## 5 Conclusions  
This study experimentally investigated the deformability characteristics of bisphenol A-type epoxy-based polymer concrete by hardener type and filler, including the modulus of elasticity, setting  
Figure 11: Coefficients of thermal expansion by hardener and filler type.  
Figure 10: Variations in thermal strain by hardener and filler type: (a) AAMT hardener and (b) CAMT hardener.  
shrinkage, and thermal expansion. The primary objective of this research was to obtain basic data associated with the compatibility and dimensional stability required to apply EP polymer concrete when repairing damage to concrete structures and producing precast products.  
According to these test results, the modulus of elasticity ranged from \(25.2\times 10^{3}\) to \(27.2\times 10^{3}\) MPa when AAMT hardener was employed, and from \(24.7\times 10^{3}\) to \(27.1\times 10^{3}\) MPa when CAMT hardener was used. By filler type, these cases followed the following order: SF, GCC, BFS, and FA. However, there were no significant differences in the modulus of elasticity by type of hardener and filler. The elastic moduli of these EP polymer concretes were significantly lower than the elastic modulus of Portland cement concrete. These low moduli of elasticity are not disadvantageous in terms of compatibility with Portland cement concrete.  
The setting shrinkage ranged from \(1246\times 10^{-6}\) to \(1497\times 10^{-6}\) for AAMT hardener and from \(403\times 10^{-6}\) to \(547\times 10^{-6}\) for CAMT hardener. From this result, it was determined that there was a significant difference in setting shrinkage when different types of hardener were employed. By filler type, the order from highest to lowest setting shrinkage was: SF, GCC, BFS, and FA; the difference between each setting shrinkage was not significant. For the two hardeners employed in this study, it was determined that the low setting shrinkage obtained using the CAMT hardener was more advantageous in terms of compatibility.  
The test results by type of hardener indicate that the coefficient of thermal expansion ranged from \(18.2\times 10^{-6}\) to \(22.1\times 10^{-6}\) per \({}^{\circ}\)C for the AAMT hardener and from \(24.3\times 10^{-6}\) to \(27.4\times 10^{-6}\) per \({}^{\circ}\)C for the CAMT hardener. In terms of filler type, the order from highest to lowest coefficient of thermal expansion was: SF, GCC, BFS, and FA. In this study, the coefficient of thermal expansion of the EP polymer concrete was twice as high as that of ordinary Portland cement concrete. The cause of this result may be the high temperature generated by polymerization in epoxy resin polymer concrete.  
Generally, the deformability of polymer concrete is higher than that of Portland cement concrete. However, considering the four fillers employed in this study, it was determined to be advantageous to use fly ash in the repair of ordinary Portland cement concrete structures because the setting shrinkage, coefficient of thermal expansion, and modulus of elasticity were found to be the lowest. This is a key result of this study.  
Basic data for EP polymer concrete, including the modulus of elasticity, setting shrinkage, and thermal expansion, were determined in the present work. Based on this research, further study of the compatibility and dimensional stability of EP polymer concrete is required for field application.  
This research received no external funding.  
The author is very grateful to former collaborator [PERSON] from Kangwon National University for the assistance in conducting the experiment.  
The authors declare no conflicts of interest.