| Summary: | 碩士 === 朝陽科技大學 === 營建工程系碩士班 === 93 === This dissertation is a study to evaluate internal defects condition in repair of concrete using the impact-echo transfer function. Explore the transfer response of differ depth delaminations in the plate-like structures .In plate-like structures sush as bridge decks, slabs and infill walls in frames, cracking often occurs in the form of delaminations in the plane of the reinforcing bars. Thus in repair and rehabilitation of concrete structures is to determine the extent of cracking at first and after finishing the repair work, to determine the amplitude of delaminations full filled epoxy and evaluate internal defects condition of concrete.
The different diameters of cracks may lead to different spectral amplitude corresponding to concrete layer. The experimental show results by the images of the different positions of the impact relative to the plane of the delamination. Thus it is possible to non-destructively evaluate the nuclear power station, reservoir dike or, prestressing force beam which is unfit for coring. The purpose of this study is as following.
1. Using numerical simulation to study the relationship between ratio of different horizontal crack’s length and depth and the spectral amplitude in transfer function.
2. Explore the amplitude of the different length delaminations in the plate-like structures.
Using numerical simulation to obtain the relationship between ratio of horizontal delaminations’ W/H and the spectral amplitude in transfer function.Can project the size of horizontal delaminations is more large and it’s amplitude is more to approach the plate’s amplitude. The spectral amplitude of experimental results and numerical results show, the spectral amplitudes values of delaminations full filled epoxy is about half of the the spectral amplitudes values of delaminations unfull filled epoxy. The correlation is high. In waveform analysing,evaluate the 10cm depth of delaminations part filled epoxy 1cm.The spectral frequecy show, the condition of the 10cm depth of delaminations and the 10cm depth of delaminations part filled epoxy 1cm are similar. Experimental results show, the images of the different positions of the impact relative to the specimen, approach to the numerical simulation amplitudes. Take the experimental parameters into the previously developed equation for relating peak-amplitude to the thickness of a pure concrete plate without substrate layer. The predicted amplitude for the 5 cm-thick plate is 2.3779, which has 0.34% error to the average experimental amplitude, 2.3697
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