of FA content decreases its thermal conductivity. In contrast, the increase of FA content in LFC results in an increase in thermal conductivity until 45 wt% of FA content, then it decreases as the addition of FA. Thus, the optimum thermal conductivity of the LFC was obtained by FA of 45 wt%. The relationship between thermal conductivity and LFC density shows that any increase in LFC density resulted in an increase in thermal conductivity. Otherwise, any decrease in LFC density resulted in a decrease in thermal conductivity.