## 3 Results and Discussion
The concretes were cooled either in air to prevent changes in internal stress due to temperature from affecting the compressive strength. Figure 20 displays the compressive strength of the specimens after the high-temperature test.. \begin{table}
\begin{tabular}{c c c c} \hline  & **2\% CFGC** & **5\% CFGC** & **10\% CFGC** \\ \hline
**Element** & **Atom (\%)** & **Atom (\%)** & **Atom (\%)** \\ \hline
**C** & 21.45 & 15.26 & 17.14 \\ \hline
**O** & 59.83 & 58.07 & 61.65 \\ \hline
**Na** & 0.69 & 2.00 & 3.19 \\ \hline
**Ca** & 15.72 & 16.00 & 9.22 \\ \hline
**Mg** & 0.57 & 1.18 & 1.20 \\ \hline
**Si** & 1.36 & 5.97 & 5.98 \\ \hline
**Al** & 0.34 & 1.52 & 1.48 \\ \hline \end{tabular}
\end{table} 
Table 10: Atomic distribution of 2%, 5%, and 10% CFGC specimens (% by weight). Figure 19: EDS image of 10% CFGC. According to Figure 20, it can be observed that all the concretes in the study maintained their compressive strength up to 100 \({}^{\circ}\)C. Additionally, the geopolymer concrete specimens experienced a thermal cure, resulting in strength increases of 29-59%. On the other hand, PCC specimens only showed a slight increase of approximately 4% up to 100 \({}^{\circ}\)C, after which they began to lose strength. Although the geopolymer specimens experienced a reduction in strength, they remained stronger than both their room temperature strength and the strength of the PCC specimen up to 600 \({}^{\circ}\)C. As per the literature, it has been reported that geopolymer concretes can maintain their compressive strength up to 600 \({}^{\circ}\)C [37]. The compressive strength of the fiber-reinforced geopolymer concrete specimens remained largely intact up to 300 \({}^{\circ}\)C, in contrast to the PCC specimens. At 900 \({}^{\circ}\)C, the maximum compressive strength of the PCC and fiberless geopolymer specimens was 11.3 and 9.3 MPa, respectively. However, the compressive strength of the 5% and 10% fiber specimens remained intact up to 24.4 and 19.7 MPa, respectively. Considering that all other parameters are the same, it could be concluded that this difference is due to the presence of ceramic fiber. Figures 21-24 show images of the specimens before and after the high-temperature test at 600 and 900 \({}^{\circ}\)C.  
The specimens tested at the high temperature of 600 \({}^{\circ}\)C experienced a compressive strength decrease of 45.06% for PCC, 32.79% for 0% CFGC, 25.25% for 2% CFGC, 18.46% for 5% CFGC, and 13.19% for 10% CFGC compared to their room temperature strength. At 900 \({}^{\circ}\)C, the specimens lost compressive strength at a rate of 76.75% for PCC, 81.06% for 0% CFGC, 64.36% for 2% CFGC, 49.38% for 5% CFGC, and 58.09% for 10% CFGC, compared to their room temperature compressive strength. Figure 21: View of the PCC and 5% fiber sample before testing at 600 \({}^{\circ}\)C.  
Figure 20: Compressive strength of geopolymer concrete after high-temperature test (MPa). Figure 24: View of the PCC and 10% fiber sample after testing at 900 \({}^{\circ}\)C.  
Figure 23: View of the PCC and 10% fiber sample before testing at 900 \({}^{\circ}\)C.  
Figure 22: View of the PCC and 5% fiber sample after testing at 600 \({}^{\circ}\)C.