Title:
Behavior and Protection of Hydrogen Embrittlement on Tendons of PC Members
Author(s):
K. Ikawa, K. Ishii, T. Fukute, and H. Seki
Publication:
Symposium Paper
Volume:
163
Issue:
Appears on pages(s):
255-274
Keywords:
cathodic protection; hydrogen; PC physical tests; prestressing steels; seawater; Materials Research
DOI:
10.14359/1362
Date:
8/1/1996
Abstract:
Presents the results of a study on hydrogen embrittlement of prestressed concrete (PC) tendons. The purpose of this research work was to make clear the influence of cathodic protection used in PC members. The tests consisted of three series. Series A was carried out to evaluate the relationship between the polarization potential and the period of current supply. In Series B, a countermeasure to mitigate hydrogen embrittlement was investigated. PC members in Series C were cathodically protected and exposed to a sea environment for five years. Cathodic polarization was applied to the wire specimens of Series A under tension stress. After polarization, the wires were soaked in a saturated solution of Ca(OH) 2; slow strain ratio test (SSRT) was carried out. In Series B, polarization was applied to wires under tension stress and were then kept under no current supply for 15 hr to five days. Finally, mechanical properties were evaluated. After exposure of five years to a sea environment, PC tendons were taken out of the Series C concrete specimens; SSRT and tests of hydrogen occlusion were carried out. This test program showed that the harmful effects of hydrogen embrittlement may be mitigated by switching off of the cathodic protection at regular periods.