Abstract
NT Build 492 regulates that the pressure be set at 7.5–37.5 torr and be maintained for 3 h for vacuum processing. This large range of acceptable vacuum pressure is awkward for research, and 3 h of pump-down time may be excessive. In this study, vacuum conditions were divided into vacuum pressure and pump-down time groups: various vacuum pressures and pump-down times were used to preprocess specimens to explore the effect of vacuum conditions on the RCM test. The salt ponding test was also conducted to identify the optimal vacuum conditions. It is shown that the relationship between vacuum pressure and the migration coefficient approximates an exponential function with vacuum pressure group. Moreover, the vacuum pressure should be lower than 7.5 torr to obtain accurate results from RCM test. For pump-down time group, using a vacuum pressure of 2 torr can shorten the pump-down time to 1 h and improve the test efficiency; vacuum pressures of 30 torr should not be used. Finally, this study indicates the most suitable vacuum conditions for RCM test by establishing relationship between diffusion and migration coefficients: 1–2 torr of vacuum pressure and 1 h of pump-down time.
Recommended Citation
Lin, Chih-Yen; Chang, Chun-Fu; and Yang, Chung-Chia
(2023)
"Influence Of Vacuum Condition On Rapid Chloride Migration (Rcm) Test For Chloride Penetration Resistance Of Concrete,"
Journal of Marine Science and Technology: Vol. 31:
Iss.
1, Article 5.
DOI: 10.51400/2709-6998.2684
Available at:
https://jmstt.ntou.edu.tw/journal/vol31/iss1/5
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