3.2.2. Determination of Tensile Strength in Flexion and Compression

Table 14 presents the compressive strengths found in the mortars made with Portland cement types CP II, CP III and CP V, with curing of 7, 14 and 28 days, in the different replacement of sand by OSPW (10%, 30% and 60%).


**Table 14.** Flexural and compression strength test results.

<sup>1</sup> FS—flexural strength; <sup>2</sup> SD—standard deviation; <sup>3</sup> CS—compression strength.

Analyzing the compressive strength of mortars, it was found that in all three types of cement, the highest strengths were found in the replacement of 30% of OSPW, and these values were identified in CP III and CP V cements, at 28 days of curing, and in cement CP II, at 7 days of curing.

In Portland cement type CP II, the highest strength found was 9.82 MPa tested at 7 days of curing, in the percentage of 30% replacement, while the lowest strength was 3.83 MPa tested at 14 days of curing, in the 10% replacement percentage. Note that the strengths of the mortars tested at 7 and 28 days of curing present similar values in all replacements.

In mortars made with CP III type cement, the highest strengths, in all percentages, were at 28 days of curing, with the highest value being 8.82 MPa in 30% replacement. On the other hand, the lowest resistances found, regardless of residue replacements, were at 14 days of curing.

In Portland cement type CP V, the highest strengths, as well as in CP III, were at 28 days of curing, regardless of percentages, with the highest value of 12.56 MPa in 30% replacement. While the lowest resistances were at 7 days of curing in all percentages.

Table 14 also shows the flexural tensile strengths found in mortars made with Portland cement types CP II, CP III and CP V, with cures of 7, 14 and 28 days of curing, in the different replacements of sand by OSPW (10%, 30% and 60%).

Analyzing the flexural tensile strengths of mortars, it was found that in all three types of cement, the highest strengths were found in the replacement of 30% of OSPW, at 28 days of curing, with the highest value being 3, 12 MPa, found in CP V cement. In Portland cement type CP II, the mortars tested at 7 and 14 days of curing showed similar strengths, while those tested at 28 days showed greater discrepancies.

The mortars made with cement type CP III tested at 28 days showed higher strengths in all replacement percentages, when compared to the other curing times of the same cement. In contrast, the lowest resistance found was with 60% replacement tested at 14 days of curing. In Portland cement type CP V, the mortars tested at 28 days showed the highest strengths with 10% and 30% replacement, however, with 60% the mortars that showed higher values were those tested at 14 days of curing.
