Open AccessOne-part alkali activated slag using Ca(OH)2 and Na2CO3 instead of NaOH as activator: more excellent compressive strength and microstructure
Author(s) -
Shiming Zhou,
Chunqin Tan,
Yuan Gao,
Yang Li,
Shenglai Guo
Publication year - 2021
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ac16f4
Subject(s) - compressive strength , sodium hydroxide , sodium carbonate , alkali metal , slag (welding) , calcium hydroxide , materials science , sodium , hydroxide , inorganic chemistry , metallurgy , chemistry , calcium carbonate , chemical engineering , composite material , organic chemistry , engineering
In this paper, sodium carbonate and calcium hydroxide instead of sodium hydroxide used as composite activators, and slag are applied to prepare one-part alkali-activated slag. Furthermore, the properties of the slag activated by sodium hydroxide are compared. The compressive strength, XRD, TGA, MIP, and SEM analysis of the two systems are performed. The results show that the one-part alkali-activated slag prepared from sodium carbonate and calcium hydroxide has a superior compressive strength against the slag activated by sodium hydroxide. It is also found that the hydration speed of the sodium hydroxide activated slag is faster, and thus the higher compressive strength of the one-part alkali-activated slag is not caused by the hydration speed. The hydration of one-part alkali-activated slag produces a certain amount of calcium carbonate, resulting in a lower porosity in comparison with the slag activated by sodium hydroxide, which may be the reason for the better compressive strength of one-part alkali-activated slag.