| Title |
Bond Strength of Corroded Bars Embedded in Reinforced Concrete Slab |
| Keywords |
Reinforced Concrete ; Slab ; Anchorage length ; Corrosion ; Bond strength |
| Abstract |
Concrete normally provides reinforcing steel with excellent corrosion protection. The high alkaline environment in concrete results in the formation of tight adhering film on the reinforcing bars which passivates the steel and protects it from corrosion. Corrosion of steel, however, can occur if the water, oxygen and salt ions such as chloride ion penetrate to the surface of steel through the cracks in concrete. And also corrosion can be proceeded in the case of carbonation of concrete. The deterioration of reinforced concrete quality by those corrosions raised a severe problem in the durability of reinforced concrete structure.
This research is aimed at providing the data for design methods of repair and rehabilitation of reinforced concrete structure, which is damaged by the deterioration of concrete quality and bond strength deterioration due to corrosion.
Experimental test was performed for the variables such as corrosion rate, thickness of cover concrete and development length of reinforcement.
Based on the experimental work, following conclusions were drawn
1. When the mass loss is less than 2%, bond strength of rebar is increased.
2. When the mass loss is less than approximately 3%, resisting force is not reduced because most corrosion is occurred on the surface of rib.
3. When the mass loss is more than approximately 5%, resisting force is rapidly reduced with increasement of corrosion level.
4. For deformed bar or deformed wire in flexural tension, following equation of development length in Eg 8.2.2 in Korean Concrete Structural Design code is suggested, |