Research On Health Monitoring Of Electrically Isolated Post-Tensioning Tendons

Prestressing technology had been widely used, especially in Large-Span Housestructure and bridge structure in various fields in civil engineering nowdays. In theearly1982, the Americans named Morris Schupack presented the electrical insulationassembly method. In2005, the completely encapsulated electrical insulationanchoring system (EIT) presented by fib (International Association of StructuralConcrete) was subjected to the attention of the designers in our country and abroad. In2007, the specification of the design and construction of prestressed anchor system ofelectrical insulation was made by Switzerland’s traffic management department of theSwiss Guideline.The anchoring principle of electrical insulation was introduced on the necessity ofanchoring system for electrical insulation in prestressed structures in this paper. Theconnect optimization design between the plastic horn duct and the anchoring Platewas presented on the basis of the master’s degree thesis written by Liu Pingwei andthe research of Liuzhou OVM company. A new type horn duct was designed in orderto enhance the leakproofness of the electrical insulation anchors. In combine of thePL3system presented by the International Concrete Association (fib), monitor thepost-tensioned concrete tendons by getting through the nondestructive testing method,research the relationship of resistance value or capacitance value of prestressingtendons and the health condition, and the relationship of the healthy condition and themonitoring date was discuss by the accelerated corrosion test.In this paper, based on the anchoring system of the outcome of electricalinsulation of Liuzhou OVM Machinery Co., Ltd. and the master’s degree thesiswritten by Liu Pingwei, the main research work are as follows:(1) Analysis the structural durability monitoring status quo all the world, studythe basic principles and conclusions of the latest electrical insulation anchoringsystem on aboard. Present the new method of electrical insulation anchoring system.(2) Research the foreign electrical insulation anchor and Liuzhou OVManchorage, present the better plastic horn tube with the tightness of the connection ofthe anchor plate more favorable by the basis of safety, economy and insulation.(3) Study the feasibility of alternative to the traditional overall pouring cast ironanchor plate for high-performance concrete with cast iron anchor core. Force analysiswas made by the finite element software ANSYS structural stress analysis, and the actual load test was proceeded to verify the conclusions of the finite element.(4)A3meters’ prestressed test beam was poured in the laboratory, embedded fourPL3system of channels and anchoring system for electrical insulation systems. Studythe relationship of the health condition and the monitoring date by monitoring theresistance and capacitance for nearly six months. Study the change of monitoring dateby corrosion for the accelerated corrosion test on channel.