Investigation On The Diseases Of Highway Old Concrete Bridge And Carrying Capacity Evaluation

The normal use of highway concrete bridge will be influenced by diseases under the interaction and effect of both interior and exterior factors during its work-life. A detailed investigation and analysis has been carried out on the diseases of concrete bridge and the causes of defects of extant concrete bridge are environmental effect and load or improper design and construction. The diseases of bridge caused by environment are concrete carbonization, chloride ion erosion, freeze-thaw damage and corrosion of steel bar. In addition, the diseases of bridge caused by load or improper design and construction are lower bridge design load, unreasonable structure or construction reason.The author systematically summarized the reason of every kind of disease, the mechanism of diseases and the damage to the structure and prevention measures of every disease were given out. According to the bridge assessment method based upon analytic hierarchy process in Code for Maintenance of Highway Bridges and Culvers of our country, the disease investigation and the evaluation of bridge technique condition were carried out to obtain the distribution of bridge diseases and the health condition of bridge.The author evaluated the bearing capacity of a certain reinforced concrete simple T—beam based on the method of bridge static loading experiment and designs related experiment scheme site implemented. In conclusion, the whole bearing capacity of bridge could not meet the requirement of design load, so the strengthening design of this bridge was carried out.