The Research On The Testing Technology Of The Portrait Prestress Tension And The Bellows Grouting Compactness Of The PC Box Girder Bridge

In recent years, with diversification of bridge structure and increase of bridge span, prestressed concrete structure is widely used in bridge engineering and its requirements are gradually improving. As the most important part in prestressed structure, tensile force of longitudinal prestressed reinforcement is directly related to structure’s performance. Large tensile force makes concentrated stress in seat position increase rapidly and increase inverted arch value in beam and difficulty of pavement and construction of bridge deck. If the tensile force is too small, it can not meet the normal working demand of structure. The inner reinforcement of prestressedreinforcement is in a valid range has a relationship with Corrugated pipe duck compacting grouting.The corrugated pipe duck not compacted grouting will not be able to provide timely and effective protection for prestressed reinforcement, accelerating aging, cracking. Therefore,the longitudinal prestressed reinforcement and the corrugated pipe duck compacted grouting are the key to assessing prestressed components performance.All in all,the research is focused on the assessment of existing bridges’longitudinal prestressed and the detection of Duct Grouting compactness. The main work is as follows:1) For the research focus of this paper, the author elaborates from the research purpose, current research, engineering background and other aspects respectively;2) Effective prestress and prestressed loss are described in detail, the feasibility of the prestressing loss formula law is discussed and future research directions is proposed;3) For the detection of longitudinal prestressed, the paper researches in non-destructive test and destructive test and innovates on the basis of original pull-off method.Through these two methods, mainly on numerical analysis, test system research and development and test have breakthrough and innovation.4) It has a brief introduction of ultrasonic propagation characteristics within the solid medium. Through Abaqus finite element software simulating propagation of acoustic waves in the concrete of the inner member, the paper guides model test and follow-up researches;5) According to components structure and test environment needs and based on the relationship among empty hole estimation model and ultrasonic first sound and second sound, the paper proposes length and level detection methods and has an accurate quantitative assessment to Corrugated Pipe Duck internal defects size.