## 4 Computational Experiments
### Experimental Setting
Furthermore, the currently available disposal facilities for construction waste in Guangzhou are essentially capable of meeting the past five years' production of construction waste [51]. Based on the production of construction waste in 2019 [51], the annual processing capacity of existing disposal facilities is estimated. From there, the amount of construction waste is adjusted according to the proportion of construction waste generated at each construction site each year. Finally, the total amount of construction waste that needs to be handled by the newly constructed recycling plants can be determined. During the construction phase of building projects, typically, the quantity of construction waste generated amounts to approximately 10-20% of the total raw material input for the project, with an assumed median value of 15% [51]. Following this, this study calculates the demand for recycled materials based on the projected quantities of construction waste produced by newly constructed buildings in each district. Subsequently, by subtracting the production capacity of existing recycling plants from the proportionate demand for construction waste raw materials across worksites, we are able to get the volume of recycled building materials required by construction sites, as shown in Table 4. This study benchmarks the forecasted values and randomly generates the values of \(V_{s,\omega}\), \(s=S+1,\ldots,S+S^{\prime}\), \(\omega=1,\ldots,\Omega\), within the range of 80-120% of the forecasted values for the construction of 20 different scenarios. Then, we introduce the data regarding transportation and disposal costs. The geographic locations of construction sites, potential recycling centers, and landfill sites are shown in Figure 1. The distance between these facilities and construction sites is calculated using Euclidean distance, and the transportation cost of \(1\) ton of construction waste is 3.5 CNY per kilometer [55]. \(C_{s,r}^{2}\) is presented in Table 5.  
Before the establishment of recycling centers, all construction waste was disposed of via landfilling, thereby indicating that existing landfills could accommodate the construction waste generated entirely in Guangzhou. To alleviate transportation costs, construction waste from construction sites that is unable to be transported to recycling plants will be directed to the nearest landfills. A processing fee of 30 CNY/ ton of construction waste is imposed. Thus, the total cost, denoted as \(C_{s}^{3}\), comprises both processing and transportation expenses (refer to Table 6). \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline
**CNY/ton** & **YX** & **LW** & **TH** & **HZ** & **BY** & **PY** & **HP** & **HD** & **NS** & **ZC** & **CH** \\ \hline CX1 & 246.46 & 271.89 & 219.22 & 254.23 & 190.21 & 280.67 & 179.71 & 190.91 & 360.21 & 134.50 & 69.14 \\ CX2 & 365.07 & 390.88 & 334.92 & 369.54 & 311.71 & 387.97 & 288.85 & 310.76 & 451.51 & 204.34 & 121.50 \\ CX3 & 305.59 & 330.84 & 278.82 & 313.82 & 247.98 & 339.76 & 238.71 & 238.87 & 416.14 & 177.97 & 50.93 \\ CX4 & 214.94 & 283.09 & 196.28 & 229.38 & 152.84 & 266.80 & 173.31 & 131.05 & 359.74 & 175.59 & 119.02 \\ HDX1 & 174.93 & 186.69 & 180.71 & 199.21 & 129.26 & 249.32 & 196.46 & 59.85 & 353.53 & 258.45 & 235.26 \\ HDX2 & 145.62 & 148.76 & 164.25 & 171.19 & 125.54 & 221.87 & 196.96 & 92.63 & 324.92 & 279.61 & 282.12 \\ NX1 & 171.71 & 168.69 & 168.07 & 146.54 & 221.44 & 96.12 & 185.30 & 290.50 & 68.84 & 257.20 & 371.03 \\ ZX1 & 152.56 & 176.94 & 117.13 & 146.74 & 131.18 & 155.69 & 65.08 & 188.75 & 227.40 & 99.38 & 200.59 \\
**Minimum price** & **145.62** & **148.76** & **117.13** & **146.54** & **125.54** & **96.12** & **65.08** & **59.85** & **68.84** & **99.38** & **50.93** \\ \hline \end{tabular}
\end{table} 
Table 6: The disposal cost of 1 ton construction waste in landfills.