Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ1Optimization, high-temperature resistance, and sulfate durability of basalt powder–blended alkali-activated slag mortars
Arslan, Furkan; Dener, Murat; Karataş, Mehmet; Benli, Ahmet
This study investigates the feasibility of using basalt powder (BP), an industrial by-product with limited reactivity, as a partial substitute for granulated blast furnace slag (GBFS) in alkali-activated systems. A comprehensive experimental program was conducted in two stages: first, a systematic optimization was performed by varying mixture parameters, including BP content, alkali dosage, activator modulus, and curing temperature to evaluate compressive strength development; second, selected binder compositions were used to produce self-compacting mortars, which were further examined for flexural strength, high-temperature resistance, and sulfate durability. The results demonstrated that moderate substitution levels (up to 20–30 % BP) could achieve satisfactory compressive strength, particularly under elevated curing temperature (60 °C) with 8 % Na2O and low to moderate modulus values. At 300 °C, mixtures with 20 % BP exhibited strength enhancement due to additional geopolymerization, demonstrating superior thermal stability compared to the control. Crucially, the incorporation of BP enhanced sulfate resistance, with the 40 % BP mixture exhibiting a slight increase in compressive strength after long-term exposure, in contrast to the marked deterioration of the GBFS-only system. Consequently, this study demonstrates that BP can be effectively utilized as a sustainable binder component, offering a practical solution for waste management while enhancing the durability of alkali-activated mortars against aggressive conditions.
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İncele - MakaleAçık Erişim2026Scopus SJRQ1Sustainable hybrid activation: Synergistic effects and optimization of one-part alkali-activated slag using sodium sulfate and sodium carbonate
Orhan, Taha Yusuf; Balun, Bilal; Dener, Murat; Karataş, Mehmet
The development of one-part alkali-activated materials (AAMs) using near-neutral and moderately alkaline salts offers a promising, low-carbon alternative to hazardous two-part systems. However, overcoming delayed reaction kinetics and setting anomalies remains a critical challenge. This study systematically investigates the fresh state, mechanical, and microstructural evolution of one-part slag mortars activated by sodium sulfate (Na2SO4), sodium carbonate (Na2CO3), and their hybrid combinations, adopting a hybrid binder approach through modification with calcium-rich additives (Portland cement, hydrated lime, and quicklime). Results demonstrate that while Portland cement ensures a controlled dissolution rate and balanced setting times across all environments, the incorporation of 7.5% quicklime in pure carbonate media triggers an instantaneous flash set. This extreme reactivity leads to a severe structural collapse, plunging the 90-day compressive strength to 16.11 MPa. Microstructural analyses (TGA and FTIR) suggest a link between this mechanical failure and a massive accumulation of unreacted portlandite (4.51% mass loss) rather than cohesive C-(A)-S-H gel formation, a degradation further corroborated by a drastic attenuation in ultrasonic pulse velocity (UPV). Conversely, the synergistic implementation of hybrid sulfate-carbonate activators effectively mitigates these anomalies. Sulfate ions buffer early-age kinetics to prevent flash setting-recovering the collapsed strength up to 29.16 MPa while carbonate ions facilitate sustained late-age matrix densification. Ultimately, tailoring specific calcium boosters within a hybrid activator framework presents a highly robust and potentially low-carbon framework for developing sustainable binders for practical on-site construction applications.
AtıfScopus3WoS2OpenAlex2İncele - MakaleYalnız künye2026Scopus SJRQ1Mechanical and durability properties of sustainable alkali-activated mortars with ceramic insulator waste and andesite powder as partial substitutes for GBFS
Cemalgil, Selim; Yön, Merve Şahin; Dener, Murat; Karataş, Mehmet
This study explores the use of andesite powder (AP) and ceramic waste powder (CWP), derived from discarded electrical insulators, as supplementary precursors to ground granulated blast furnace slag (GBFS) in alkali-activated self-compacting mortars. The originality of the work lies in the combined utilization of these regionally sourced aluminosilicate wastes in binary and ternary binder systems, aiming to reduce GBFS dependency while ensuring adequate mechanical and durability performance. AP and CWP were used to replace GBFS at up to 50%, and the mixtures were evaluated for flowability, mechanical strength, density, porosity, water absorption, and capillary sorptivity. Durability was assessed through freeze–thaw cycling and high temperature exposure, and microstructural characteristics were examined using scanning electron microscope analysis. Results showed that while partial substitution with AP or CWP reduced compressive strength compared to the GBFS control, the incorporation of CWP in ternary systems partially compensated for the strength losses associated with AP. High temperature resistance improved markedly with increased CWP content; at 900°C, the 50% CWP mixture retained 44% of its original compressive strength, in contrast to 8% for the control. Although all mixtures containing waste exhibited reduced freeze–thaw resistance, mortars containing CWP exhibited superior performance compared to those with only AP. These findings highlight the potential of CWP, particularly in ternary systems, for developing sustainable alkali-activated mortars.
AtıfScopus16WoS14OpenAlex12İncele - MakaleAçık Erişim2025Scopus SJRQ1Evaluating the high-temperature resistance of self-compacting mortar incorporating waste andesite powder as a mineral admixture
Karataş, Mehmet; Bozcan, Emre; Dener, Murat
Significant amounts of waste material are generated at various stages of andesite stone processing, including mining, cutting, and polishing. Despite this, limited research has been conducted on the potential use of waste andesite powder (WAP) as a mineral admixture. The impact of WAP on the high-temperature resistance of cement-based composites remains largely unexplored. This study aims to evaluate the benefits of incorporating WAP as a partial substitute for Portland cement. Self-compacting mortars (SCMs) with varying WAP replacement rates (5%–30%) were produced and subjected to temperatures of 300°C, 600°C, and 900°C. Additionally, ternary mixtures of WAP and silica fume were produced for comparative analysis. The results showed that SCMs containing up to 10% WAP exhibited higher 90-day compressive strength compared to the control sample. Furthermore, WAP inclusion improved high-temperature resistance, and the use of WAP at higher replacement rates was feasible when combined with mineral admixtures possessing high pozzolanic activity, such as silica fume.
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