## 3 Results and Discussion
### Total Construction Waste Generation
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Building Materials**} & \multicolumn{4}{c}{**Total Waste Generation**} & \multicolumn{4}{c}{**Waste Generation per Unit Floor**} \\  & & \multicolumn{2}{c}{**(kg)**} & \multicolumn{2}{c}{**(kg/m\({}^{2}\))**} & \\ \cline{2-9}  & **SS** & **FPS180** & **FPS210** & **VSS** & **SS** & **FPS180** & **FPS210** & **VSS** \\ \hline \multirow{2}{*}{Ready-mixed concrete} & \multirow{2}{*}{65,350.766} & \multirow{2}{*}{64,527.346} & \multirow{2}{*}{65,519.371} & \multirow{2}{*}{56,902.747} & \multirow{2}{*}{67.838} & \multirow{2}{*}{66.984} & \multirow{2}{*}{68.013} & \multirow{2}{*}{59.069} \\  & & & & & & & & \\ \hline \multirow{2}{*}{Rebars} & \multirow{2}{*}{26,667.094} & \multirow{2}{*}{25,402.723} & \multirow{2}{*}{24,902.235} & \multirow{2}{*}{23,767.740} & \multirow{2}{*}{27.682} & \multirow{2}{*}{26.370} & \multirow{2}{*}{25.850} & \multirow{2}{*}{24.672} \\ \hline \multirow{2}{*}{Spacers} & \multirow{2}{*}{1456.555} & \multirow{2}{*}{1294.716} & \multirow{2}{*}{1375.635} & \multirow{2}{*}{687.818} & \multirow{2}{*}{1.512} & \multirow{2}{*}{1.344} & \multirow{2}{*}{1.428} & \multirow{2}{*}{0.714} \\ \hline \multirow{2}{*}{Forms} & \multirow{2}{*}{7886.970} & \multirow{2}{*}{7432.624} & \multirow{2}{*}{7537.920} & \multirow{2}{*}{2832.190} & \multirow{2}{*}{8.187} & \multirow{2}{*}{7.716} & \multirow{2}{*}{7.825} & \multirow{2}{*}{2.940} \\ \hline \multirow{2}{*}{Void formers} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{2014.901} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{2.092} \\ \hline Steel decking & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{1216.493} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{1.263} \\ \hline Anchoring metal & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{182.069} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0.189} \\ \hline Total & \multirow{2}{*}{101,361.385} & \multirow{2}{*}{98,657.409} & \multirow{2}{*}{99,335.161} & \multirow{2}{*}{87,603.958} & \multirow{2}{*}{105.220} & \multirow{2}{*}{102.413} & \multirow{2}{*}{103.116} & \multirow{2}{*}{90.939} \\ \hline \end{tabular} Note: SS is the solid slab, FPS 180 and FPS 210 are the flat plate slab with the thickness of 180 mm and 210 mm, and the VSS is the void slab system.  
\end{table} 
Table 3: The total waste generation of the case study building. lowest results among all four slab systems. For the void slab system, the steel decking played dual roles during the concrete curing process as well as acting as an additional structural material integrated with the slab itself. This made it possible to enhance the structural performance of the slab system as well as to reduce the generation of construction waste during the construction phase. In addition, the void formers produced approximately 2015 kg of the construction waste, which accounts for about 2.3% of the total waste generated during the void slab system construction. In particular, it was indicated that the amount of construction waste generated from the void slab system was small because the steel decking and the void formers were processed according to the specifications shown in the design drawings at the factory and brought to the construction site. The building materials processed at the factory would seem to show similar characteristics to the prefabrication method, which is suggested as one of the potential construction methods to mitigate on-site construction waste [3; 6; 17].