## 2 Materials and Methods
### Measurement Method and Equipment  
Square prims were taken from precast pavements currently used in practice in Spain. Albedo average results (Rm), solar absorptance (\(\alpha\)), thermal emittance (\(\epsilon\)) and the temperature that each sample would reach (\(T_{s}\)) and its solar reflectance index (SRI) for three \begin{table}
\begin{tabular}{c c c} \hline \hline
**Code** & **Denomination and Description** & **Color** \\ \hline Glacier 1 and 2 & Concrete slabs aged in a natural manner & Glacial grey tone \\ Glacier 3 and 4 & Concrete slabs without ageing treatment and kept in factory & Glacial grey tone \\ Glacier 5 and 6 & New mix design used in concrete slabs without & Glacial grey tone \\  & ageing treatment & Glacial grey tone \\ Titanium & Concrete slabs without ageing treatment with high SRI & Clear grey with a slight white tinge \\  & index. Titanium colour & Clear grey with a slight yellow tinge \\  & Concrete slabs without ageing treatment with high SRI & Clear grey with a slight yellow tinge \\  & index. Dolomite colour & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Description and codification of the tested samples. Figure 1: QUADRO samples from top to bottom: first column: Glacier 1 and 2; second column: Glacier 3 and 4; third column: Glacier 5 and 6; and fourth column: titanium and dolomite. convection coefficients (\(h_{c}\)), corresponding to three wind speeds, were measured in cut concrete surfaces. They were dried prior to radiative properties measurement because the moisture of the material markedly modifies the reflectance of concrete surfaces. In order to calculate thermal emittance, hemispherical reflectance of pavements is measured with a single-beam FTIR Erkin Elmer Frontier Spectrophotometer, with a 75 mm integrating sphere coated with a gold diffusing material. Four readings of each pavement samples were measured (2500-17,000 nm) and thermal emittance was calculated using hemispherical spectral reflectance (\(\rho_{\lambda,h}\)) with blackbody emission at 298 K:  
\[\frac{\int_{0.3\upmu\mathrm{m}}^{17\upmu\mathrm{m}}(1-\rho_{\lambda,h})i_{ \lambda,bb}(\lambda,T_{a})d\lambda}{\int_{0.3\upmu\mathrm{m}}^{17\upmu\mathrm{m }}i_{\lambda,bb}(\lambda,T_{a})d\lambda}\]  
where \(i_{\lambda bb}(\lambda,T_{a})\) is the emission of a blackbody at ambient temperature. Thermal emittance at a defined temperature T (\(\varepsilon\)T) is the energy emitted by a material in comparison with the energy emitted by a blackbody at the same temperature and represents the ability of a material to lose energy by thermal radiation. Pavements with high emittance values will lose thermal energy faster than pavements with lower ones and they will reach lower temperatures by solar absorption. Albedo, or solar reflectance, is the percentage of solar energy reflected by a surface. Researchers have developed methods to determine solar reflectance by measuring how well a material reflects energy at each wavelength, then calculating the weighted average of these values. In order to calculate albedo, hemispherical reflectance of pavements is measured with a double-beam UV/VIS/NIR Perkin Elmer Lambda 950 Spectrophotometer, with a 10 cm integrating sphere coated with a diffusing material. The integrating sphere allows us to measure the amount of incident radiation on sample surface that is reflected in all directions. Four readings of each pavement sample were measured (300-2500 nm), and albedos of concrete pavements were calculated by averaging reflectance measurements with air mass 1.5 global solar radiation spectrum:  
\[Albedo=\frac{\int_{0.3\upmu\mathrm{m}}^{2.5\upmu\mathrm{m}}\rho_{\lambda}~{}G _{b}(\lambda)d\lambda}{\int_{0.3\upmu\mathrm{m}}^{2.5\upmu\mathrm{m}}G_{b}( \lambda)d\lambda} \tag{2}\]  
where \(\rho_{\lambda}\) is the hemispherical reflectance for each wavelength value and \(G_{b}(\lambda)\) is the spectral solar irradiance AM1.5G (ASTM G173-03).