考慮鋼筋腐蝕危害度之混凝土保護層厚度設計－－以臺灣沿岸地區為例

A Design Method for the Thickness of Concrete Cover Considering the Hazard of Steel Corrosion -Take the Coastal Zones in Taiwan for an Example

This study measured the air-borne chloride content in coastal regions of Taiwan, and incorporated the deterioration model of chloride ingress to construct an evaluation method with a view to estimate the corrosion of reinforcing steel bars. The results of this research would serve as references for engineers to modify properties of reinforcing steel bars when retrofitting the deteriorated reinforced concrete buildings. This study also proposed a procedure to calculate the corrosion degree of reinforcing steel bars under uncertain factors such as environmental conditions, material properties, and model errors. Based on the corrosion degree of reinforcing steel bars in environments where the buildings are located, designers can set allowable reliability to ensure required durability and determine the thickness of the concrete cover of structural members in buildings. Finally, this study suggested the thickness for the concrete cover of buildings with a service life of 40 years in Suao, Taichung, Kaohsiung, and Hualien, and compared them with the values recommended in the current specifications in order to know the reliability of durability.