Influence mechanism of curing temperature on geopolymerization reaction: A comprehensive review

The development of early strength in geopolymer (GP) is significantly influenced by the chosen curing method. Among these, appropriate thermal curing is crucial in enhancing the compactness of GP's microstructure and appreciably augmenting its early strength. This study examines the direct and indirect mechanisms of curing temperature's influence on ion diffusion, water and gel phase evolution, electrical conductivity, and exothermic amplitude during the geopolymerization process of GP through extensive literature research, comparative analysis, and synthesis, so as to provide support for its practical application in construction engineering. It indicates the effects of curing temperature on the mechanical properties and microstructure of GP. Before the temperature threshold, an increase in curing temperature accelerates the movement of water molecules within the system, enhancing the dissolution rate of precursor materials and augmenting the diffusion capability of conductive ions. This process fosters the formation of aluminosilicates and propels the progression of the geopolymerization reaction, facilitating the development of beneficial nanopores and effectively boosting the production of GP, and the mechanical properties of the specimens. However, when the curing temperature exceeds this threshold, excessively high temperatures cause uneven distribution of hydration products and the formation of gel phase coatings. This, in turn, hinders the further dissolution of precursor materials, decreases the formation of sol phases and diminishes the mechanical properties of the specimens. Furthermore, high temperatures accelerate water loss within the system, impeding mass transfer, increasing porosity, and causing structural damage, significantly reducing the strength and durability of GP materials. • Influence mechanism of curing temperature on geopolymerization reaction was investigated. • Appropriate thermal curing significantly enhances geopolymer's early strength and microstructural compactness. • Curing temperature impacts geopolymerization via ion diffusion, water/gel evolution, conductivity, and exothermic amplitude. • Below the threshold, high temperatures accelerate reactions but exceeding it hinders dissolution and reduces properties.