TN437 : Evaluation of quality and integrity of concrete structures using “impulse response” non-destructive method – case study: the bridges of a part of Denmark’s railway network
Thesis > Central Library of Shahrood University > Mining, Petroleum & Geophysics Engineering > MSc > 2014
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Abstarct: Non-destructive testing (NDT) is a wide group of analysis techniques used in science and industry to evaluate the properties of a material, component or system without causing damage. Nowadays, Non-destructive tests play an important role in many industries. For example evaluating the safety of air craft, vehicles, trains, pipe lines, bridges and other structures, powerhouses, Refineries, oil platforms and many other examples is done with NDT. Indeed, we can say that NDT is a quality control instrument.
The destructive methods which are used to evaluate the quality and integrity of concrete structures are almost costly and doing them spends much time. In addition, the result of the test couldn’t be generalized for the all of structure. But by using impulse response method, which is a non-destructive method, we can reduce costs, reduce spending time and also do it for the all-over of the structure.
Non-destructive tests are so diverse and are in depended to physical properties and conditions of the under test material. This test that is an in situ test has a seismic baxse. In this test, a low-strain impact sends stress waves through the pile. The impactor is usually a 1-kg sledgehammer with a built-in load cell in the hammerhead. According to the elastic properties of the under test element, we can impact a strike with a pressure varying between 5 to 50 MPa. Response to the input stress is normally measured using a velocity transducer (geophone). After data acquisition, we should process the data and finally we should obtain counter graphs and by interpreting them, we can estimate the conditions of the under test structure.
In this thesis, we have studied the bridge arches of a part of the Denmark’s railway network as the case study. These arches are usually constructed by bricks and we have evaluated the support of brick laxyers using impulse response method. The obtained results from this test, according to the terms of the drilled cores, shows that Impulse response non-destructive test has a good performance and its results are completely reliable
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