Fly ash based lightweight wall materials incorporating expanded perlite/SiO2 aerogel composite: Towards low thermal conductivity

Abstract

Fly ash based lightweight wall materials (LWM) incorporating expanded perlite (EP)/SiO2 aerogel composite were successfully prepared towards low thermal conductivity. As a functional padding, silica aerogel with density of 119 kg/m3 and thermal conductivity of 0.0277 W/(m·K) was synthesized by a two-step catalytic method and drying procedures under mild conditions. EP/SiO2 aerogel composite was further synthesized via impregnation method to load the SiO2 aerogel on the surface of EP. The bulk density and compressive strength of the prepared fly ash based LWM incorporating the optimized 20% EP/SiO2 aerogel composite reached 335 kg/m3 and 0.88 MPa, respectively, and the thermal conductivity was significantly reduced to 0.050 W/(m·K). Hence, the fly ash based LWM consisting of EP/SiO2 aerogel composite could be efficiently useful as building insulation thermal materials.