## 2 Research Methodology
### Case Description
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sources (Uni)**} & **GWP (kg** & **AP (kg** & **EP** & **ODP (kg** & **POCP** & **ADP** \\  & **CO2** & **SO2** & **(kg-PO43–** & **CFC11** & **(kg-C2H4** & **(kg-Sb** \\  & **eq/m2)** & **eq/m2)** & **eq/m2)** & **eq/m2)** & **eq/m2)** \\ \hline Ready-mixed & \multirow{2}{*}{\(4.29\times 10^{2}\)} & \multirow{2}{*}{\(7.06\times 10^{-1}\)} & \multirow{2}{*}{\(8.20\times 10^{-2}\)} & \multirow{2}{*}{\(4.59\times 10^{-5}\)} & \multirow{2}{*}{\(1.16\times 10^{0}\)} & \multirow{2}{*}{\(2.55\times 10^{1}\)} \\ concrete & & & & & & \\ \cline{1-1} Rebars & \multirow{2}{*}{\(4.38\times 10^{-1}\)} & \multirow{2}{*}{\(1.40\times 10^{-3}\)} & \multirow{2}{*}{\(1.79\times 10^{-4}\)} & \multirow{2}{*}{\(1.04\times 10^{-8}\)} & \multirow{2}{*}{\(3.41\times 10^{-4}\)} & \multirow{2}{*}{\(2.79\times 10^{-3}\)} \\ Forms & \multirow{2}{*}{\(8.18\times 10^{2}\)} & \multirow{2}{*}{\(5.07\times 10^{0}\)} & \multirow{2}{*}{\(7.23\times 10^{0}\)} & \multirow{2}{*}{\(3.43\times 10^{-5}\)} & \multirow{2}{*}{\(4.05\times 10^{0}\)} & \multirow{2}{*}{\(2.72\times 10^{0}\)} \\ Steel decking & \multirow{2}{*}{\(4.38\times 10^{-1}\)} & \multirow{2}{*}{\(140\times 10^{-3}\)} & \multirow{2}{*}{\(1.79\times 10^{-4}\)} & \multirow{2}{*}{\(1.04\times 10^{-8}\)} & \multirow{2}{*}{\(3.41\times 10^{-4}\)} & \multirow{2}{*}{\(2.79\times 10^{-3}\)} \\ Anchoring & \multirow{2}{*}{\(2.09\times 10^{0}\)} & \multirow{2}{*}{\(1.20\times 10^{-2}\)} & \multirow{2}{*}{\(3.26\times 10^{-3}\)} & \multirow{2}{*}{\(1.01\times 10^{-4}\)} & \multirow{2}{*}{\(2.03\times 10^{-4}\)} & \multirow{2}{*}{\(8.13\times 10^{-5}\)} \\ Void formers & \multirow{2}{*}{\(5.89\times 10^{1}\)} & \multirow{2}{*}{\(1.02\times 10^{-2}\)} & \multirow{2}{*}{\(1.74\times 10^{-3}\)} & \multirow{2}{*}{\(6.92\times 10^{-8}\)} & \multirow{2}{*}{\(3.35\times 10^{-2}\)} & \multirow{2}{*}{\(3.18\times 10^{-2}\)} \\ Concrete mixer & \multirow{2}{*}{\(6.74\times 10^{-1}\)} & \multirow{2}{*}{\(6.50\times 10^{-3}\)} & \multirow{2}{*}{\(1.03\times 10^{-3}\)} & \multirow{2}{*}{\(2.44\times 10^{-7}\)} & \multirow{2}{*}{\(1.12\times 10^{-3}\)} & \multirow{2}{*}{\(4.47\times 10^{-3}\)} \\
4.5-ton lorry & \multirow{2}{*}{\(4.29\times 10^{-3}\)} & \multirow{2}{*}{\(3.23\times 10^{-5}\)} & \multirow{2}{*}{\(5.75\times 10^{-6}\)} & \multirow{2}{*}{\(1.57\times 10^{-9}\)} & \multirow{2}{*}{\(9.61\times 10^{-6}\)} & \multirow{2}{*}{\(2.88\times 10^{-5}\)} \\
11.5-ton lorry & \multirow{2}{*}{\(4.01\times 10^{-3}\)} & \multirow{2}{*}{\(3.07\times 10^{-5}\)} & \multirow{2}{*}{\(4.47\times 10^{-6}\)} & \multirow{2}{*}{\(7.41\times 10^{-9}\)} & \multirow{2}{*}{\(2.12\times 10^{-5}\)} & \multirow{2}{*}{\(2.88\times 10^{-5}\)} \\ Diesel & \multirow{2}{*}{\(6.82\times 10^{-2}\)} & \multirow{2}{*}{\(1.40\times 10^{-4}\)} & \multirow{2}{*}{\(9.55\times 10^{-6}\)} & \multirow{2}{*}{\(1.23\times 10^{-10}\)} & \multirow{2}{*}{\(1.18\times 10^{-5}\)} & \multirow{2}{*}{\(2.16\times 10^{-2}\)} \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Factors of environmental impacts. Figure 4: Schematics of the slab systems. Figure 3: Typical floor plan of the studied building. The FPS is one of the reinforced concrete slab systems that directly connect slabs to columns, without the use of beams and girders. Since this slab system does not use beams and girders, there are several advantages, such as simple formworks during the construction phase, and enhanced serviceability for occupants during the operation phase. Likewise, the VDS is a newly developed slab system that reduces the self-weight of the slab, and this would make it possible to extend the span between columns. According to [PERSON] et al. [57], the nominal strength of the ORC and the VDS showed 20.3 kN and 75.7 kN, respectively. This result indicated that the structural performance of the VDS would be better than the ORC and potential replacement of the ORC to the VDS.