PSI - Issue 73

Miroslav Vacek et al. / Procedia Structural Integrity 73 (2025) 146–154 Miroslav Vacek, V´ıt Krˇivy´, Barbora Krˇistkova´ / Structural Integrity Procedia 00 (2025) 000–000 Table 1: Distance and height of the stands from the road

149

4

Stand

1

2

3

4

5

6

Distance from the road (m)

17 11

16 10

15 10

9 7

6 5

2 2

Height of the stand from the road (m)

Height of the noise barrier (m)

3

3

5 + 2 (45°)

5 + 2 (45°)

5 + 2 (45°)

5 + 2 (45°)

Each wet candle is prepared as 200 ml of glycerol solution, prepared in accordance with ISO 9225 (27). The stock solution consisted of 200 ml of glycerol diluted to 1 liter with deionized water, along with 20 drops of caprylic acid to prevent fungal growth. The exposed part of the wick of the wet candle is made of a PPR tube wrapped in a crepe bandage. The area of the exposed part of the wick is 100 cm 2 . After exposure of the wet candle, the solution is diluted inside the bottle from approximately 200 ml with deion ized water to 250 ml. The amount of chloride ions collected by the wet candle is measured using the Hach Pocket Colorimeter ™ II (28) and the Hach LCK311 chloride cuvette test (29). Both can be seen in Figure 4.

Figure 4: Hach Pocket Colorimeter ™ II and LCK311 chloride cuvette test

The amount of chloride ions within the wet candle solution is calculated using the Equation 1, which is from the ISO 9225 (27). The average monthly deposition of chloride ions is impossible to determine when a wet candle is damaged or lost or when the measurement is determined as the background value (the chloride concentration is below the resolution of the Hach Pocket Colorimeter ™ II (28)).

m 1 − m 0 A · t

(1)

S d , c , i =

where

• S d , c , i - average monthly deposition of chloride ions measured by the wet candle method on stand ”i”(mg / (m 2 · day)); • m 1 - mass of chloride ions in the solution after the exposition in the 1 liter volume (mg); • m 1 - mass of chloride ions in the solution before the exposition in the 1 liter volume (mg);

• A - exposed area (m 2 ); • t - exposure time (days).

To compare chloride ion deposition on the obverse and reverse surfaces, it is essential to use matching measurement data from both sides for each exposure period. The deposition ratio is calculated whenever valid data from both