## 3 Results
### Characterization of CDW
However, such addition of water can led to mortar expansion which, when exposed to the sun, will lead to water loss through elevated drying by shrinkage and cracking [45]. Figure 2: Cumulative underflow distribution of different CDW granulometries and normal upper and lower limits for concrete production. Curves found for CDW residue swelling present a similar behavior to those found by [PERSON] [45], where there was a small decrease in volume at 10% moisture ([PERSON] found 16%). This behavior was probably due to a lubrication effect between the fine particles of the aggregate and a water film for this given water addition [45]. Swelling values for coarse, medium, and fine aggregates were 22%, 25%, and 28%, respectively ([PERSON] [45] found 48%). The aggregate swelling test indicates that the recycled aggregate has a higher critical moisture for the same swelling coefficient. The results listed in Table 2 show the X-ray fluorescence for different CDW residues granulometries obtained from quantitative analysis and accomplished via molten sample technique with calibration curves from rock standards. Values are shown as a percentage of sample weight; Nd means \"not detected\" by the method. Loss on ignition (volatile presence) was evaluated through gravimetric techniques and is indicated as LOI. The analysis of XRF for CDW residue shows that the higher concentrations are related to SiO\({}_{2}\), 73.05% to 78.38%, which has an origin associated with natural aggregates of concrete and mortar, and CaO, 6.53% to 8.43%, which is associated with binders. XRF results also indicate Mg and Ca, which can be present as carbonates. If Mg and Ca are in oxide shape, the presence of CaO and MgO in the concrete can be dangerous, since they can induce pathologies over time (expansions). Al\({}_{2}\)O\({}_{3}\) is also present in concentrations varying from 3.39% to 4.83% from the presence of red ceramics and soil and, secondly, due to the presence of feldspar and cement in the CDW residue. A mean SO\({}_{4}\) concentration of 0.94% is possibly due to the presence of plaster in the residue [46]. This percentage is below the amount of plaster found in residues from this region analyzed in former studies (around 2.4%) [10]. The amount of K\({}_{2}\)O found in the residue can induce an alkali-silica reaction in the concrete. \begin{table}
\begin{tabular}{l|l l l} \hline \multirow{2}{*}{**Oxides**} & \multicolumn{3}{c}{**CDWs Residue Granulometry**} \\ \cline{2-4}  & **Fine** & **Medium** & **Coarse** \\ \hline SiO\({}_{2}\) & 78.38 & 77.75 & 73.05 \\ Al\({}_{2}\)O\({}_{3}\) & 3.39 & 3.74 & 4.83 \\ TiO\({}_{2}\) & 0.24 & 0.23 & 0.35 \\ Fe\({}_{2}\)O\({}_{3}\) & 1.30 & 1.39 & 1.96 \\ MnO & 0.06 & 0.05 & 0.06 \\ MgO & 1.23 & 1.23 & 1.38 \\ CaO & 6.53 & 6.72 & 8.43 \\ Na\({}_{2}\)O & Nd & Nd & Nd \\ K\({}_{2}\)O & 0.84 & 0.93 & 1.15 \\ P\({}_{2}\)O\({}_{6}\) & 0.06 & 0.04 & 0.06 \\ SO\({}_{4}\) & 1.02 & 0.79 & 1.02 \\ LOI & 6.96 & 7.13 & 7.71 \\ Total & 100.0 & 100.0 & 100.0 \\ \hline \end{tabular}
\end{table} 
Table 2: X-ray fluorescence (XRF) chemical analysis for CDW. Figure 3: Swelling coefficient as a function of moisture content for CDW classified as **(a)** coarse; **(b)** medium; and **(c)** fine. The variation in CDW granulometry influences the amount of SiO\({}_{2}\); that is, the CDW with fine granulometry has a greater amount of SiO\({}_{2}\) than medium CDW and is, in turn, greater than coarse CDW. The loss on ignition (LOI) varied from 6.96% to 7.71%, and was essentially related to the loss of volatiles by the release of combined water and carbon dioxide from hydrated calcium silicates and hydrated lime and carbonates. It was also related to water released from phyllosilicates present in soil, ceramics burnt bellow 500 \({}^{\circ}\)C, and other minor minerals present in coarse natural aggregates (gravel obtained from rocks such as granite) [46; 47]. Another observation is that increases in CaO (%) ultimately related to the amount of CaCO\({}_{3}\) will increase LOI values, since CaCO\({}_{3}\) yields CaO + CO\({}_{2}\).