Performance and Hydration of One-part Geopolymer Activated with NaAlO2

Geopolymer is a new type of cementitious material. Compared with ordinary Portland cement,it has many technical advantages such as green environmental protection,energy saving and low carbon,and excellent performance. At present,geopolymeris manufactured with two-parts materials including alumina-silicate materials and aqueous alkali,which leads to harsh transportation conditions,and difficult to control construction in site. Therefore,it is difficult to apply in civil engineering on a large scale. In view of this,the present work aims to study the performance regulation and hydration mechanism of NaAlO2 on one-part geopolymer. In the raw materials of geopolymer,the alkali solution was changed to a solid alkali activator,and NaAlO2 with 2% of raw material powder was employed to improve its workability. The results reveal that NaAlO2 has a fast hydrolysis rate,and it is easy to generate an Al-rich reaction environment in the early stage of the reaction,and quickly form hydrated calcium aluminosilicate,so that the one-part geopolymer can prolong the setting time without changing the compressive strength,and the microstructure also tends to gel and densify. Hence,the adding of a small amount of NaAlO2 is conducive to breaking through the technical bottleneck of the current application of two-parts geopolymer and promoting the large-scale application of geopolymer in engineering. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.