Selection and Storage Requirements of Corrugated Metal Ducts

The prestressed corrugated duct should be selected according to the design requirements, generally composed of metal corrugated duct or plastic corrugated duct. For T-beams, small box beams, and cast-in-situ structures with a span greater than or equal to 25m, plastic corrugated ducts should be used; metal corrugated ducts should be used for hollow slabs with spans less than 25m. When pouring concrete into a post-tensioned prestressed concrete structure, the ducts in the concrete must not leak. The corrugated duct should meet the requirements of design strength, so that it can still maintain the original shape under the gravity effect of the concrete, and can transmit the bonding stress as required. The appearance of the prestressed ducts should be inspected before use. The internal and external surfaces should be clean, and free of rust, oil, holes, and irregular folds, and there should be no openings or tripping at the nozzle.