## 3 Life Cycle Inventory
### Maintenance
The products required for the rehabilitation were derived from the road stratigraphy and have been reported in Table 8.  
The transportation of the equipment and materials to the construction site was considered using the same procedure as that used for the construction phase. When the wear and binder layer rehabilitation takes place, the lateral areas and the central one are milled separately: A 1.5 m wide milling machine, with a milling depth of 13 cm, is used for the two sides. The fuel consumption required to mill 1 km of road at a milling depth of 13 cm was derived from the milling speed (using speed-depth diagrams supplied by the manufacturer) and the hourly consumption was multiplied by two (because of the two lateral areas). The same procedure as the wear rehabilitation was adopted for the central areas. It was assumed that the precast coils would remain in the ground for the entire operation. In order to provide a benchmark, the life cycle of a traditional road has been considered as a reference. Since the subject of the study is the revamping of an existing t-road into an e-road, in order to make fair comparison, it has been supposed that the reference t-road at time 0, when the e-road was built starting from a t-road, underwent a refurbishment of the wear and binder layers. Thus, only the maintenance operations have been included in the analysis, while the base and subbase remain unchanged in both of the configurations. In order to make a fair comparison, only the regular maintenance operations of the t-road have been considered for the same lifespan of the e-road (20 years). The frequency of the maintenance operations was taken from the literature. The rehabilitation of the wear layer is expected every 5 years, while rehabilitation of the wear and binder layers is expected at least once in the lifetime of the road [24]. The wear and binder layer maintenance operations have been modelled using the same machinery used for the e-road. The amount of asphalt that has to be replaced has been calculated considering the geometry of the road (the layer thicknesses are supposed to be the same as those of the e-road). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Machinery** & **Operation** & **Characteristics** & **Fuel Consumption** \\ \hline \multirow{2}{*}{Milling machine} & Removal of the upper part of the wear layer & Operating width 2 m; Weight 28.9 t. & \multirow{2}{*}{55.66 kg/km} \\  & Removal of the upper part of the wear layer & Two passages & \\ \hline \multirow{2}{*}{Milling machine (fine)} & Fine milling of the wear layer closer to the coils & \multirow{2}{*}{Milling width; Milling depth 1 mm; Speed 2.5 km/h; Hourly consumption 30 L/h} & \multirow{2}{*}{20.04 kg/km} \\  & & & \\ \hline \multirow{2}{*}{Emulsion sprayer machine} & Bitumen emulsion deposition & \multirow{2}{*}{265 KW power; Operating width 4 m} & \multirow{2}{*}{0.346 kg/km} \\  & & & operating speed 20 km/h; fuel consumption & \\  & & & 8,3 L/h & \\ \hline \multirow{2}{*}{Paver} & \multirow{2}{*}{Asphalt deposition} & Operating width of 3.75 m; power 130 kW; & \multirow{2}{*}{69 kg/km} \\  & & weight 19 t; Speed 1028.8 m/h; Fuel consumption 23.2 L/h & \\ \hline \multirow{2}{*}{Roller} & \multirow{2}{*}{Compacting wear layer} & Weight 12.5 t; Roller width 2 m; Nominal & \multirow{2}{*}{767 kg/km} \\  & & Power 100 kW; Speed 0.27 km/h; Fuel consumption 21.2 L/h Passages: 6 & \\ \hline \hline \end{tabular}
\end{table} 
Table 7: The equipment consumptions for wear layer rehabilitation. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Materials** & **Use** & **Quantity** \\ \hline \multirow{2}{*}{Asphalt Bituminous emulsion} & Wear layers & 512,406 kg/km \\  & Bonding between layers & 2190 kg/km \\ \hline \hline \end{tabular}
\end{table} 
Table 8: The materials required for wear layer rehabilitation.