Mechanical Properties and Thermal Conductivity of Lightweight Foamed Geopolymer Concretes

Abstract

Foamed geopolymer concretes have a better performance in the thermal insulation properties compared to normal geopolymer concretes. In this research, lightweight aggregate geopolymer concretes was incorporated with different percentage of foaming agents (hydrogen peroxide). Compressive strength and thermal conductivity were measured. From results obtained, increased H2O2 contents will decrease the strength of lightweight foamed geopolymer concretes. Lightweight aggregate foamed geopolymer concretes (LWAFGC) with foaming agent content of 0.2wt.% obtained the highest strength of 19.601 MPa. Furthermore, Increased of H2O2 contents also will decrease the thermal conductivity of lightweight foamed geopolymer concretes. Lightweight foamed geopolymer concretes with 2wt.% H2O2 gave the good thermal insulating behavior when the thermal conductivity value recorded the lowest value compare to other wt.% of H2O2 content. The thermal conductivity value of lightweight foamed geopolymer concretes with 2wt.% of H2O2 was 0.072 W/m. K while, the thermal conductivity of other mixtures ranged between 0.077 W/m. K to 0.087 W/m. K., respectively.

Thermal conductivity of several geopolymer composites and discussion of their formulation

“…Metakaolin GPs are inherently insulating as a result of their amorphous and nanoporous structure 23–25 . Most work reported on metakaolin GP composite thermal conductivity has involved adding materials or structural features, including glass microspheres, 26 polystyrene (PS), 27,28 cork, 29 mineral particles, 30 rubber disks, 31 and induced porosity, 32–38 to improve their insulating ability. On the other hand, only few fillers have been evaluated in metakaolin GP composites for increased thermal conductivity (quartz, 39 SiC, 40 graphene nanoplatelets [GNPs], 41 carbon nanotubes [CNTs], 42 diamond, 43 and calcite 44 ).…”

Development of Foam Fly Ash Geopolymer with Recycled High-Density Polyethylene (HDPE) Plastics

“…After subjecting each sample to an average temperature of 25.52 °C, the 0.25% HDPE addition lowered the thermal conductivity by almost 6%, while the 0.50% HDPE addition resulted in the same value as the reference mix. According to Fatimah et al [58], foam geopolymer's thermal properties depend on its porosity structure. As the volume of pores increases, the density will decrease, and lower thermal conductivity may be obtained.…”