Causes of Crack and Durability Analysis of Corroded Reinforcing Bars in Three-Orientation Pre-stressed Aqueduct with Long-span at Cold Areas

Abstract

A large aqueduct located in the cold region of north China adopts three-orientation pre-stressed reinforced concrete structure with large span. During the construction period, after the third spring, the quality inspection of the aqueduct wall has a phenomenon of vertical long cracks, white paste, alkali corrosion and water seepage, and there is also an empty drum sound inside the wall. Using theoretical solution and numerical calculation method, the causes of cracks on the surface and the internal hollow of the aqueduct wall are analysed from the aspects of pre-stressed tension, frost heave and ambient temperature. A nonlinear finite element model with fine mesh is established to simulate the initiation of the crack and penetration process through the single hole and multiple holes frost heaving process of the bellows. Finally, the durability and hazard of aqueduct are evaluated by calculating the influence of different seam depths on the pre-stressed steel bars and ordinary steel corrosion, which provides a basis for the later crack repair protection scheme, and also provides reference for the construction and operation management of such aqueducts.