THERMAL CONDUCTIVITY OF REINFORCED GEOPOLYMER FOAMS

Abstract

Reinforced geopolymer foams were studied in this work as potential building materials. It has been widely assumed that for a given thermal conductivity [λ - W.m-1.K-1], geopolymer foams can have a lighter density than other materials. The study sought to test this assumption by comparing the thermal conductivity between geopolymer foams. The thermal conductivity λ was measured using an ISOMET 2014 device. In all the experiments, the geopolymer foams were obtained by adding aluminium powder and several combinations: silica fume and fine sand reinforced by short basalt fibres. Curing was carried out at room temperature and then in a furnace at 70 °C. After the curing process, the properties of the samples were tested at 7 and 28 days. The results show that the thermal conductivity, porosity, compressive strength, flexural strength and density for all of the tests ranged in the following values: 0.13 - 0.359 W.m-1.K-1; 41.8 - 62.5%; 1.94 - 9 MPa; 0.96 - 2.93 MPa; 546 - 1028 kg /m3, respectively. It was proven that the filler in the geopolymer foams has a significant influence on the mechanical and physical properties of the tested samples.

Keywords

• geopolymer
• porosity
• aluminium powder
• basalt fibres
• metakaolin
• silica fume