A study on cost effectiveness of HDPE sheathing for post-tensioned prestressed concrete structures over galvanised metallic ducts: Part Ⅰ (Round duct)

摘要

The main benefit of using HDPE ducts in prestressing system is the enhancement in the durability of the prestressed concrete structure. It renders the excellent protection of the prestressing steel, the most important element contributing to the safety of the structure against the corrosion. The users may get this benefit at more of less the same cost of conventional metal sheathings. Due to the lesser value of friction and wobble co-coefficients, the HDPE sheathing offers overall economy in prestressing system. This was an attempt made to quantify and bring out this advantage with the help of few case studies. This would give rough idea to the user about the possible saving in overall cost of the structure. The cost benefit increases with span of the girder. In addition to cost benefit, other advantages are user and friendly (i.e. easy to handle and joining), high durability etc. This, indeed, makes HDPE corrugated sheathing an ideal material in prestressing industry.