Volkanik tüf esaslı geopolimerlerin basınç dayanımına kür süresi ve sıcaklığın etkileri

Çimento klinkeri üretimi esnasında atmosfere salınan CO2 gazı sera etkisi nedeniyle küresel ısınmaya neden olmaktadır. Günümüzde bu durum çok tehlikeli boyutlara ulaşmış olup insan yaşamını tehdit eder hale gelmiştir. Bu noktada klinker içermeyen geopolimer üretimi bilim insanları tarafından etkili bir çözüm olarak sunulmaktadır. Bu çalışmada volkanik tüf esaslı geopolimerlerin Portland çimentosuna alternatif kullanım potansiyelleri araştırılmıştır. Araştırma neticesinde volkanik tüf katkılı geopolimerin zeolit içermemesine rağmen makul basınç dayanım değerlerine ulaştığı ve dolayısıyla inşaat sektöründe üretim potansiyelinin bulunduğu tespit edilmiştir. Volkanik tüf esaslı geopolimer dayanımı üzerinde esas etkili mineralin feldispat olduğu, bunun yanında kuvars mineralinin hammaddenin fiziksel özelliklerine etki dolayısıyla geopolimerleşme üzerinde pozitif etkisinin olduğu tespit edilmiştir. Ayrıca, yüksek erken basınç dayanım için yüksek sıcaklıklarda termal kür işlemi, yüksek geç basınç dayanım için ise düşük sıcaklıklarda termal kür işlemi önerilmektedir.

Anahtar Kelimeler:

Basınç dayanım, Geopolimer, Kür süresi, Sıcaklık, Volkanik tüf

Effect of curing time and temperature on compressive strength of volcanic tuff-based geopolymer

During cement clinker production, CO2 gases released into the atmosphere causes Global warming due to the greenhouse effect. Nowadays, this situation has reached very dangerous levels and threatened the human life. At this point, the production of clinker free-geopolymer is offered by scientist as an effective solution. In this study, the potential of usability of volcanic tuff-based geopolymer to the Portland cement was investigated. As a result of the research, although the volcanic tuff-based geopolymer does not contain zeolite, it has reached reasonable compressive strength values, and therefore has a production potential in the construction sector. It has been determined that the main effective mineral on the strength of volcanic tuff-based geopolymer is feldspar, besides, quartz has a positive effect on the geopolymerization due to the effect on the physical properties of the raw material. In addition, thermal curing at high temperatures is recommended for high early compressive strength achievements, and thermal curing at low temperatures is recommended for high late strength achievements.

Keywords:

Compressive strength, Geopolymer, Curing time, Temperature, Volcanic Tuff,

PDF

___

Baykara, H., Cornejo, M.H., Murillo, R., Gavilanes, A., Paredes, C. and Elsen J. (2017). Preparation, characterization and reaction kinetics of green cement: Ecuadorian natural mordenite-based geopolymers. Materials and Structures, 50, 188-200, https://doi.org/10.1617/s11527-017-1057-z.
Davidovits, J. (1994). Properties of geopolymer cements. In: First International Conference on Alkaline Cements and Concretes, Kiev, Ukraine. pp. 131-149.
Ekinci, E., Türkmen, İ., Kantarcı, F. and Karakoç, M.B. (2019). The improvement of mechanical, physical and durability characteristics of vpşcanic tuff based geoplymer concrete by using nano silica, micro silica and Styrene-Butadiene Latex additives at different ratios. Construction and Building Materials, 201, 257-267, https://doi.org/10.1016/j.conbuildmat.2018.12.204.
Fisher, R.V. and Schmincke, H.U. (1984). Pyroclastic Rocks. Springer Verlag, 472 pp.
Güngör, D. (2019). Doğal zeolit-bazlı geopolimerlerin özellikleri. Yüksek Lisans Tezi, Recep Tayyip Erdoğan Üniversitesi, Fen Bilimleri Enstitüsü, Rize.
Kohout, J. and Koutnik, P. (2020). Effect of filler type on the thermo-mechanical properties of metakaolinite-based geopolymer composites. Matreials, 13(10), 2395, https://doi.org/10.3390/ma13102395.
Nikolov, A., Nugteren, H. and 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.
Özen, S. and Alam, B. (2018). Compressive strength and microstructural characteristics of natural zeolite-based geopolymer. Periodica Polytechnica Civil Engineering, 62(1), 64-71, https://doi.org/10.3311/PPci.10848.
Shi, C., Jimenez, A.F. and Palomo, A. (2011). New cements for the 21st century: The pursuit of an alternative to Portland cement. Cement and Concrete Research, 41, 750-763, https://doi.org/10.1016/j.cemconres.2011.03.016.
Tekin, İ. (2016). Properties of NaOH activated geopolymer with marble, travertine and volcanic tuff wastes. Construction and Building Materials, 127, 607-617, https://doi.org/10.1016/j.conbuildmat.2016.10.038.
Van Deventer, J.S.J., Provis, J.L. and Duxson, P. (2012). Technical and commercial progress in the adoption of geopolymer cement. Minerals Engineering, 29, 89-104, https://doi.org/10.1016/j.mineng.2011.09.009.
Villa, C., Pecina, E.T., Torres, R. and Gomez, L. (2010). Geopolymer synthesis using alkaline activation of natural zeolite. Construction and Building Materials, 24, 2084-2090, https://doi.org/10.1016/j.conbuildmat.2010.04.052.
Xu, H. and 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.