## 4 Conclusions  
This research was focused on investigating the performance of a novel material called reactive powder geopolymer concrete (RPGC). Class-F (low calcium) FA was used as the source material, which effectively eliminated the need to use ordinary Portland cement in the mix design. The RPGC formulations were a combination of the geopolymer (GP) paste and reactive powder concrete (RPC) mix designs, selected through a series of trial tests. Even though several studies have been reported on the performance of GPs and RPCs, the available literature on the mechanical properties and, most importantly, the fire performance of the combination of these two materials are scarce. The key finding from the present study can be summarized as follows:  
* Generally, the RPC samples that were investigated in the present study produced low workability conditions as compared to the GP and RPGC samples.
* The RPGC specimens, on the other hand, displayed higher workability conditions. This can be due to the relatively smaller particle sizes of the FA used for the casting of RPGC samples, as compared to the cement in RPC ones.
* The slump flow values of the RPGC specimens were somewhat lower when compared to the corresponding values of the GP mixtures. This can be attributed to the inclusion of aggregate particles in the RPGC formulations. The RPC specimens that were conditioned at 75 \({}^{\circ}\)C recorded higher compressive strengths compared to those conditioned at the ambient temperature. This can be assumed to arise from the formation of relatively denser microstructures, thus leading to a better cohesive bonding state.
* Furthermore, the RPC specimens were found to undergo explosive spalling, at an elevated temperature (ca. 360 \({}^{\circ}\)C), presumably owing to the built up of increased vapor pressure and higher thermal gradients.
* Unlike the RPC specimens, no explosive spalling conditions were apparent in the RPGC specimens, with no thermal cracking at 400 \({}^{\circ}\)C and only one of the specimens  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Mass Loss (wt. \%) from TGA**} & \multicolumn{2}{c}{**Mass Loss (wt. \%) from Weighing**} \\
**Sample ID** & **400 \({}^{\circ}\)C** & **800 \({}^{\circ}\)C** & **400 \({}^{\circ}\)C** & **800 \({}^{\circ}\)C** \\ \hline RPGC 01 & 3.06 & 3.97 & 6.750 & 5.600 \\ RPGC 02 & 3.75 & 4.81 & 8.060 & 8.070 \\ RPGC 03 & 5.00 & 5.86 & 9.000 & 9.030 \\ RPGC 04 & 5.95 & 6.64 & 11.23 & 11.32 \\ Minimum & 3.06 & 3.97 & 6.750 & 5.600 \\ Maximum & 5.95 & 6.64 & 11.23 & 11.32 \\ Average & 4.44 & 5.32 & 8.760 & 8.510 \\ \hline \hline \end{tabular}
\end{table}
Table 15: Percentage mass loss (TGA and Balance results)–RPGC.  
undergoing mild thermal cracking even at 800 \({}^{\circ}\)C. This can be due to the higher levels of silicon in the FA compared to OPC.
* The RPGC specimens generally recorded lower percentage losses in mass compared to the GP specimens, which could be due to the reduced water loading in them.  
Conceptualization, M.G., S.F. and P.J.; methodology, M.G. and T.K.; validation, M.G., S.F., P.J. and T.K.; formal analysis, T.K.; investigation, M.G., S.F., P.J. and T.K.; resources, M.G.; data curation, M.G., S.F., P.J. and T.K.; writing--original draft preparation, M.G., P.J. and T.K.; writing--review and editing, P.J.; supervision, M.G., S.F. and P.J.; project administration, M.G., S.F. and P.J.; funding acquisition, M.G. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
Data Availability Statement: Data is contained within the current article.  
The authors are grateful for the technical support provided by [PERSON] and [PERSON], Institute for Sustainable Industries and Liveable Cities.  
The authors declare no conflict of interest.