Influence of Early Oven Curing on the Alkali Activated Binders with Reactive Magnesia Replacement


Magnesia is widely used an expansive agent in construction materials due to its delayed hydration, which will compensate for the thermal shrinkage. This study investigates the influence of magnesia and early oven curing on the mechanical performance and microstructures of alkali-activated natural clay samples under different curing regimes after 28 days. Microstructural analysis and pH measurements were conducted to assess the strength of the samples. Results indicate that the strength was greatly improved (in comparison with the control samples) by the incorporation of magnesia due to the formation of nesquehonite. Meanwhile, oven curing is an effective method in the fast strength development in alkali-activated natural clay. The results also demonstrated the possibility of CO2 curing in the strength development of the magnesia-modified alkali-activated natural clay.

Keywords: magnesia, natural clay, oven curing, compressive strength, microstructure

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