Akademik Veri Yönetim Sistemi
15. ULUSLARARASI ARTEMİS BİLİMSEL ARAŞTIRMALAR KONGRESİ , Bucuresti, Romanya, 28 - 30 Mart 2026, ss.287-293, (Tam Metin Bildiri)
The sensitivity of compressive strength development in Class C fly ash-based geopolymers to activator chemistry and curing regime was investigated. Mixtures prepared with NaOH (8, 12, and 16 M), KOH (8, 12, and 16 M), and sodium silicate solutions with Na₂O/SiO₂ moduli of 2.00, 2.75, and 3.50 were evaluated under 7-day ambient curing, 7-day water curing, and thermal pre-curing at 70 °C for 48 h. In all mixtures, the liquid-to-solid ratio was fixed at 0.50, the total solid amount was kept at 150 g, and the activator amount was maintained at 75 g. Performance evaluation was carried out using the combined contribution indicator Δfc,comb = fc,28th – fc,7amb and the age-dependent development ratio R = fc,28th / fc,7th. The results showed that the response to thermal pre-curing varied markedly depending on activator type. While the KOH series exhibited a more stable and mostly positive contribution, negative Δfc,comb values were identified in some high-molarity mixtures of the NaOH series. The Na₂O/SiO₂ series showed a narrower and more balanced development profile. Previous studies have also reported that the reaction kinetics, curing sensitivity, and strength development of Class C fly ash systems vary together with activator composition due to their high calcium content (Chindaprasirt et al., 2007; Guo et al., 2010; Li, Ma, et al., 2013; Li, Wang, et al., 2013; Pangdaeng et al., 2014). Keywords: Geopolymer, Class C fly ash, activator chemistry, thermal pre-curing, compressive strength