## 4 Discussion  
There are many different factors that contribute to the challenge of estimating the amount of water that can be absorbed by FRAs. Particles with sizes ranging from 50 \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Size Range (mm)**} & \multicolumn{3}{c}{**Water Absorption (\%)**} \\ \cline{2-4}  & **NQ** & **RQ** & **RG** \\ \hline
4.75–2.36 & 3.6 & 6.2 & 6.9 \\
2.36–1.18 & 3.2 & 6.4 & 7.7 \\
1.18–0.6 & 3.8 & 6.2 & 8.6 \\
0.6–0.3 & 3.2 & 6.2 & 7.8 \\
0.3–0.15 & 3.8 & 9.2 & 10.8 \\ Weighted average & 3.6 & 6.8 & 8.0 \\
0.0–4.75 & 3.2 & 6.6 & 8.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Water absorption results for electrical method. Figure 6: Cumulative frequency of R\({}^{2}\) values. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Size Fraction (mm)**} & \multicolumn{2}{c}{**NQ**} & \multicolumn{2}{c}{**NQ**} & \multicolumn{2}{c}{**RG**} \\ \cline{2-7}  & **Dry** & **Wet** & **Dry** & **Wet** & **Dry** & **Wet** \\ \hline
0.0–4.75 & 0.487 & 0.0059 & 0.537 & 0.2108 & 0.507 & 0.097 \\
4.75–2.36 & 0.543 & 0.050 & 0.614 & 0.070 & 0.744 & 0.073 \\
2.36–1.18 & 0.504 & 0.026 & 0.718  
to 4000 \(\upmu\)m can have extremely varied characteristics in terms of their composition and shape. Both of these aspects can vary very significantly in such a wide range of sizes. The recycled aggregates that come from the waste concrete are materials that have more than one phase. Even if these materials could be processed and released of any impurities that may have been introduced during the process of recycling (e.g., soil, gypsum, wood, bricks, and asphalt), they would still be a combination of hydrated cement paste and natural rocks. Because the hydrated cement paste phase is the phase that causes an increase in the material's porosity and absorption capacity, we need to concentrate on that phase whenever we are conducting any kind of analysis regarding the representativeness of an experimental method for determining the water absorption capacity. The cement paste and the natural rocks do not differ only in porosity but also in strength. This is important to consider as the recycling process involves the crushing of the waste concrete and the division of the material into smaller particles by splitting it through the weakest planes. The mechanical effort of crushing is also combined with the self-abrasion between particles that clash with each other during rotatory processing. The soft cement paste particles would be more easily crushed, abrased, and concentrated in finer fractions. Such a difference in composition requires an account of the sensitivity of the conductivity method to the increase in paste content. To link both parameters, for the case of RG, the paste content according to ASTM C 1084 was determined for each sized fraction. The results are shown in Figure 7. Although the R\({}^{2}\) value is not excellent, a trend to increase the WA with the increase in paste content is suggested. The lack of adjustment is likely a consequence of other variables also affecting the WA value measured. For the same volume of solids, more angular shapes, more surface roughness, and a higher content of fines would allow for more solid-solid contact points. This would increase the number of menisci formed by surface water, and would potentially affect the conductivity of the granular skeleton [45]. No difference due to composition or particle size was observed among all the tested samples and sub-samples in terms of the linearity of wet and dry branches. This can be interpreted as the fact that the same phenomena are governing the correlation between electrical conductivity and moisture content in the granular skeletons. In other words, any change in particle shape, particle size, or composition does not translate into changes in the building up of conductive bridges as the moisture content increases.