Study On Nondestructive Testing And Rapid Evaluate Technical Of Prestressed Duct Grouting Quality

In recent years,With the widely used of prestressed concrete structures inengineering,The quality of this kind of engineering structure testing is becoming moreand more important. Have a binding post tensioned prestressed duct grouting is to makethe combination of the prestressed steel beam and concrete works well, reduce theburden on both ends of the anchor structure and its anchorage； protection of theprestressed steel beam are not rust corrosion, to ensure the safety and life of theprestressed concrete structure or component；However,due to construction workers inthe process of grouting technology is not mature,Pore blockage, swelling andconsistency indicators of grout do not control well, pressure is not enough whengrouting or plugging lax,bleeding rate and fluidity of the grouting slurry and otherperformance indicators did not meet the design requirements or other factors. Theremay exist cracks,voids,etc in the prestressed duct. These defects will result in partialtendon corrosion without protection,affect tendons life. Tendons can not bond well withconcrete firm as a whole, so that the prestressed not meet design requirements,structural bearing capacity decreased, and some even make structural damage.At present, there is no a set of mature testing technology standard can be used forquality detect of prestressed pipes grouting. In this paper, The author carry out a morein-depth theoretical and experimental studies of NDT in the quality detect of prestressedpipes grouting.Using the characteristics of stress wave propagation whit its variousparameters changes in concrete, research with the existing experience and analysismethods of Non-destructive-testing to testing and date analysis.this paper conducted thefollowing work:1、 Describes the development of non-destructive testing technology and itsapplications and features in the prestressed pipe grouting quality detection.Comprehensive its development at home and abroad, summarize the existing detectionmethods and its problems, Focus on the theoretical basis and its present situation ofstress wave nondestructive testing technology which based on elastic wavecharacteristics.2、Based on the basic theory of this method, Through a comprehensive analysis ofelastic wave properties of velocity, frequency and energy attenuation, establish thecorresponding relationships between attributes and channel defects, formed the testtheories basis on some experimental studies.3、Based on the principles of the impact-echo method for non-destructive testingtechniques, Creating a more complete elastic wave-based NDT techniques,Toqualitative and positioning analysis the quality of the reserved pore grouting. Theevaluation system comprehensive the properties of elastic wave propagation velocity,frequency and energy attenuation in the medium, weigh the response characteristics ofvarious attributes to the defect, The comprehensive evaluation of these three properties to the quality of the pore filling reduces the impact of each single attribute evaluationindex factors, to achieve a more ideal test results.4、 The results of this study apply to highway bridge prestressed pipe groutingquality testing assessment, combined with the characteristic of practical engineeringpreparation of the corresponding grouting quality assessment program. Establish amodel to diagnostic the tests conclusions and obtain good effect. Proved that the set ofnon-destructive testing methods for engineering is adaptability and reliability, provide auseful reference for the effective implementation detection of similar engineering.