Bülent YILMAZ, Ali UÇAR, Yılmaz KOÇAK, Atila DORUM

Uçucu kül katkılı çimento hidratasyonuna elektrokinetik özelliklerin etkisi

Bu çalışmada, referans (PÇ) ve uçucu kül katkılı çimentonun (UKKÇ) yüzey etkileşim mekanizmalarıaraştırılmıştır. PÇ, uçucu kül (UK) ve UKKÇ’nin fiziksel, kimyasal, mineralojik ve mekanik özelliklerinin yanısıra UK-PÇ tanelerinin elektrokinetik potansiyelleri (zeta potansiyel) belirlenmiştir. PÇ ve UK ile hazırlanançimento pastaları 2, 7 ve 28 gün küre tabi tutulmuştur. Bu pastaların, hidratasyon sırasında mineralojik yapısınıve faz gelişimini belirlemek için termal analiz (DTA ve TG), X-ışınları difraksiyonu (XRD) ve fouriertransformlu kızılötesi spektroskopisi (FT-IR) analizleri yapılmıştır. Ayrıca 28 günlük mikro yapıları taramalıelektron mikroskop (SEM) ile belirlenmiş ve harç numuneleri, dayanım testleri yapılarak incelenmiştir. UK; suihtiyacını ve priz süresini arttırırken, hidratasyon süresince açığa çıkan portlandit (Ca(OH)2) miktarınıazaltmıştır. Ayrıca UK, PÇ’ye göre farklı elektrokinetik davranışlar ve yüzey özellikleri göstermiştir. Bufarklılıklar harç örneklerinin dayanımlarını etkilemiştir.

The effect of electrokinetic spesification features to hydration development in fly ash blended cement

In this study, surface interaction mechanisms of the reference (OPC) and fly ash blended cements (FAC) wereinvestigated. The physical, chemical, mineralogical and mechanical properties of OPC, fly ash (FA) and FAC, aswell as the electrokinetic potentials (zeta potential) of FA-OPC particles were examined. After cement pasteswere prepared with OPC and FA, they were water-cured for 2, 7 and 28 days. The pastes were made using X-raydiffraction (XRD), differential thermal analysis (DTA) and Fourier transform infrared spectroscopy (FT-IR) inorder to determine their mineralogical composition and the determination of the phases developed during thehydration. Furthermore by scanning electron microscope (SEM) 28 days microstructures of pastes weredetermined and mortars were examined following strength tests. While the addition of FA has increased thesetting time and the amount of water demand, amount of portlandit (Ca (OH)2) decreased during the hydration.Moreover FA has shown different electrokinetic behaviors and surface features compared to OPC. Thesevariations effected on compressive strength of mortar samples.

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