# Carbon Emission Analysis of RC Core Wall-Steel Frame Structures
## 3 Results
### Results of Carbon Emission Analysis
Additionally, it is assumed that the usage area for each of the three types of formwork is evenly divided. According to the calculation results from the Chenxi Quantity Calculation software for the model, the total formwork usage area is 101,447.614 m\({}^{2}\). Thus, the usage area for each type of formwork is 33,815.871 m\({}^{2}\). The carbon emissions from formwork during the construction phase are calculated as shown in Tables 4 and 5. Figure 4: Carbon emission shares during production stage. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Material Category** & **Quality (t)** & **Distance (km)** &
\begin{tabular}{c} **Carbon Emission** \\ **(tCO2e)** \\ \end{tabular} \\ \hline Steel & 3801.573 & 500 & 197.682 \\ Concrete & 27,488.19 & 40 & 114.351 \\ Gypsum & 209.692 & 500 & 10.904 \\ Wood & 53.001 & 500 & 2.756 \\ Glass, doors, windows, etc. & 468.304 & 500 & 24.352 \\ Coatings and membranes & 164.272 & 500 & 8.542 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Carbon emissions for main materials during transportation stage. The carbon emission for formwork amounts to 42.899 tCO\({}_{2}\)e. Given the same area, aluminum formwork has the lowest carbon emissions. The carbon emission shares of various types of formwork are shown in Figure 6. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Formwork Type** & **Area (m2)** & \begin{tabular}{c} **Thickness** \\ **(mm)** \\ \end{tabular} & \
\begin{tabular}{c} **Density** \\ **(t/m3)** \\ \end{tabular} & **Turnover** &
\begin{tabular}{c} **Carbon** \\ **Emission** \\ **(tCO\({}_{2}\)e)** \\ \end{tabular} \\ \hline Steel & 33,815.871 & 8 & 7.85 & 35 & 14.501 \\ Aluminum & 33,815.871 & 5 & 2.70 & 35 & 6.782 \\ Wood & 33,815.871 & 25 & 0.42 & 4 & 13.167 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Carbon emissions for production of formwork. Figure 5: Carbon emission shares during transportation stage. Figure 6: Carbon emission shares for different formwork. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Formwork Type** & **Unit** & **Amount** & \
\begin{tabular}{c} **Distance** \\ **(km)** \\ \end{tabular} & **Turnover** &
\begin{tabular}{c} **Carbon** \\ **Emission** \\ **(tCO\({}_{2}\)e)** \\ \end{tabular} \\ \hline Steel & t & 2123.637 & 500 & 35 & 3.155 \\ Aluminum & t & 456.514 & 500 & 35 & 0.678 \\ Wood & m3 & 355.667 & 500 & 4 & 4.616 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Carbon emissions for transportation of formwork. Combining the calculation results from Tables 4 and 5 with the carbon emissions for energy consumption during the construction stage, the total carbon emissions for the construction stage \(\rm C_{cons}\) are calculated to be 764.785 \(\rm{tCO_{2}e}\). Finally, the reduction in carbon emissions from the recycling and reuse of waste materials can be calculated with Equation (6). The results are shown in Table 6.  
The reduction in carbon emissions from the recycling of construction waste amounts to 9657.378 \(\rm{tCO_{2}e}\). Figure 7 illustrates the shares of carbon emission reductions for each category of recycled construction waste. Consequently, the carbon emissions for the main stages in the life cycle of the building for the model can be summarized in Table 7.  
The total carbon emissions for the materialization stage of the model amount to 14,337.903 \(\rm{tCO_{2}e}\). The carbon emissions per unit area of the building are 0.46 \(\rm{tCO_{2}e}/\rm{m^{2}}\), and the annual carbon emissions per unit area of the building are 9.13 \(\rm{kgCO_{2}e}/\rm{(m^{2}\cdot year)}\)