## 2 Material and Method
### Material  
Within the scope of this study, slag (Oyak Cimento, Mersin, Turkiye), silica fume (ETI elektrometakurji A.S., Antalya, Turkiye), fly ash (Cenal Elektrik A.S. Canakkale, Turkiye), ceramic fiber (RBS Ravago A.S., Kayseri, Turkiye), superplasticizer (Polisan, Izmir, Turkiye), Na\({}_{2}\)SiO\({}_{3}\)-NaOH (EMA Grup A.S, Izmir, Turkey), fine aggregate and coarse aggregate (Dermin Beton Ltd.Sti,Tunceli, Tukiye) were used when manufacturing geopolymer concrete. The chemical analysis results of ground slag, fly ash, and silica fume are given in Table 2.  
The chemical composition and particle sizes of slag, fly ash, and silica fume are given by the manufacturer. Slag and fly ash have particle sizes below 100 \(\upmu\)m, while silica fume has particle sizes below 25 \(\upmu\)m.  
The chemical analysis results of alkaline liquids NaOH and Na\({}_{2}\)SiO\({}_{3}\) are in Tables 3 and 4. Ceramic fiber is a material with high thermal resistance. For this reason, it is used in molten form in metal casting sprues. In this way, the thermal resistance of the sprues increases and can withstand high temperatures. This study aims to explore the potential of utilizing ceramic fiber, a material known for its high thermal resistance and commonly used in metal casting runners, to enhance the thermal resistance of geopolymer concretes. The objective is to investigate the feasibility of this method in enabling geopolymer concretes to withstand high temperatures. Ceramic fiber, which increases the thermal resistance in casting runners, is expected to have a similar effect in geopolymer concrete. The results of ceramic fiber's physical and chemical analysis are given in Tables 5 and 6. This study examined the dissolution performance of ceramic fiber in various liquids, namely NaOH, Na\({}_{2}\)SiO\({}_{3}\), water, and superplasticizer, over 24 h in a laboratory environment. The results indicated that the ceramic fiber dispersed uniformly in superplasticizer and NaOH, demonstrating superior dissolution performance compared to water and Na\({}_{2}\)SiO\({}_{3}\). During the casting of geopolymer concrete, the fiber was dissolved with the aid of activators and water before being added to the solid mix. It has been determined through SEM and EDS scans that the ceramic fiber was evenly distributed throughout the internal structure of the geopolymer concrete. Figures 2-5 show the dissolution state of the ceramic fiber after being kept in different liquids for 24 h. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{1}{c}{**Na\({}_{2}\)CO\({}_{3}\) (\(\leq\))**} & \multicolumn{1}{c}{**Na\({}_{2}\)SO\({}_{4}\)**} & \multicolumn{1}{c}{**Na\({}_{2}\)CO\({}_{3}\)**} & \multicolumn{1}{c}{**Cl**} & \multicolumn{1}{c}{**SO\({}_{4}\)**} & \multicolumn{1}{c}{**Fe**} \\  & (\(\leq\)) & (\(\leq\)) & (\(\leq\)) & (\(\leq\)) & (\(\leq\)) \\ \hline
0.5 & 0.008 & 0.008 & 0.005 & 0.005 & 0.001 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Chemical analysis of Na\({}_{2}\)SiO\({}_{3}\). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Oxides** & **Slag** & **Fly Ash** & **Silica Fume** \\ \hline SiO\({}_{2}\) & 39.14 & 59.37 & 70–80 \\ \hline Al\({}_{2}\)O\({}_{3}\) & 13.30 & 21.40 & 2.55–4.10 \\ \hline Fe\({}_{2}\)O\({}_{3}\) & 1.50 & 8.62 & 1.17–5.00 \\ \hline CaO & 33.00 & 3.24 & 1.06–1.80 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Chemical analysis results of ground slag, fly ash, and silica fume (% by weight). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Na\({}_{2}\)CO\({}_{3}\) (\(\leq\))** & **Na\({}_{2}\)SO\({}_{4}\)** & **NaClO\({}_{3}\)** & **Cl** & **SO\({}_{4}\)** & **Fe** \\  & (\(\leq\)) & (\(\leq\)) & (\(\leq\)) & (\(\leq\)) & (\(\leq\)) \\ \hline
0.5 & 0.008 & 0.008 & 0.005 & 0.005 & 0.001 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Chemical analysis of NaOH (% by weight).