Acid attack on alkali-activated mortars: A test proposal

The durability of new binders in construction is one of the keys for further applications. The acid attack resistance of alkali-activated mortars (AAMs) was tested. A test proposal was developed, and the selected AAMs (precursors: blastfurnace slag, vitreous calcium silicoaluminate, fly ash and spent FCC catalyst) were analyzed in terms of acid neutralization capacity (ANC), mass loss at a constant pH= 2, and mass loss of the cubes immersed in 1 molar nitric acid solution. The results were compared to the mortars prepared with ordinary Portland cement. The ANC values were generally higher when the calcium content of the binder increased. The attacked mortars were characterized by thermogravimetry and microscopy techniques. The proposed test, based on three complementary experiments, allows the analysis of AAMs ' stability and the identification of more resistant systems to acid attack.