# Carbon Emission Analysis of RC Core Wall-Steel Frame Structures
## 3 Results
### Impact of Material Manufacturing Processes  
According to Section 3.2, it is evident that the production of the main building materials, specifically concrete and steel, constitutes the most significant portion of carbon emissions throughout the life cycle of super high-rise buildings with RC core wall-steel frame structures. The carbon emissions associated with these materials are significantly influenced by the specific manufacturing processes and raw materials utilized. Consequently, in this section, the impact of different manufacturing processes and raw materials on carbon emissions is discussed. Please note that in this section, only the material manufacturing process is altered without changing the material strength or structural form. Therefore, the structures discussed below all meet the safety requirements. Mineral admixtures are often processed from waste products, making them a sustainable choice to replace cement and reduce the carbon emissions of concrete. Here, concrete mixed with fly ash and composite mineral admixtures is mainly discussed. The CEFs for these concretes are detailed in Table 8.  
In this section, only steel and concrete are considered for variations. Therefore, only the related carbon emissions of steel and concrete are calculated for comparative analysis. Table 9 shows the carbon emissions during the production and transportation stages for the models utilizing ordinary concrete, fly ash concrete, and concrete with composite mineral admixtures, respectively, with the same type of steel. Figure 8: Carbon emission across different main stages. As shown in Figure 9, the carbon emissions of the model are reduced by 5.9% when utilizing fly ash concrete and by 11.7% when utilizing concrete with composite mineral admixtures. This indicates that when employing significant amounts of cement substitutes (e.g., fly ash, composite mineral admixtures, etc.) in buildings, the carbon emissions can be substantially reduced. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Concrete Grade** & **Admixture Type** & \begin{tabular}{c} **Carbon Emission Factor** \\ **(kgCO\({}_{2}\)e/m\({}^{3}\))** \\ \end{tabular} \\ \hline C30 & \begin{tabular}{c} Ordinary concrete \\ Single admixture of fly ash \\ Composite mineral admixture \\ \end{tabular} & 295.00 \\ C30 & \begin{tabular}{c} Single admixture of fly ash \\ Composite mineral admixture \\ \end{tabular} & 208.20 \\ \hline C40 & \begin{tabular}{c} Ordinary concrete \\ Single admixture of fly ash \\ Composite mineral admixture \\ \end{tabular} & 230.35 \\ C50 & \begin{tabular}{c} Ordinary concrete \\ Single admixture of fly ash \\ Composite mineral admixture \\ \end{tabular} & 185.25 \\ \hline C60 & \begin{tabular}{c} Ordinary concrete \\ Single admixture of fly ash \\ Composite mineral admixture \\ \end{tabular} & 385.00 \\ C50 & \
\begin{tabular}{c} Single admixture of fly ash \\ Composite mineral admixture \\ \end{tabular} & 286.26 \\ \hline C60 &
\begin{tabular}{c} Ordinary concrete \\ Single admixture of fly ash \\ Composite mineral admixture \\ \end{tabular} & 416.76 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: The carbon emission factors of concrete with different admixtures. Figure 9: Carbon emissions from different types of concrete. For steel, carbon emissions are correlated with manufacturing processes and the rate of utilizing recycled materials. Four scenarios are mainly investigated: blast furnace-basic oxygen furnace (BF-BOF), electric arc furnace (EAF), BF-BOF with 30% recycled scrap, and EAF with 80% recycled scrap. The CEFs for these four types of steel are presented in Table 10. The chosen usage rates of scrap steel are achievable for each process. The carbon emissions for each of the four scenarios mentioned are calculated and listed in Table 11.  
As shown in Figure 10, the carbon emissions of the model decrease by 23.8% when employing the EAF process.