This article investigated the compressive strength and drying shrinkage characteristics of low/medium/high calcium-containing alkali-activated materials modified with well-dispersed multi-walled carbon nanotubes (MWCNTs), and deeply reveals the mechanism of action of MWCNTs. The research results indicate that the optimal content of MWCNTs varies among the three calcium-containing systems. The ability to inhibit drying shrinkage increases with the addition of MWCNTs, and this effect is more pronounced in the high calcium-containing system. The appropriate addition of MWCNTs provides nucleation sites that promote the polymerization reaction of alkali-activated materials. When the MWCNTs content reaches 1.0 wt%, it hinders the contact area between raw materials and the alkali activator, as well as the polymerization of the gel phase chains, leading to an increase in the accumulated pore volume and a decrease in compressive strength. This study provides experimental and theoretical foundations for the application of MWCNTs in different calcium-containing systems.
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