## 3 Results  
### Characterization of CDW  
CDW residue was characterized for granulometry, specific mass, swelling, and by X-ray fluorescence, loss on ignition, and image visual analysis. Figure 1a-c show the CDW fine, medium, and coarse granulometry, respectively. The presence of different materials such as wood, Styrofoam, glass, concrete, brick, and paint among others can be observed. These materials are characteristic of CDW residues and, according to some authors, can influence concrete properties. The amount of wood can increase WA and decrease CS [40]. The addition of Styrofoam to the concrete can reduce its density, and consequently decrease CS as well as improve its thermal conductivity [41; 42]. The addition of glass residues to the concrete can induce an alkali-silica expansive reaction that occurs between the alkali in the cement and the silica in the glass, causing serious problems of cracking that compromise concrete durability. However, glass particle sizes smaller than 100 \(\upmu\)m do not react with silica, so concrete durability is assured [43]. Figure 1: Construction and demolition waste (CDW) granulometry (**a**) fine; (**b**) medium; and (**c**) coarse. The graph in Figure 2 shows the distribution of accumulated undersized CDW aggregates as a function of average particle diameter. It can be observed that approximately 95% of the CDW classified as coarse has aggregates with a diameter between 4.75 and 1.2 mm, 4.5% are between 1.2 and 0.6 mm, and 0.5% are smaller than 0.6 mm. With respect to CDW classified as medium, approximately 10% of the aggregates have a diameter between 4.75 and 1.2 mm, 46% are between 1.2 and 0.6 mm, and 44% are smaller than 0.6 mm. As for the CDW classified as fine, approximately 99% of its aggregates have a diameter smaller than 0.6 mm, and 1% between 1.2 and 0.6 mm. The fineness modulus for coarse, medium, and fine CDW granulometry were found to be respectively 3.4, 2.44, and 2.24; and maximum diameters were 4.75 mm, 1.18 mm, and 0.6 mm. The fineness modulus values obtained for CDW granulometries are in accordance with the limits established by Brazilian standard NBR 7211 [44]. Figure 2 also shows the upper and lower limits of fine aggregate distribution for concrete production following the NBR 7211 [44] standard method. According to these limits, it can be seen that the medium granulometry curve is contained within the usual ranges, the fine CDW distribution is found to be practically at the lower limit, and the coarse distribution is found above the upper limit of natural fine aggregates used in concrete production. The specific mass was determined via [PERSON]'s test. For coarse CDW granulometry, the specific mass was found to be 2450 kg/m\({}^{3}\) and 1 cm\({}^{3}\) of floated material; for medium granulometry, the specific mass was found to be 2430 kg/m\({}^{3}\) and 4 cm\({}^{3}\) of floated material; and fine granulometry showed a specific mass of 2420 kg/m\({}^{3}\) and 1 cm\({}^{3}\) of floated material. The results showed little specific mass differences between different CDW granulometries. These results are in agreement with former studies run by [PERSON] (2005). Considering that fine grained aggregates have high water retention capacity, it is important to consider swelling due to WA during concrete production for particle size distribution whenever added in terms of volume. According to NBR 6467 [33] Brazilian standard, the swelling can vary from 20% to 40%. For this, the swelling coefficient (ratio between wet and dry volumes) and critical moisture for different CDW granulometry was determined. Figure 3 shows swelling as a function of moisture content; the critical moisture values for coarse, medium, and fine granulometry fractions were 7.3%, 7.8%, and 9%, respectively. These results indicate that the amount of water absorbed by CDW residue caused an increase in volume. Also, fine granulometry CDW residue needs a greater amount of water to obtain the same swelling volume as medium and coarse granulometries.