## 3 Experimental Results  
### Heat of Hydration  
The hydration heat results are shown in Figure 3. The hydration heat release rate test results are shown in Figure 3a. Overall, the hydration heat release can be divided into an initial rapid heat release stage, a latent period, an accelerated reaction period, and a diffusion-controlled deceleration period. The first peak of the accelerated reaction period occurs at around 12 h, which is mainly due to the hydration reaction of C3S. Next, there is a higher exothermic peak, which is due to the exotherm caused by the \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Identification** & **SiO2** & **Al2O3** & **CaO** & **Fe2O3** & **MgO** & **Na2O** & **K2O** & **ZnO** & **TiO2** & **SO3** & **LOI x** \\ \hline OPC & 19.40 & 4.46 & 64.20 & 3.00 & 2.29 & 0.12 & 0.98 & 0.06 & 0.23 & 3.83 & 1.43 \\ Quartz & 99.0 & 0.25 & - & - & - & - & - & - & 0.11 & - & 0.62 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Chemical compositions of cement and quartz. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Group** & **OPC** & **Quartz** & **Sand** & **Water** & **Water/(Cement + Quartz)** \\ \hline \multirow{3}{*}{Paste} & Qu0 & 100 & 0 & - & 50 & 0.5 \\  & Qu7.5 & 92.5 & 7.5 & - & 50 & 0.5 \\  & Qu15 & 85 & 15 & - & 50 & 0.5 \\ \hline \multirow{3}{*}{Mortar} & Qu0 & 100 & 0 & 200 & 50 & 0.5 \\  & Qu7.5 & 92.5 & 7.5 & 200 & 50 & 0.5 \\ \cline{1-1}  & Qu15 & 85 & 15 & 200 & 50 & 0.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Mixture of samples. secondary dissolution of C3A. In addition, we can see that the heat release rate decreases when the substitution rate of the quartz powder increases from 0 to 7.5% and 15%. This is mainly due to the dilution effect of the quartz powder [31]. In addition, when the substitution rate increases from 7.5% to 15%, we can see that the heat release rate increases during the accelerated reaction period. This may be because the cement we used contains about 5% calcium carbonate [34]. In the early stages of the hydration reaction, calcium carbonate basically does not react. Therefore, calcium carbonate and quartz powder are both non-reactive admixtures. Cement with mineral admixtures generally contains at least two components. When the reactivity of mineral admixtures is much weaker than that of cement, such as limestone powder or quartz powder, the less reactive substances may become nucleation sites for the cement hydration process, thereby accelerating the hydration reaction of cement. The nucleation sites are related to the physical and chemical properties of the mineral admixture. Compared with quartz powder, limestone powder will produce calcium ions after dissolution. Therefore, when the particle size distribution is the same, the nucleation effect of limestone powder is stronger than that of quartz powder. In addition, the nucleation effect becomes obvious as the surface area of the filler increases. The nucleation effects of calcium carbonate and quartz powder are different. Therefore, when the substitution rate of quartz powder increases from 0 to 7.5% and 15%, the exothermic trend of hydration heat is inconsistent with the substitution rate trend of the quartz powder. The measurement results for the cumulative hydration heat are shown in Figure 3b. In the early stage of the hydration reaction (the first three days), as the substituted amount of quartz powder increases, the cumulative hydration heat increases. This is mainly because the nucleation effect of the quartz powder accelerates the hydration reaction of the cement. In the later stage of the hydration reaction (about seven days), as the substituted amount of quartz powder increases, the cumulative hydration heat decreases. This is mainly due to the diluting effect of the quartz powder, and this is consistent with research by [PERSON] et al. [23]. The nucleation effect and dilution effect of the quartz powder exist at the same time. In the early stage, the nucleation effect dominates, and in the later stage, the dilution effect dominates.