Mechanical and durability properties of alkali-activated composites: a review and statistical inference on critical parameters
摘要
The activation of aluminosilicate precursor material involves a complex chemical process, from dissolution through polymerization to the finished product of the alkali-activated composite (AAC). Furthermore, the standardization and optimization of this innovative material need to be appropriately well documented, especially with the lack of a standard mix design code, if it is to replace cement binders in the construction material industry. More gaps in the mix design methods and their impact on AAC properties need to be addressed. Moreover, the important findings made so far need to be reviewed to encourage further research and promote its practical application. This paper offers a thorough review to explore and develop a database for understanding several factors influencing the mechanical (compressive and flexural strength) and durability properties (sulfate, sea water, and high-temperature resistance, as well as chloride permeability and freezing and thawing resistance) of AAC. In addition, this study provides insights and inferences on variables influencing the compressive strength of AAC mixes exposed to elevated temperature using normalization residuals and linear regression models. It was found that the developed linear regression model effectively describes the effects of temperature on AAC, regardless of the variable makeup of the mixes. The regression results indicate that changes in variables such as fiber content, fiber length, and the ratio of Na2O in Na2SiO3 activators show a similar reduction in strength, particularly at 400 °C, with coefficients of determination ranging from 0.80 to 0.97. Therefore, the outcome of this review will promote a clear understanding of the parameters required to produce durable and eco-friendly composites.