Prestressed plastic bellows is HDPE as raw material, is a new material into the hole. Post-tensioned concrete structure applied to the important, the rod into the hole, with good sealing, no water seepage drain paddle, ring stiffness, low friction parameters, anti-aging, anti-electric erosion, soft elastic good, can not easily be broken tamper chisel and new ways to make connection easier construction joins strengths. After being tarnished as a porous material, paddle body is prestressed concrete structures prestressed steel last protective barrier. Prestressed plastic bellows material is HDPE. It is far superior to metal corrosion resistance, not afraid of acid, alkali corrosion, which itself does not corrode, can effectively protect tendons from corrosion. Many of prestressed structures suffer serious impact outside, such as de-icing salt or brine. When the tension members due to the collapse of the waterproof layer, micro-cracks and leaking drainage obstruction or failure, tendons will likely suffer corrosion. "FIP Construction Guide (1990)" in "grouting tendons" that no permanent metal pipe corrosion resistance, enough to resist water leakage and reach slurry and tendons. The prestressed corrugated plastic pipe can provide a far superior barrier protection metal bellows for tendons, to prevent contamination of harmful substances through the pipeline, thus ensuring the post-tensioned structure has better durability .