Influence of calcium compounds on the mechanical properties of fly ash geopolymer pastes

摘要

The influence of calcium compounds (CaO and Ca(OH)_2) on the mechanical properties of fly ash based geopolymers has been studied. Calcium compounds were substituted in fly ash at 1,2 and 3 wt%, respectively. Curing of the geopolymers was performed at ambient temperature (20℃) and 70℃ Addition of calcium compounds as a fly ash substitute improved mechanical properties for the ambient temperature cured samples while decreasing properties for the 70 C cured samples. Seven days compressive strength of the ambient temperature cured samples increased from 11.8 (2.9) to 22.8 (3.8) MPa and 29.2 (1.1) MPa for 3% CaO and 3% Ca(OH)_2 additions, respectively.