PSI - Issue 81

Bohdan Parneta et al. / Procedia Structural Integrity 81 (2026) 383–387

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capillary rise is less pronounced (Luchko et al., 1998; Mendes et al., 2014). Non-porous materials completely prevent both water penetration and capillary rise. The presence of dark stains on plaster, white efflorescence, surface flaking, and deterioration of concrete in a horizontal band at a certain height above ground level are characteristic indicators of the harmful effects of soluble salts (Li et al., 2024). Sources of salinization may include groundwater, leaking sewer networks, rainwater, as well as improper storage of salt-containing products in basements (Monczyński, 2024; Rybak et al., 2024). Moreover, salts can appear in concrete due to the use of low-quality building materials (Nazarevych, 1998; Parneta et al., 2024). The purpose of this paper is to evaluate the long-term effectiveness of horizontal injection waterproofing in structures made of concrete. For this purpose, changes in moisture content were observed in both dry and wetted areas of concrete samples. This allowed us to assess the actual effectiveness of the applied technology over a long period of operation. 2. Methods of experimental research To assess the long-term effectiveness of horizontal injection waterproofing within this study, concrete specimens that had participated in the previous experiment, shown in Fig. 1, were used. The investigation was conducted fourteen years after the installation of the injection waterproofing layer, which made it possible to evaluate changes in moisture content and chloride accumulation in the material over a prolonged exposure period.

Injection waterproofing line

Fig. 1. Specimens for testing.

Before the start of the measurements, the specimens were cleaned of surface salt deposits (Fig. 2a) and then placed in metal trays filled with a 20% NaCl solution (sodium chloride ) (Fig. 2b). The laboratory temperature was maintained at 16 °C, which corresponded to the conditions of the previous experiment and ensured comparability of the obtained data. Moisture content was evaluated in both dry and wetted zones of the specimens, on the surface and within the material. Internal moisture was measured using the carbide rapid method with a portable moisture-measuring station of the CCM-GERATE type. In the concrete specimens, holes with a diameter of 12 mm were drilled, and 50 g samples were taken for subsequent weighing on high-precision laboratory scales included in the moisture meter set.

Fig. 2. (a) Specimens cleaned of surface salt deposits; (b) Specimens immersed in metal trays with NaCl solution.