Title:
Assessment of Threshold Chloride of RC Structures in Hot Tropical Climate (Prepublished)
Author(s):
Mshtaq Ahmed, Abdulrahman Alhozaimy, Abdulaziz Al-Negheimish, and Raja Rizwan Hussain
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
chloride threshold value; concrete; corrosion potential; corrosion rate; mass loss; microstructure; steel reinforcing bars, sustainability; temperature
DOI:
10.14359/51744379
Date:
11/22/2024
Abstract:
Chloride threshold values for steel rebars in reinforced concrete under the effect of varying temperatures and extended long-term conditions in hot climates 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 rebars sourced from two manufacturers were cast with different chloride contents and exposed to four temperatures of 20, 35, 50, and 65ºC (68, 95, 122, and 149ºF) 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 65ºC, respectively. These findings are significant as they showed a dramatic drop in the chloride threshold values at high temperatures. This research highlights the need for reassessment of ACI code limits considering the hot climate.