| Concrete-filled steel tube refers to fill the steel tube with concrete to form the composite structure. Based on the fore interaction between steel tube and the concrete,it makes full use of the strengths of two materials to make up for each other's weaknesses. It has a stronger ability of building up and the three merits of high strength,frame,template with the combination of concrete pumping technology can solve the installation of the large-span arch bridge. So it is extensivly used in engineering filed. When pouring concrete-filled steel tube, as a result of a low pumping pressure and pouring during the interruption or concrete additives and other inappropriate reasons, defects in concrete-filled steel tube may occur. Sometimes there are flaws in the concrete, thus influencing the integrity and mechanical performance of components is in different degree. So it is important to supervise and detect the concrete-filled steel tubular arch bridge construction quality.In this papar, set in Zhengzhou-Xi'an Passenger Dedicated Railway Line, cross country G310 basket concrete-filled steel tubular arch bridge, the quality of concrete pouring arch is detected by the use of ultrasonic testing. Based on test results, parts of the arch rib defects are repaired rapidly, using the new polymer materials.The main contents are summarized as follows:1. This paper systematically describes ultrasonic pulse testing theoretical foundation, discusses the acoustic wave's spread method in concrete, the characteristics of the wave field in the concrete and the relation between acoustics parameter and concrete quality.2. In this paper, produce the compacting concrete-filled steel tube, void ,debonding, empty, isolation, embedded steel plate and a dumbbell-shaped specimen, do the ultrasonic testing about the defects specimens of concrete-filled steel tube through the NM-4A with non-metallic ultrasonic testing of concrete-filled steel tube analyzer specimen and record the various acoustic parameters of ultrasound. Test results show that with the increase of the concrete ages, ultrasound in the sample velocity is in the upward trend and with the increase of ultrasonic thickness, defects of the wave velocity decreases.3. In this paper, circular steel pipe is done for the quantitative study by detecting the sonic time and we do a quantitative calculation made by calculating the chord length defects of the central angle. The feasibility of this approach can be confirmed through numerous tests.4. Different changes in ultrasound parameters are summed up in ultrasonic flaw detection through the test specimen. These research results are used to test the concrete-filled steel tubular arch bridge of cross Zhengzhou-Xi'an Passenger Dedicated Line G310 basket.5. Based on the analysis of test results, this new type of polymer materials can be used to repair the defective parts rapidly.The paper comprehensively presents the theory and method of concrete -filled tube quality, using ultrasonic detection, and combined with engineering practice of the concrete-filled steel tubular arch bridge of cross Zhengzhou-Xi'an Passenger Dedicated Line G310 basket, mainly studies parameter character and wave form character of ultrasonic wave that through concrete filled tub specimen with regular defects. Based on test results, defective parts are done the quantitative analysis by the use of sound value, which must provide a theoretical basis, The use of this new type of polymer materials for rapid repair defective parts, which have great practical value in the actual repair and reinforcement. |
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