Open AccessThe Effect of Sodium Carbonate on the Fresh and Hardened Properties of Fly Ash-Based One-Part Geopolymer
Author(s) -
Ooi Wan-En,
Liew Yun-Ming,
Li-Ngee Ho,
Mohd Mustafa Al Bakri Abdullah,
Ong Shee-Ween
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/864/1/012197
Subject(s) - geopolymer , fly ash , compressive strength , sodium carbonate , materials science , curing (chemistry) , porosity , alkali metal , anhydrous , sodium hydroxide , sodium , nuclear chemistry , chemical engineering , chemistry , metallurgy , composite material , organic chemistry , engineering
One-part geopolymer utilized dry activator(s) which undergo geopolymerization by “just add water” mechanism. There are wide varieties of dry binders to develop one-part geopolymer. This work presents an investigation of fresh and hardened properties of fly ash-based one-part geopolymer activated by mixture of anhydrous sodium metasilicate (Na 2 SiO 3 ) with sodium carbonate (Na 2 CO 3 ). The ratios of alkali activator-to-fly ash (AA/FA) were set as 0.15, 0.20 and 0.25. The substitution of Na 2 CO 3 was set as Na 2 SiO 3 /Na 2 CO 3 ratio of 1. Setting time of fresh one-part geopolymer was examined through Vicat needle apparatus. Porosity, compressive strength and microstructural properties of developed specimens were also analyzed after 28 days of curing. The result showed that the partial substitution of Na 2 CO 3 resulted in a shorter setting time and lower porosity. Besides that, the one-part geopolymer activated by the mix of Na 2 SiO 3 and Na 2 CO 3 achieved 78.23 MPa at AA/FA ratio of 0.20. The findings suggest that Na 2 CO 3 is a potential alkali activator for one-part geopolymer.