Kalsine edilmiş zeolit esaslı geopolimerlerin basınç dayanımına mineral katkı olarak cürufun etkisi

Yıl 2023, Cilt: 13 Sayı: 4, 939 - 948, 15.10.2023

Sevgi Özen

https://doi.org/10.17714/gumusfenbil.1297172

Öz

Geopolimerler, yeşil bağlayıcı malzeme olarak adlandırılan ve başlangıç hammaddeleri olarak doğal veya atık malzemeleri içeren yapı malzemeleridir. İnşaat sektöründeki potansiyel uygulamaları bilimsel olarak oldukça araştırılmış olmasına rağmen, doğal malzeme esaslı geopolimerlerin yaygın kullanımları sınırlı kalmıştır. Bunun temel nedeni, doğal malzeme esaslı geopolimerlerin düşük erken basınç dayanım değerlerine sahip olmaları ve dolayısıyla oda koşullarında erken dönemde yeterli kürleme sağlayamamalarıdır. Bu sorunu aşmak için öncelikle klinoptilolit içeren tüf 900°C’de kalsinasyon işlemine maruz bırakılmış, ardından mineral katkı olarak yüksek fırın cürufu eklenmiştir. Elde edilen geopolimerlerin mukavemet gelişimi, basınç dayanım analizleri kullanılarak saptanmıştır. Mikro yapısal incelemeler, XRD ve SEM analizleri kullanılarak gerçekleştirilmiştir. Yapılan analizler sonucunda, kalsinasyon işleminin erken dönemde mukavemeti artırdığı ve cüruf katkısıyla basınç dayanımının daha da iyileştiği belirlenmiştir. Analiz sonuçlarına göre 900°C’de kalsine edilmiş yüksek fırın cürufu katkılı geopolimerin 28 günlük basınç dayanım değeri 46 MPa olarak saptanmıştır. XRD analizi sonucunda, malzemenin kalsinasyon başarısının amorf faz ile ilişkili olduğu tespit edilmiştir. Ayrıca, SEM/EDX analizi ile geopolimer jelin en iyi cüruf katkılı geopolimerde geliştiği ortaya konulmuştur.

Anahtar Kelimeler

Cüruf, Geopolimer, Kalsinasyon, Klinoptilolit

The effect of slag as mineral admixture on the compressive strength of calcined zeolite-based geopolymer

Öz

Geopolymers, referred to as green binder materials, are construction materials that incorporate natural or waste materials. Despite extensive scientific research on their potential applications in the construction sector, widespread utilization of natural material-based geopolymers has remained limited. The primary reason for this limitation is their low early compressive strength values, which consequently hinder achieving adequate curing under ambient conditions. To overcome this challenge, the tuff containing clinoptilolite was subjected to a calcination process at 900°C, followed by the addition of blast furnace slag as a mineral admixture. The strength development of the synthesized geopolymers was compared through compressive strength analyses. Microstructural examinations were conducted using XRD and SEM analyses. The analysis results demonstrated that the calcination process enhanced the early strength development, and the addition of slag further improved the compressive strength. Asa result of XRD analysis it has been determined that the success of material calcination is associated with the amorphous phase. According to the analysis results, the compressive strength of the high blast furnace slag blended geopolymer, calcinated at 900°C, was determined as 46 MPa after 28 days. Moreover, the SEM/EDX analysis revealed that the geopolimer gel exhibited the best performance in the presence of slag additives.

Anahtar Kelimeler

Slag, Geopolymer, Calcination, Clinoptilolite

Kaynakça

• Almutairi, A.L., Tayeh, B.A., Adesina, A., Isleem, H.F., & Zeyad, A.M. (2021). Potential applications of geopolymer concrete in construction: A review. Case Studies in Construction Materials, 15, e00733. https://doi.org/10.1016/j.cscm.2021.e00733.
• ASTM C39 / C39M-18 (2018). Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens, ASTM International, West Conshohocken, PA. https:// doi.org/10.1520/C0039_C0039M-18.
• Bao Y., Grutzeck M.W., & Jantzen C.M. (2005). Preparation and properties of Hydroceramic Waste Forms made with simulated Hanford low-activity waste. Journal of the American Ceramic Society, 88, 3287-3302. https://doi.org/10.1111/j.1551-2916.2005.00775.x.
• Bondar, D., Lynsdale, C.J., Milestone, N.B., Hassani, N., & Ramezanianpour, A.A. (2011). Effect of heat treatment on reactivity-strength of alkali-activated natural pozzolan. Construction and Building Materials, 25, 4065-4071. https://doi.org/10.1016/j.conbuildmat.2011.04.044.
• Davidovits, J. (1994). Properties of geopolymer cements. In First international conference on alkaline cements and concretes, Scientific Research Institute on Binders and Materials, Kiev State, Technical University, Kiev, Ukraine.
• Fernandez-Jimenez, A., Palomo, A., & Criado, M. (2006). Alkali activated fly ash binders. A comparative study between sodium and potassium activators. Materiales de Construccion, 56(281), 51–65. https://doi.org/10.3989/mc.2006.v56.i281.92.
• Glukhovsky, V. (1967) Budivelnik Publish, Kiev.
• Krivenko, J., Skurchinskaya, L., Lavrinenko, O., Starkov, E., & Konalov, E. (1994). Physico-chemical bases of radioactive wastes immobilization in a mineral-like solidified stone, in: P.V. Krivenko (Ed.), Alkaline Cements and Concretes, Proceedings of the 1st International Conference, VIPOL Stock Co., Kiev, Ukraine, pp. 1095–1106. Luukkonen, T., Abdollahnejad, Z., Yliniemi, J., Kinnunen, P., &Illikainen, M. (2018). One-part alkali-activated materials: A review. Cement and Concrete Research, 103, 21-34. https://doi.org/10.1016/j.cemconres.2017.10.001.
• Moon, J., Bae, S., Celik, K., Yoon, S., Kim, K.H., Kim, K.S., & Monteiro, P.J.M. (2014). Characterization of natural pozzolan-based geopolymeric binders. Cement and Concrete Composites, 53, 97-104. https://doi.org/10.1016/j.cemconcomp.2014.06.010.
• Nikolov, A., Rostovsky, I., & Nugteren, H. (2017). Geopolymer materials based on naturla zeolite. Case Studies in Construction Materials, 6, 198-205. https://doi.org/10.1016/j.cscm.2017.03.001.
• Nadoushan, M.J. & Ramezanianpour, A.A. (2016). The effect of type and concentration of activators on flowability and compressive strength of natural pozzolan and slag-based geopolymers. Construction and Building Materials, 111, 337-347. https://doi.org/10.1016/j.conbuildmat.2016.02.086.
• Nikolov, A., Nugteren, H., & Rostovsky, I. (2020). Optimization of geopolymers based on natural zeolite clinoptilolite by calcination and use of aluminate activators. Construction and Building Materials, 243, 118257. https://doi.org/10.1016/j.conbuildmat.2020.118257.
• Xu, H. & van Deventer, J.S.J. (2000). The geopolymerisation of alumino-silicate minerals. International Journal of Mineral Processing. 59, 247-266. https://doi.org/10.1016/S0301-7516(99)00074-5.
• Xu, H. & van Deventer, J.S.J. (2002). Factors affecting the geopolymerization of alkali-feldspars. Minerals and Metallurgical Exploration, 19, 209- 214. https://doi.org/10.1007/BF03403271.