The Study of Concrete Durability in the Case of Jinan Yellow River Highway Bridge
Examensarbete för masterexamen
Infrastructure and environmental engineering (MPIEE), MSc
Reinforced concrete has been commonly used in China as the most popular structural material in many infrastructures. However, since these structures have served for several decades, problems of concrete durability gradually arise due to severe service environment or air pollution of increasing CO2 concentration. The durability of the reinforced concrete structures principally depends on the optimization of five factors. They are structure design, construction operation, management and maintenance, material properties and the external environmental conditions. These five factors are closely correlated with each other so that the durability will be markedly reduced if one of them is poor. Without adequate durability, the reinforced concrete structure may deteriorate either due to concrete damages or due to reinforcement corrosion. The main reasons behind are concrete carbonation, chloride ion ingress, alkali-aggregate reactions and freeze-thaw cycles. In this study the influences of five factors on the concrete durability were analysed. Further investigation was made regarding the deterioration of reinforced concrete. As a case study Jinan Yellow River Highway Bridge was inspected in the aspect of concrete durability. The result shows that most of the chambers inspected in Jinan Yellow River Highway Bridge are in a good condition. Concrete suffers slightly from carbonation but the thickness of carbonation depth is far less than the concrete cover. The reinforcement is not likely to be corroded. However, in some testing chambers there are problems with inadequate thickness of concrete cover and cracks. These problems can be treated by pasting cement mortar, which is for safety consideration.
Building Futures , Byggnadsteknik , Building Futures , Building engineering