Evaluation of Pozzolanic Activity of Two Different Types of C and F Fly Ashes with Fineness Factor

Today, energy produced from coal is economical compared to other sources but it faces a very serious waste problem. However, these wastes are evaluated by using them as mineral additives in cement, which leads to lower cement costs, saving resources, producing environmentally friendly cement, reducing CO۲ gas, and producing high-strength cement. In this work, the pozzolanic properties of different types of fly ash (Afşin Elbistan C type and Çayırhan F type) are investigated. The fly ashes used in the study are first subjected to the milling process (۱۰, ۲۰, ۳۰, ۴۵, and ۶۰ minutes), and then the ۲۸ and ۹۰-day pozzolanic activity index tests of the milled and unmilled ashes are performed. The results obtained show that the ۲۸-day pozzolanic activity value of the ashes subjected to ۲۰-, ۳۰-, ۴۵-, and ۶۰-minute milling times are higher than the value specified in the standard, compared to the unmilled and ۱۰ min milled fly ash. In addition, for all fly ash samples, the ۹۰-day pozzolanic activity index results show that while the pozzolanic activity index value of Çayırhan (ÇYH) fly ash is higher than the standard value, that of Afşin Elbistan (AE) fly ash is lower than standard. The outcomes of the present study show that the mechanical properties of the fly ash are generated by the burning of coal increase after milling process, and thus can be used as a mineral additive. With the effect of grinding, both fly ash increase the pozzolanic activity. The results are determined with the experimental results obtained.

Keywords:

Fly Ash , Grinding Time , Pozzolanic activity index , Fineness , Grinding