INVESTIGATION OF THE EFFECTS OF CLASS C FLY ASH CEMENT SUBSTITUTION ON STRENGTH IN CEMENTED PASTE BACKFILL

Öz

Cemented Paste Backfill (CPB) Method is an important tailings management system that can provide support against collapses due to the roof loads, as well as enabling storage possibilities of high amount of process tailings at the underground. Therefore, it gains important that the paste material created in this system gets the maximum strength value depending on the time. For this purpose, the optimum mixing ratios of the paste material should be determined with minimum costs. The main purpose of this study is to determine the additive rate that it can substitute for cement in order to reduce the amount of cement, which constitutes one of the high costs of paste backfill. Firstly, the solid content of the paste material was determined as 80% according to the slump tests, and then CPB reference samples were prepared. By taking the solid content of 80% fixed, 3-11% cement was used, it was determined that the strength of the samples containing 9% and 11% cement gave sufficient strength values. Subsequently, 20-30-40 and 50% of these cement ratios were substituted with fly ash samples and their effects on the strength of CPB were examined over the curing times of 28, 56 and 90 days. As a result, it put forth that, according to reference samples, fly ash substitution of up to 30% can use in the paste mixtures with 9% cement ratio, especially in curing periods of 56 and 90 days. In addition, up to 50% fly ash substitution can use instead of cement in 11% cement.

Anahtar Kelimeler

• Pb-Zn Tailings
• Cemented Paste Backfill (CPB)
• Fly Ash
• Strength

ÇİMENTOLU MACUN DOLGUDA C SINIFI UÇUCU KÜLÜN ÇİMENTO YERİNE İKAMESİNİN DAYANIMA OLAN ETKİLERİNİN İNCELENMESİ

Öz

Çimentolu macun dolgu (ÇMD) yöntemi, öncelikle yüksek miktarda proses atıklarının yeraltında depolanabilmesine imkan vermesinin yanında tavan yüklerine bağlı göçüklere karşı da destek sağlayan önemli bir atık yönetimi sistemidir. Dolayısıyla bu sistem içerisinde oluşturulan macun malzemenin zamana bağlı olarak alacağı maksimum dayanım değeri önem kazanmaktadır. İstenilen dayanımın sağlanabilmesi için, macun malzemenin optimum karışım oranlarının en az maliyetle belirlenmesi gerekmektedir. Bu kapsamda, macun dolgudaki yüksek maliyetlerden birini oluşturan çimento miktarını düşürmek için Tufanbeyli uçucu külünün çimento yerine ikame edilebileceği yaklaşık katkı oranının belirlenmesi amaçlanmıştır. Öncelikle çökme deneylerine göre macun malzemedeki katı içeriği %80 olarak belirlenmiş ve buna göre ÇMD referans numuneleri hazırlanmıştır. %80 katı içeriği sabit tutularak %3-11 arası çimento kullanımı gerçekleştirilmiş, bunlardan %9 ve %11 çimento içerikli numunelerin dayanımlarının yeterli dayanım değerleri verdiği tespit edilmiştir. Daha sonra bu çimento oranlarının da %20-30-40 ve 50’si oranında çimento yerine uçucu kül ikameli numuneler hazırlanmış ve 28, 56 ve 90 günlük kür sürelerine göre de macun dolgu malzemesinin dayanımına etkileri incelenmiştir. Sonuç olarak, referans numunelere göre %9 çimentonun %30’una kadar uçucu kül ikamesinin özellikle 56 ve 90 günlük kür sürelerinde ve %11 çimentonun %50’sine kadar uçucu kül ikameli karışımların ÇMD karışımında kullanılabileceği ortaya konulmuştur.

Anahtar Kelimeler

• Pb-Zn Atıkları
• Çimentolu Macun Dolgu (ÇMD)
• Uçucu Kül
• Dayanım

Kaynakça

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