The authors conclude that “durability of AAMs is strongly dependent on the nano- and microstructure of the reaction products forming in these systems, as a function of the type of precursor, the nature and concentration of the activator, and also the maturity of the material. High-Ca systems have a structure mainly dominated by a C–A–S–H gel, which is less porous than the ‘geopolymer’ gel forming in low-Ca systems. This is one of the main factors controlling the transport properties of AAMs; however, the differences in chemistry of both pore solution and reaction products in AAMs produced with different precursors modify the chemical mechanisms that can lead to the decay of these binders when exposed to aggressive environments.”

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