The Effect of Different Types of Boron Minerals on the Mechanical and Microstructural Properties of Geopolymer Based Mortars

Yıl 2022, Cilt: 10 Sayı: 1, 162 - 174, 01.03.2022

Oğuzhan Öztürk

https://doi.org/10.36306/konjes.1039416

Öz

Geopolymer-based materials produced by activating industrial by-products such as fly ash, slag, and metakaolin with alkali activators have engineering properties that compete with Portland cement (PC)-based composites. However, it is necessary to diversify the raw material sources with different industrial by-products to be used more widely compared to the current PC production volumes. In this sense, the evaluation of calcium (Ca)-based colemanite, sodium (Na)-based tincal and both calcium and sodium-based ulexite in cement-free geopolymer mixtures may make these types of boron minerals more valuable than their use in PC-based composites. In this study, research on the mechanical properties and microstructure effects of colemanite, ulexite and tincal-based boron minerals as binders in the production of geopolymers has been studied. In the results, it was observed that the tincal substitution was comparable to the reference mixtures containing 100% slag, although colemanite and ulexite reduced the mechanical properties. Research findings show that tincal is more suitable for use as a substitute than colemanite and ulexite. However, it is thought that boroaluminosilicates should be handled more comprehensively by testing tincal as an alkali activator as well as its substitution as a binder.

Anahtar Kelimeler

Geopolymer, Boron, Mechanical properties, Micro structure

FARKLI TÜR BOR MİNERALLERİNİN JEOPOLİMER ESASLI HARÇLARIN MEKANİK VE MİKRO YAPI ÖZELLİKLERİNE ETKİSİ

Öz

Uçucu kül, cüruf, metakaolin gibi endüstriyel yan ürünlerin alkali aktivatörlerle aktive edilmesiyle üretilen jeopolimer esaslı malzemeler, Portland çimentosu (PÇ) esaslı kompozitlerle rekabet eden mühendislik özelliklerine sahiptir. Ancak, hali hazırda PÇ üretim hacimleriyle karşılaştırıldığında, daha yaygın olarak kullanılması için farklı endüstriyel yan ürünlerle hammadde kaynaklarını çeşitlendirmek gerekmektedir. Bu anlamda, kalsiyum (Ca) tabanlı kolemanit, sodyum (Na) tabanlı tinkal ve hem kalsiyum hem de sodyum tabanlı üleksitin çimento içermeyen jeopolimerli karışımlarda değerlendirilmesi, bu tür bor minerallerini PÇ esaslı kompozitlerdeki kullanımına kıyasla daha değerli kılabilir. Bu çalışmada, kolemanit, üleksit ve tinkal esaslı bor minerallerinin bağlayıcı olarak jeopolimer üretiminde kullanılmasının mekanik özelliklere ve mikro yapı etkilerine dair araştırma ortaya konmuştur. Elde edilen sonuçlarda kolemanit ve üleksitin mekanik özellikleri kötüleştirmesine rağmen, tinkal ikamesinin %100 cüruf içeren referans karışımları ile kıyaslanabilir olduğu görülmüştür. Araştırma bulguları, kolemanit ve üleksitten ziyade, tinkalin ikame olarak kullanıma daha uygun olduğunu göstermektedir. Ancak tinkalin bağlayıcı olarak ikamesinin yanında, alkali aktivatör olarak parametrik şekilde sınanarak boroaluminosilikatların daha kapsamlı olarak ayırt edilmesi gerektiği düşünülmektedir.

Anahtar Kelimeler

Jeopolimer, Bor, Mekanik özellikler, Mikro yapı

Kaynakça

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