Preparation of shrinkage-free alkali-activated slag material using MgO as both the activator and the expansive agent




Alkali-activated slag, MgO, Autogenous shrinkage, Drying shrinkage


Alkali-activated slag (AAS) materials activated by NaOH or waterglass has been long-term criticized for the developed substantial shrinkage. To this regard, this paper explored MgO as both an activator and an expansive agent to prepare shrinkage-free AAS. The setting time, mechanical strength, pore structure, autogenous shrinkage, drying shrinkage, and hydration products of MgO-activated AAS were studied. Experimental results confirmed that MgO can effectively mitigate the autogenous shrinkage and drying shrinkage of AAS via the expansive deformation caused by Mg(OH)2. Generally, AAS with a higher dosage of MgO developed less shrinkages and refiner pore structures with more gel pores. An optimal dosage of 9% MgO is recommended to prepare AAS with near zero shrinkage and the highest flexural strength.


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How to Cite

Chen, P. ., Chen, Q. ., Fang, Y. ., Wang, C. ., Wang, X. ., Li, J. ., & Wang, Y. . (2023). Preparation of shrinkage-free alkali-activated slag material using MgO as both the activator and the expansive agent. Materiales De Construcción, 73(349), e306.



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