Properties of cellular lightweight high calcium bottom ash-portland cement geopolymer mortar
Cherdsak Suksiripattanapong, Kitsada Krosoongnern, Jaksada Thumrongvut, Piti Sukontasukkul, Suksun Horpibulsuk, Prinya Chindaprasirt
Abstract
In this study, the bottom ash obtained from Mae Moh electrical powerplant was used as a sustainable material in the production of geopolymer cellular lightweight mortar blocks. The mix proportions for the solid content consisted of a sand/binder ratio (S/B) of 1:1, and six different bottom ash/cement (BA/C) ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 with a constant liquid alkaline activator/binder (L/B) ratio at 0.60. Three different Na2SiO3:NaOH (NS/NH) ratios of 80:20, 70:30 and 50:50 were used with four different NaOH concentrations at 8, 10, 12 and 14 molars. To produce air bubbles into the mix, the foam content was set at 0, 1, 2 and 3% by total solid weight. The experimental series consisted of unit weight, porosity, compressive strength, and thermal conductivity at different ages. The results showed that the unit weight of the cellular lightweight bottom ash based geopolymer (CLBAG) mortar depended mainly on the foam content. The lowest unit weight of 11.09 kN/m3 was obtained at the mix with S/B ratio of 1:1, NS/NH ratio of 50:50, BA/C ratio of 100:0, and foam content of 3%. The compressive strength was found to increase with the increasing binder and NS content but decreased with the increasing foam content. The thermal conductivity was found to decrease in proportional to the increasing porosity.