Title:
Assessment of Threshold Chloride of Reinforced Concrete Structures in Hot Tropical Climate
Author(s):
Mshtaq Ahmed, Abdulrahman Alhozaimy, Abdulaziz Al-Negheimish, and Raja Rizwan Hussain
Publication:
Materials Journal
Volume:
122
Issue:
1
Appears on pages(s):
65-80
Keywords:
chloride threshold (CT) value; corrosion potential; corrosion rate; mass loss; microstructure; steel reinforcing bars, sustainability; temperature
DOI:
10.14359/51744379
Date:
1/1/2025
Abstract:
Chloride threshold values for steel reinforcing bars in reinforced
concrete under the effect of varying temperatures and extended
long-term conditions in hot climate are investigated. This investigation covers a gap in the current codes, including ACI 318,
where the effect of temperature on the chloride threshold is not
addressed. A total of 96 concrete specimens reinforced with carbon
steel reinforcing bars sourced from two manufacturers were cast
with different chloride contents and exposed to four temperatures
of 20, 35, 50, and 65°C (68, 95, 122, and 149°F) for a period of
more than 2 years. The chloride threshold values were determined
based on corrosion potential, corrosion rate, and mass loss at the
end of the exposure period. The results of the three techniques
showed a consistent trend of significant dependency of the chloride
threshold value on temperature. The average water-soluble chloride
threshold values based on mass loss were found to be 0.77%,
0.72%, 0.47%, and 0.12% by weight of cement for temperatures
of 20, 35, 50, and 65°C (68, 95, 122, and 149°F), respectively.
These findings are significant as they showed a dramatic drop in
the chloride threshold values at high temperature. This research
highlights the need for reassessment of ACI Code limits considering
hot climate.