Role of Nano-Additives in Improving Mortar Resistance to Chemical Attacks: A Comparative Study on Nano-silver and Nano-silica
Authors :- S Sata, M Suthar, M Mungule, KM Vyas
Publication :- Journal of Building Engineering (Elsevier), 2026
The present study explores the use of colloidal nanosilver (cAgNPs) embedded cementitious composites to enhance resistance against sulfate and chloride attack by refining pore structure and stabilizing reaction products. The experimental investigation compares the performance of control mortar specimens with those incorporating cAgNPs. For benchmarking, commercially available nanosilica (SiNPs) is also evaluated to underscore the distinct effects of cAgNPs. Mortar specimens with binder-to-filler ratios of 1:2 and 1:1 were assessed for compressive strength and stress-strain behavior both before and after exposure to aggressive environments, including acidic (1 % H2SO4) and alkaline (5 % Na2SO4) sulfates, and chloride (5 % NaCl) solutions. Select compositions were further examined for weight change, pH variation during exposure, and microstructural alterations using TGA and FT-IR analyses. The findings reveal that cAgNPs incorporation results in minimal weight variation, reduced calcium hydroxide depletion, and limited degradation of microstructural phases such as C-S-H (Calcium Silicate Hydrate), ettringite/gypsum, and Friedel's salt. Additionally, cAgNPs-modified mortars maintained their compressive strength and stress-strain characteristics even under harsh exposure, highlighting their potential for superior durability in aggressive environments.