| The comprehensive ultrasonic method is the important part of the bridge nondestrutive test. This method is applied in each aspect of the bridge structure test. Along with the improvement on the demand of the accuracy and the requirement of practical engineering, the NDT method gradually develops from traditional methods to the comprehensive methods, which are the combination of the static load, dynamic load and NDT. The purpose of test has already gradually developed from the structure defect test to the structure evaluation on the structure performance. The request of the NDT has developed from the qualitative test to quantitative evaluation with high accuracy. Therefore, the problem is to be resolved urgently with the various factors taken into consideration in test theories and actual test examination methods. Consequently, the test result can be corrected reasonably and the accuracy can be improved. In the light of the consideration mention above, the comprehensive ultrasonic test and analysis of one piece I-gider with varying section and test concrete specimen using comprehensive ultrasonic method and cube crushing strength test are carried out in road and bridge collaboration of the Transportation College of JiLin University. The paper consists of five chapters, among them, chapters three and four are kernels.Chapter one mainly talks about the study background, significance and contend. At present, the establishment the examination and evaluation systems for he old bridges that in use and new bridges not only become urgent need for bridge manage department, but also become the hotspot of bridge domain. Test for concrete quantity of bridge structure and the whole intensity is a very important process for bridge NDT. The concrete crack is common disease. The comprehensive ultrasonic method can be made use of to check and measure concrete crack and carry out nondestrutive evaluation.Chapter two summarizes the principle of test technique and methods when using comprehensive ultrasonic method. This chapter also generalizes the development situation of concrete defect when using comprehensive ultrasonic technique, basic principle and methods and applicable scope. Also, the function characteristics and operation methods of ultrasonic test instrument and ultrasonic converter used in this test. In addition, combining the actual experience, the influencing factors such as transverse size, temperature, humidity, and moisture, steel position in concrete and ratio, coupling state of converter etc. and corresponding regulation are given.Chapter three studies concrete strength using comprehensive method. Firstly, the principle and methods of rebound- carbonization modified method and ultrasonic method comprehensive ultrasonic method using to test concrete strength is introduced. The curve specially used in the measurement of the rebound strength is established using the nonlinear bidirectional regressive match method by test concrete specimen using comprehensive ultrasonic method and cube crushing strength test. The correlation and accuracy of match curve are verified by test and error analysis.Chapter four carries out the nondestructive test study and application on the test position of concrete reinforces and crack of beam. Firstly, analyzing and summarizing the cause of crack and crack type, the crack depth evaluation methods using at present and combining the application of comprehensive ultrasonic in the nondestructive test. Considering interior reinforcing steel bar of concrete inflection for crack test, the theory study and research carrying out for interior steel test. The ZBL-R620 reinforcing bar test instrument is used to test the position of concrete reinforces and protective coating and reinforces diameter; in this foundation, the crack depth is tested with the comprehensive ultrasonic method, the distributing picture can be acquired.Chapter five is summary of the paper in which the content and direction are pointed out for further study. |
PDF Full Text Request