# Coefficient of Thermal Expansion of RCA Concrete Made by Equivalent Mortar Volume
## 4 Test Results
### Concrete COTE Test Results  
Figure 4(a) shows the COTE of the concrete specimens of mix series 1. The error bar graph in Figure 4(a) represents the mean values of the individual. The values for CNR and ERR68-2 are the mean of 4 specimens, and the values for the other types of specimens are each the mean of 3 specimens. The mean CTE of the CNR specimen prepared using the reference natural coarse aggregate was 8.47 \(\times\) 10\({}^{-6}\)/\({}^{\circ}\)C, and the mean COTE values of the CRR68, CRR33, ERR68 and ERR68-2 specimens were 8.91, 8.93, 8.38 and 8.28 \(\times\) 10\({}^{-6}\)/\({}^{\circ}\)C, \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Specimens**} & \multirow{2}{*}{**Notation**} & \multicolumn{6}{c}{**Elastic Modulus, GPa**} \\ \cline{3-8}  & & **1** & **2** & **3** & **Avg.** & **Coefficient of Variation (\%)** \\ \hline Mortar 1 & E\({}_{mt}\) & 25.3 & 26.2 & 26.6 & 26.0 & 0.44 \\ \hline Mortar 2 & E\({}_{mt}\) & 25.1 & 26.0 & 25.4 & 25.5 & 0.21 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Elastic modulus of mortar. Figure 4: Cylindrical specimens prepared for TMA. respectively. The error of the reference CNR specimen and ERR68-2 was large in comparison with the mean values. Figure 5b shows the COTE values relative to the COTE of the reference CNR specimen. The COTE values of the CRR68 and CRR33 specimens were 5.2% and 5.4% higher, respectively, in comparison with the COTE of the reference specimen. On the contrary, the COTE values of the ERR68 and ERR68-2 specimens were 1.1% and 2.3% lower, respectively. Therefore, compared with the CR-mixes prepared by the conventional mix design, the COTE of the ER-mixes was lower by 6-7%. Figure 6a shows the mean COTE values of the concrete specimens of mix series 2. The specimens of mix series 2 were prepared using concrete mix that had been used for manufacturing PC culverts, and RP recycled aggregate obtained by crushing old PC culverts was applied. In mix series 2, the mean COTE of the CNR specimen prepared using the reference natural coarse aggregate was 8.54 \(\times\) 10\({}^{-6}\)/\({}^{\circ}\)C, and the mean COTE values of the CRP25 and CRP50 specimens, prepared using the conventional concrete mix design and RP at 25% and 50%, were 8.66 and 8.59 \(\times\) 10\({}^{-6}\)/\({}^{\circ}\)C, respectively. The COTE values of the ERP25 and ERP50 specimens, prepared by EMV mix design, were coincidently the same at 8.45 \(\times\) 10\({}^{-6}\)/\({}^{\circ}\)C. The value of the CNP specimen is the mean of 3 specimens, and the values for the CRP25, CRP50, ERP25 and ERP50 specimens are each the mean of 6 specimens. Figure 5: COTE and relative values in test series 1. Figure 6: COTE and relative values in test series 2. As described above, the CRP and ERP series of mix series 2 were prepared respectively by using concrete in which RP recycled aggregate was coated with a cement paste dissociation agent intended for chloride penetration resistance, and concrete to which the cement paste dissociation agent was not applied. Assuming the coating agent did not affect the COTE, the COTE of the CRP series and ERP series specimens were each calculated as the mean of 6 COTE values. The errors of the CRP25 and ERP50 specimens were larger than those of the other specimens. Figure 5(b) shows the COTE relative to the mean COTE of the reference CNP specimen. The COTE values of the CRP25 and CRP50 specimens were 1.3% and 0.6% higher, respectively, than the COTE of the reference specimen. On the contrary, the COTE values of the ERP25 and ERP50 specimens were 1% and 1.1% lower, respectively. Figure 6(a) shows the mean COTE of the concrete specimens of mix series 3. The specimens of mix series 3 were prepared using the same PC culvert concrete mix as used in mix series 2, and by adding RA as another recycled aggregate.