Introduction
Ministry of water resources and irrigation (MWRI) has many large concrete structures projects in the Nile River, irrigation network, and drainage network as new structures or replacement to old ones. Most of the concrete structures in these projects are water structures such as bridges, regulators, barrages, culvers, siphons and aqueducts. Some parts of the concrete of mentioned water structures are embedded in soil contaminated with chlorides and sulfates while, the other parts are exposed to irrigation water or drainage water (immersion in water) which is contaminated with salts.
The two most common causes of reinforcement corrosion are (i) localized breakdown of the passive film on the steel by chloride ions and (ii) general breakdown of passivity by neutralization of the concrete, predominantly by reaction with atmospheric carbon dioxide (Batis and Rakanta, 2005). Sound concrete is an ideal environment for steel, but the increased use of deicing salts and the increased concentration of carbon dioxide in modern environments principally due to industrial pollution, has resulted in corrosion of the rebar becoming the primary cause of failure of this material.
Introduction
Ministry of water resources and irrigation (MWRI) has many large concrete structures projects in the Nile River, irrigation network, and drainage network as new structures or replacement to old ones. Most of the concrete structures in these projects are water structures such as bridges, regulators, barrages, culvers, siphons and aqueducts. Some parts of the concrete of mentioned water structures are embedded in soil contaminated with chlorides and sulfates while, the other parts are exposed to irrigation water or drainage water (immersion in water) which is contaminated with salts.
The two most common causes of reinforcement corrosion are (i) localized breakdown of the passive film on the steel by chloride ions and (ii) general breakdown of passivity by neutralization of the concrete, predominantly by reaction with atmospheric carbon dioxide (Batis and Rakanta, 2005). Sound concrete is an ideal environment for steel, but the increased use of deicing salts and the increased concentration of carbon dioxide in modern environments principally due to industrial pollution, has resulted in corrosion of the rebar becoming the primary cause of failure of this material.
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