# Carbon Emission Analysis of RC Core Wall-Steel Frame Structures
## 4 Discussion  
This chapter discusses low-carbon construction strategies for super high-rise buildings with concrete core wall-steel frame structures based on the results presented above. According to the findings, carbon emissions generated during the production stage significantly dominate emissions throughout the entire materialization stage. Therefore, formulating targeted strategies to reduce carbon emissions during material production is particularly critical. Steel offers good seismic performance and low weight but has a high carbon emission factor, as shown in Table 11. In contrast, concrete features strong plasticity and can be adapted to various structural systems, with a lower carbon emission factor but a higher weight. The hybrid structure of steel and concrete can combine the advantages of both materials, thus reducing carbon emissions. Furthermore, utilizing 3R (reducible, recyclable, reusable) materials can decrease the frequency of resource extraction and reduce carbon emissions during the production process of building materials.  
In addition, an optimized manufacturing process of building materials not only directly reduces carbon emissions but also enhances the strength and corrosion resistance of materials. This improvement in material efficiency decreases the amount of building materials needed, thereby indirectly reducing the carbon emissions associated with buildings. Based on the results in Section 3.3, incorporating fly ash alone in concrete and adding composite mineral admixtures results in carbon emission reduction rates of 5.9% and 11.7%, respectively. For steel, adopting the EAF results in a carbon emission reduction rate of 23.8%. When 30% of recycled scrap steel is utilized in the BF-BOF process, the carbon emission reduction rate is 22.2%. Moreover, when the EAF process utilizes 80% recycled scrap steel, the carbon emission reduction reaches 56.4%. Compared to different admixtures in concrete, optimizing the steel manufacturing process has a more significant effect in reducing carbon emissions in super high-rise buildings.  
According to Equation (3), the carbon emissions during the transportation stage are influenced by the distance from the production site to the construction site, the weight of the building materials being transported, and the mode of transportation. Therefore, strategies for reducing carbon emissions at this stage include prioritizing locally sourced building materials to reduce transportation distances and lower carbon emissions. In addition, choosing transportation methods with lower carbon emission factors, including  
Figure 10: Carbon emissions from different manufacturing processes of steel.  
opting for gasoline-fueled vehicles over diesel-fueled ones for road transport, can also contribute to the reduction in carbon emissions.  
During the construction stage, carbon emissions mainly originate from construction tools, including formwork, energy consumption of machinery, and related emissions from labor activities. Therefore, adopting prefabricated construction methods and selecting solutions with higher prefabrication rates can effectively reduce the utilization of formwork and improve construction efficiency. Additionally, introducing green construction technologies and prioritizing machinery with higher energy efficiency helps minimize energy consumption during equipment operation. Lastly, enhancing green construction management through optimized processes not only boosts construction efficiency but also reduces material waste throughout the construction process.  
Regarding the waste recycling stage, the method of handling discarded materials is crucial. Implementing optimized demolition plans enhances the recycling rate of discarded materials and reduces pollution generated during demolition. Moreover, expanding methods for reusing discarded materials, including employing them for office area partitions, further enhances sustainable practices.