## 2 Reverification of the Multicomponent Hydration Model
### Target Concerns  
The original model explained in Section 3.1 and the compressive strength development model, which is formulated as a function of the porosity of capillary pores, have been verified for various cement types and W/C mixtures to predict the weight loss and growing strength under various short-term conditions [1; 21; 24; 25]. According to the model, the compressive strength develops with the decrease of capillary pores, and asymptotically approaches the ultimate value [21]. However, further verifications are required especially for various long-term and high temperature conditions as pointed out in the introduction. Hence, the comparative studies were conducted between the analyses and the experiments under exposure to thermal environments even after fine micro-pore structures were formed. The analyses were based on the modified model after the reverification of Part A in Figure 5, while referring to the past experiments whose conditions are listed in Table 4. All the specimens are made of ordinary portland cement (OPC). The comparative results are presented in Figures 16-18. Here, the cases named from (a) to (i) in Figure 16 basically consist of \"the duration under sealing at 20 \({}^{\circ}\)C\" and \"the subsequent exposure conditions\". For example, 20S means that the specimen continues to be kept under sealing at 20 \({}^{\circ}\)C, whilst 91d-60 RH90 means that it is exposed to the environment at 60 \({}^{\circ}\)C in R.H. 90% after sealing at 20 \({}^{\circ}\)C for 91 days. In Figure 16, it was demonstrated that every numerical case agrees well with \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Verification Target** & **Type of Specimen W/C** & **Curing Condition** & **Reference** \\ \hline Compressive strength & \begin{tabular}{c} Mortar \\ 30\% \\ \end{tabular} & \begin{tabular}{c} Exposure to a given environment after sealing \\ at 20 \({}^{\circ}\)C for a given age as shown in Figure 16 \\ \end{tabular} & [PERSON] [27] \\ \hline Weight loss & \begin{tabular}{c} Mortar \\ 35\%, 55\% \\ \end{tabular} & \begin{tabular}{c} Sealing at 20 \({}^{\circ}\)C for 1 day, water curing at \\ 20 \({}^{\circ}\)C for 60 days, and then exposure to 20 \({}^{\circ}\)C \\ in R.H. 70\% \\ \end{tabular} & [PERSON] [28] \\ \hline Weight loss & \begin{tabular}{c} Concrete \\ 60\% \\ \end{tabular} & \
\begin{tabular}{c} - \\ - \\ - \\ - \\ - \\ - \\ \end{tabular} &
\begin{tabular}{c} 2C: Moisture curing at 38 \({}^{\circ}\)C for 28 days \\ and then exposure to 38 \({}^{\circ}\)C in R.H. 40\% \\ 3C: Moisture curing at 38 \({}^{\circ}\)C for 7 days \\ and then exposure to 38 \({}^{\circ}\)C in R.H. 40\% \\ 4C: Moisture curing at 38 \({}^{\circ}\)C for 1 day \\ and then exposure to 38 \({}^{\circ}\)C in R.H. 40\% \\ 5C: Exposure to 38 \({}^{\circ}\)C in R.H. 40\% \\ \end{tabular} & Cano [29] \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Experimental conditions in the past studies. Figure 15: Enhanced moisture isotherm model of interlayer water under different temperature conditions [1; 24]. the compressive strength obtained in the experiment during the period of sealing at 20 \({}^{\circ}\)C, but the numerical strength is overestimated, while the weight loss is greatly underestimated, after exposure to 60 \({}^{\circ}\)C. Although the horizontal plateau of the compressive strength in some figures is observed, this suggests that capillary pores are completely filled with hydration products, leading to the ultimate value according to the formulation. In Figure 17, the analysis of W/C55% provided good agreement with the experiment, but that of W/C35% was not proper due to underestimation. Although Figure 18 targeted the normal W/C mixtures of 60%, the analysis, except for the case 5C without moisture curing, agreed well with the experiment. Figure 16: Comparison of compressive strength and weight loss based on the modified model (W/C = 30%) [27]. (Dot: experiment, Solid/chain line: analysis). Figure 17: Comparison of weight loss based on the modified model (W/C = 35%, 55%) [28].