Method for exhausting arch rib air in process of pouring concrete in arch bridge steel pipe

Abstract

The invention relates to a method for exhausting arch rib air in the process of pouring concrete in an arch bridge steel pipe. The method comprises the following steps: step 1, arranging a plurality of exhaust holes on a steel pipe adjacent to the vault of an arch rib, closing all the exhaust holes, pouring concrete into the arch rib in a vacuumizing manner until qualified concrete is discharged from a grout outlet of the vault, and then stopping pumping of the concrete; step 2, opening at least one exhaust hole, inserting a vibrating rod for vibrating, and closing the exhaust hole until no gas or thick slurry emerges from the exhaust hole; step 3, repeating the step 2, and vibrating and exhausting the other exhaust holes in batches until all the exhaust holes finish vibrating and exhausting; and step 4, after completion of vibrating and exhausting in the step 3, keeping the concrete at the vault grout outlet to the original liquid level height, closing the vault grout outlet, and completing arch rib air exhausting. According to the method, air in the steel pipe near the vault can be effectively exhausted, a phenomenon that the steel pipe is disengaged after concrete pouring is completed is avoided, and operation is convenient.

Description

technical field [0001] This field relates to the technical field of steel pipe concrete arch bridge construction, in particular to a method for discharging air from arch ribs during pouring of steel pipe concrete arch bridges. Background technique [0002] Concrete pouring for arch ribs of CFST arch bridges is one of the most critical processes in the construction of CFST arch bridges, and its quality also directly affects the quality of completed bridges, which is related to the operation safety of the bridge. [0003] At present, during the pouring construction process, the air pressure in the pipe is pumped to a negative pressure with a vault vacuum pump, and this negative pressure is maintained until the entire pipe is poured. Through this measure, the moisture in the air in the pipe and the air bubbles generated in the concrete can be pumped away. Greatly reduce the emptying of concrete filled steel tubes caused by air bubbles and moisture accumulation. However, for th...

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Problems solved by technology

However, for the vault and its nearby pipe joints, since the pipe joints tend to be horizontal, it is difficult to vacuum the air bubbles accumulated at the top surface of the steel pipe section near the vault, resulting in The gap between the steel pipe and the concrete will affect the pouring quality of the concrete in the pipe, and seriously affect the bearing capacity of the steel pipe concrete. A large number of engineering practices have shown that the steel pipe concrete often has debonding phenomenon, and the maximum value of the debonding gap d is generally 1~ 3mm, and increases with the construction time

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