PSI - Issue 64

Pascual Saura Gómez et al. / Procedia Structural Integrity 64 (2024) 2125–2132 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

2131

7

10.00

10.00

uncracked cracked

middle end

1.00

1.00

2 )

2 )

0.10 I corr (µA/cm

0.10 I corr (µA/cm

0.01

0.01

10

100

1000

10

100

1000

a b Fig. 8 Relationships between I corr and resistivity ρ measured (a) in uncracked and cracked zones, (b) in the middle and at the ends of the beam. ρ ( K Ω cm) ρ ( K Ω cm)

-700 -600 -500 -400 -300 -200 -100 0

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00

uncracked cracked mean

E corr (mV Cu / CuSO4 )

Cl - (% cem.)

uncracked cracked mean

0.0

0.5

1.0

1.5

2.0

0.0

0.5

1.0

1.5

2.0

a

b

crack width (mm)

crack width (mm)

Fig. 9 Influence of crack opening on: (a) chloride content, (b) corrosion potential.

10.00

400

uncracked cracked mean

uncracked cracked mean

300

1.00

2 )

200

ρ ( K Ω cm )

I corr (µA/cm

0.10

100

0

0.01

0.0

0.5

1.0

1.5

2.0

0.0

0.5

1.0

1.5

2.0

a

b

crack width (mm)

crack width (mm)

Fig. 10 Influence of crack opening on: (a) resistivity, (b) corrosion rate.

5. Conclusions This study aims to investigate the dependency of corrosion measurements on cracking in PC beams exposed to an industrial water environment containing chlorides (from the sea water) for over ten years. During the service life, the corrosion propagation was caused by a significant presence of chlorides (2-5% by weight of cement), which is much higher than the thresholds of the standard for prestressing steel (0.3 % by weight of cement). The observations are: • The presence of cracks increases the chloride content at the level of the reinforcement. Indeed, the crack is identified as a preferential path for aggressive agents to enter. • Consistently with the chloride content values, the corrosion-related parameters indicate an active state of corrosion in strands; in particular, in cracked zones of the beams, the values of corrosion potential tend to be lower, the values of the corrosion rate tend to be higher, and the values of the resistivity tend to be lower than in the uncracked zones.