Under the patronage of the President of the Northern Technical University, Prof. Dr. Jassim Fathi Ali Al-Maadhidi, and under the supervision of the Dean of Mosul Polytechnic College, Asst. Prof. Dr. Abdul-Nasser Abdul-Razzaq Kashmoula, the Department of Building & Architectural Design Engineering Technologies organized a scientific symposium titled “The Effect of Concrete Admixtures on Rebar.”
The symposium was presented by Asst. Lect. Shaker Ahmed Khudair.
Topics Covered: The symposium addressed the effect of concrete admixtures on reinforcing steel, their role in improving the bond strength between concrete and rebar, and maintaining the passive protective layer that shields steel from corrosion. It also emphasized the importance of selecting appropriate admixtures in accordance with approved technical specifications.
Objectives:
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To clarify the impact of concrete admixtures on the properties of concrete and rebar.
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To demonstrate the role of admixtures in enhancing the bond between concrete and reinforcing bars.
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To introduce mechanisms for mitigating rebar corrosion and extending the service life of concrete structures.
Key Recommendations:
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Avoid Chlorides: Refrain from using hardening accelerators containing calcium chloride in reinforced concrete due to the increased risk of rebar corrosion.
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Use Corrosion Inhibitors: Adopt corrosion-inhibiting admixtures when necessary, particularly in structures exposed to harsh environments.
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Reduce Permeability: Incorporate mineral admixtures, such as silica fume and slag, based on a well-designed mix to lower concrete permeability and restrict the ingress of moisture and salts to the rebar, while maintaining concrete alkalinity.
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Control Dosage: Adhere to specified admixture dosages and conduct trial mixes to verify performance and reduce bleeding, which can compromise concrete quality and its bond with rebar.
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Ensure Specification Compliance: Verify that chemical admixtures comply with approved standard specifications and confirm their suitability for reinforced concrete prior to use.