The present study evaluated the use of alkali-activated fly ash-based matrices containing different reactive aggregates (quartz, basalt and limestone) to mitigate the alkali-aggregate reaction (AAR). The fly ash activation was performed with sodium hydroxide (NaOH) solution, with a molar ratio (Na2O/SiO2) of 0.4. Reference matrices were prepared using Portland cement type V (ARI). All composites were prepared with a mass ratio of 1:2.25:0.47 (binder: aggregate: water/agglomerant ratio). The petrographic analyses allowed the identification of potentially reactive phases in the three studied aggregates. From the results, it was verified that the Portland cement-based matrices with basalt and quartz aggregates confirmed the reactivity of these aggregates. On the other hand, the reactivity of the same aggregates was not manifested in the CVAA-based matrices, classifying the basalt and quartz aggregates as innocuous in the alkali-activated matrix. Therefore, CVAA-based matrices mitigated AAR when using reactive basalt and quartz aggregates. However, the limestone aggregate did not show reactivity in the matrices studied.

The present study evaluated the use of red ceramic residues (RCR) as pigments in matrices based on White Portland cement. Five mortars were prepared for the present study: control mortar (M0), at 1:2,3 ratio (cement: sand) and water/cement ratio of 0.60, other four mortars were prepared containing RCR in 10% (M10), 20% (M20), 50% (M50), 100% (M100) of volume in replace to the sand. Colorimetric tests indicated a significant increase in the coloring, due to the increase of the RCR used. Tests of resistance to compression strength indicated a significant increase in the results as there was an increase in the substitution content of the sand by RCR. In the flexural tensile strength was no significant influence for contents of up to 50%. Therefore, the RCR showed potential as a pigmentation product and can contribute to the increase in compressive strength in Portland cement-based matrices.