## 3 Testing Plan and Methods
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Study Step**} & \multirow{2}{*}{**Asphal Mix**} & \multicolumn{2}{c}{**Additive**} & \multirow{2}{*}{**Temperature \({}^{\circ}\)C**} & \multirow{2}{*}{**Tests**} \\ \cline{3-3} \cline{5-6}  & & **Type** & & & \\ \hline \multirow{5}{*}{Effect of different additives on WMA behaviour} & HMA165 & - & - & 165 & \\ \cline{2-6}  & WMA-1-0.5-145 & A1 & & & \\ \cline{2-6}  & WMA-2-0.5-145 & A2 & 0.5 & 145 & Workability \\ \cline{2-6}  & WMA-3-0.5-145 & A3 & & & I. tensile strength \\ \cline{2-6}  & WMA-1-0.5-120 & A1 & & & Water sensitivity \\ \cline{2-6}  & WMA-2-0.5-120 & A2 & 0.5 & 120 & Stiffness Triaxial \\ \cline{2-6}  & WMA-3-0.5-120 & A3 & & & \\ \hline \multirow{5}{*}{Optimisation of WMA design} & HMA165 & - & - & 165 & \\ \cline{2-6}  & WMA-5-0.5-145 & & 0.5 & & \\ \cline{2-6}  & WMA-5-0.05-145 & & 0.05 & & \\ \cline{2-6}  & WMA-S-0.5-120 & Selected & 0.5 & & \\ \cline{2-6}  & WMA-S-0.05-120 & & 0.05 & 120 & Stiffness Triaxial \\ \hline \multirow{2}{*}{Production of WMA in asphalt plant} & HMA165 & - & - & 165 & Density \\ \cline{2-6}  & WMA-S-S-S & Selected & Selected & Selected & Water sensitivity \\ \cline{2-6}  & WMA-S-S-S & Selected & Selected & & Stiffness Triaxial \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Testing plan. The second step of the testing plan consisted of studying the effect of the dosage of additive used (for the additive selected as the most appropriate in the previous step) while evaluating the impact of manufacturing temperature. This step was carried out with the aim of both optimising the design of the WMA, and obtaining a mechanical performance that is comparable with the conventional HMA. To do so, the behaviour of the asphalt mix was examined when manufactured at 145 \({}^{\circ}\)C and 120 \({}^{\circ}\)C by using 0.5% of additive (quantity employed in the previous step) and 0.05%. The percentage was considerably reduced in order to clearly identify the effect of the quantity of this component on the behaviour of the mixture, analysing whether this reduction in additive plays an essential role. Further, the choice of dosage was guided by the manufacturer's suggestion for finding the optimal solution to reduce production costs associated with using the chemical agent. On the other hand, in addition to the WMA mixtures, the performance of a conventional HMA was evaluated for use as a reference for analysing the influence of the additive. The properties evaluated were the workability and compatibility of the different solutions (which included determining the tensile strength), stiffness modulus [21], water sensitivity [22], and triaxial test [23]. The third study step involved the production of the laboratory-designed WMA in a conventional asphalt plant, in accord with the results obtained in the previous stages. In addition, a trial section was paved with both the WMA and the conventional HMA (used as a control) in order to study the long-term behaviour of these mixtures in further studies. During the spreading process, samples of both types of asphalt mix were collected in order to study their behaviour in laboratory, and to then assess the viability of manufacturing this kind of material in conventional asphalt plants. The tests developed to evaluate the response of both mixtures were density [24], stiffness modulus [21], water sensitivity [22], and triaxial test [23]. The workability test was developed by using a gyratory compact that allows for observing the relationship between the energy transmitted to the specimen and the level of compaction obtained, by analysing the aptitude of the material to be compacted at low temperatures. The total number of cycles applied was 210 gyros, in order to evaluate the evolution of the density of the material. In addition, after manufacturing 4 specimens for each mix, the indirect tensile strength was measured at 20\({}^{\circ}\) by using the method developed in [25].