## 5 Case Study--LCA Results and Discussion
### Environmental Assessment
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Category** & **Unit** &
\begin{tabular}{c} **Transport** \\ **(82 km)** \\ \end{tabular} & **Plasticiser** & ** Cement** & **Water** & **Filler** \\ \hline GWP & kg CO\({}_{2}\) eq & \(6.06\times 10^{-1}\) & \(4.20\) & \(2.15\times 10^{2}\) & \(1.86\times 10^{-2}\) & \(1.56\) \\ ODP & kg CFC\({}^{-11}\) eq & \(1.11\times 10^{-7}\) & \(6.56\times 10^{-7}\) & \(6.54\times 10^{-6}\) & \(2.01\times 10^{-9}\) & \(1.69\times 10^{-7}\) \\ AP & kg SO\({}_{2}\) eq & \(2.07\times 10^{-3}\) & \(2.30\times 10^{-2}\) & \(3.75\times 10^{-1}\) & \(9.99\times 10^{-5}\) & \(8.63\times 10^{-3}\) \\ EP & kg PO\({}_{4}\)\({}^{3-}\) eq & \(3.99\times 10^{-4}\) & \(5.29\times 10^{-3}\) & \(9.79\times 10^{-2}\) & \(5.72\times 10^{-5}\) & \(2.28\times 10^{-3}\) \\ POPFP & kg NMVOC & \(2.83\times 10^{-3}\) & \(1.63\times 10^{-2}\) & \(3.73\times 10^{-1}\) & \(4.07\times 10^{-5}\) & \(8.58\times 10^{-3}\) \\ ADP & kg Sb eq & \(1.36\times 10^{-9}\) & \(2.75\times 10^{-5}\) & \(3.60\times 10^{-6}\) & \(2.65\times 10^{-8}\) & \(1.60\times 10^{-7}\) \\ ADP (fossil fuels) & MJ & \(8.65\) & \(9.54\times 10\) & \(7.88\times 10^{2}\) & \(2.02\times 10^{-1}\) & \(1.89\times 10\) \\ WU & m\({}^{3}\) & \(3.14\times 10^{-2}\) & \(3.57\) & \(1.39\times 10\) & \(1.52\) & \(1.54\) \\ CED & MJ & \(9.24\) & \(1.12\times 10^{2}\) & \(9.93\times 10^{2}\) & \(4.25\times 10^{-1}\) & \(2.29\times 10\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Environmental impacts for other components in precast concrete formulation. regarding filler transport of the linear model, due to the reduction in the current transport distance, just comparing the natural filler and the lime ash ones (82 km to 23 km). Table 7 shows the impacts associated with the transport of lime ash, as well as the impacts of producing concrete with lime ash. The difference in impacts of the linear and circular solution of precast concrete is achieved by the elimination of impacts associated with the disposal of waste in landfills and the elimination of impacts associated with the use of filler, as well as by reducing impacts on the transport of raw material alternative to the natural filler. This simple case of adoption of a circular model allows for a reduction between 1% to 3% of impacts compared to the linear solution (Table 7 and Figure 6), except in the eutrophication (EP) category, since the reduction is 99%, mainly due to the elimination of operations of landfill disposal of the lime ash waste (Table 3). Figure 6 shows the comparative results of the linear and circular models. The reduction of impacts in the circular model is not greater, because the rate of incorporation of filler/lime ash is low (4.4%) but it points to a clear trend of decrease in all parameters. The impacts of cement are high compared to other traditional raw materials (sands, gravel, water and superplasticiser) [10; 40]. Hence, the use of other wastes as alternative raw materials to other components should also be explored to further minimise impacts. Finally, in statistical terms, one must also say that, although the uncertainty was higher for some of the impact categories, practically for all environmental impact categories, the difference between the concrete reference (current product) and the concrete containing waste (paperChain solution) is positive, which means that the current system has a higher impact than the paperChain system solution as observed.