PSI - Issue 74

Maciej Gruszczyński et al. / Procedia Structural Integrity 74 (2025) 25 – 32 Maciej Gruszczyński / Structural Integrity Procedia 00 (2025) 000–000

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Fig. 3. View of the prepared samples; (a) a molded sample 100 × 100 × 10 mm in a mold made of stainless steel; (b) a sample taken out of the mold; (c) general view of the samples (on the left – reference mortar, on the right - samples based on cement with 4% addition of activated carbon). After carbonation was completed, the samples (both the series with and without activated carbon) were placed in a chamber filled with a mixture of gases: 1 ppm NO 2 and 2 ppm NO in nitrogen for 24 hours. The gas mixture was moistened with a saturator until the relative humidity was 60%. After this time, the samples were removed from the chamber and dried to constant weight. Tests consisting in the assessment of the concentration of nitrates and nitrites in the solutions leached from the mortar samples were carried out in order to determine the NO x adsorption. For this purpose, the samples were weighed in the ratio 1:5, i.e. 30 g of the sample and 150 g of water, and then shaken for 2 hours on a shaker . They were then centrifuged for 5 minutes at 4000 rpm. Electrical conductivity was measured and finally the concentration of nitrates and nitrites was determined chromatographically. 3. Results and discussion The results of the concentration of nitrates and nitrites in the solutions leached from the mortar samples (100 × 100 × 10 mm) are presented in Table 1.