## 2 Machine Learning Algorithm
### Database of Concrete Mixtures  
For training and testing the MLA, concrete mixtures and experimental data for the concrete compressive strength were needed. In this study, 4279 data points suitable for the learning and testing of the algorithm among the data presented by [PERSON] et al. [19] were utilized. The \(f^{\prime}_{c.meas}\) of data ranges from 7 MPa to 100 MPa and were classified into the following ranges: 7-20 MPa, 20-30 MPa, 30-40 MPa, 40-60 MPa, 60-80 MPa, and 80-100 MPa. Furthermore, they were classified according to the mixing form: ordinary Portland cement (OPC), OPC + FA (fly ash), OPC+ blast furnace slag (GGBS), and OPC + FA + GGBS. The type of binder, compressive strength ranges and maximum and minimum values of each ingredient are presented in Table 1. 70% of the classified data were used as a training dataset, and the other 30% were utilized for the accuracy verification of the MLA. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{\begin{tabular}{c} **Type of** \\ **Binder** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Range of** \\ \(f^{\prime}_{c.meas}\) \\ \end{tabular} } & \multirow{2}{*}{**Data**} & \multirow{2}{*}{\begin{tabular}{c} **W** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **C** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **W/B** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **S** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **G** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Max. of** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **FA** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **GGBS** \\ \end{tabular} } \\ \cline{2-2} \cline{6-11}  & & **MPa** & & & & & & & & & \\ \hline \multirow{6}{*}{OPC} & 7 to 20 & 122 & 90–216 & 150–444 & 30–89 & 592–1039 & 452–1503 & 10–40 & - & - \\  & 20 to 30 & 488 & 135–247 & 251.67–630 & 30–80 & 166–1073 & 452–1260 & 10–40 & - & - \\  & 30 to 40 & 671 & 69–247 & 272.31–720 & 14–67 & 165–1186 & 32–1599 & 10–30 & - & - \\  & 40 to 60 & 919 & 108–280 & 294–900 & 20–60 & 162–1731 & 0–1567 & 10–25 & - & - \\  & 60 to 80 & 438 & 108–232 & 292–900 & 20–50 & 346–2022 & 0–1416 & 13–25 & - & - \\  & 80 to 100 & 224 & 97–200 & 396.51–847.62 & 20–40 & 465–1122 & 554–1416 & 15–25 & - & - \\ \hline \multirow{6}{*}{OPC + FA} & 7 to 20 & 111 & 144–221 & 135–371 & 50–133 & 50–890 & 842–1230 & 13–25 & 18–247.5 & - \\  & 20 to 30 & 375 & 142–383 & 135–245 & 40–107 & 496–940 & 28–1299 & 13–25 & 17–270 & - \\  & 30 to 40 & 226 & 126–220 & 200–581 & 32–80 & 37–950 & 60–1230 & 13–80 & 13–380 & - \\  & 40 to 60 & 181 & 126–220 & 163–680 & 25–100 & 168–876 & 105–1422 & 13–25 & 27–437 & - \\  & 60 to 80 & 97 & 148–180 & 298–650 & 25–60 & 391–856 & 751–1393 & 13–25 & 32–420 & - \\  & 80 to 100 & 8 & 157–165 & 385–597 & 26–43 & 587–651 & 977–1058 & 19–20 & 62.8–192 & - \\ \hline \multirow{6}{*}{OPC + FA} & 7 to 20 & 13 & 175–182 & 73–293 & 64–249 & 655–943 & 899–1223 & 20 & - & 23–234 \\  & 20 to 30 & 50 & 150–220 & 110–312 & 50–164 & 625–856 & 864–1223 & 19–25 & - & 35–234 \\ \cline{1-1}  & 30 to 40 & 65 & 150–220 & 150–495 & 5–125 & 605–864 & 743–1111 & 19–25 & - & 8–330 \\ \cline{1-1}  & 40 to 60 & 73 & 150–220 & 110–583.33 & 5-164 & 272–864 & 743–1062 & 19–25 & - & 32.2–408.33 \\ \cline{1-1}  & 60 to 80 & 68 & 120–175 & 140–567 & 20–118 & 272–803 & 898–1099 & 20–25 & - & 43.25-420 \\ \cline{1-1}  & 80 to 100 & 45 & 135.2–175 & 192–7778 & 23–83 & 263–1146 & 667–114 & 20 & - & 100–448 \\ \hline \multirow{6}{*}{OPC + FA} & 7 to 20 & 29 & 108–180 & 162–227 & 54–110 & 834–982 & 885–993 & 20 & 25–45 & 33–113 \\ \cline{1-1}  & 20 to 30 & 59 & 105–182 & 158–296 & 45–108 & 776–950 & 884–1134 & 20 & 17–96 & 22.8–184 \\ \cline{1-1}  & 30 to 40 & - & - & - & - & - & - & - & - \\ \cline{1-1}  & 4 to 60 & 17 & 157–177 & 140–515 & 31–114 & 701–874 & 850–957 & 20–25 & 31–114 & 19–180 \\ \cline{1-1}  & 60 to 80 & - & - & - & - & - & - & - & - \\ \cline{1-1}  & 80 to 100 & - & - & - & - & - & - & - & - \\ \hline \hline \end{tabular}
\end{table}