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碩士論文公告區 |
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| 年度： | 95 | |
| 姓名： | 張耀鍾(Yao-chong Chang) | |
| 論文題目(中)： | 以透地雷達法檢測混凝土構件火害後的劣化程度 | |
| 論文題目(英)： | Using Short-Pulse Ground Penetration Radar to Investigate the Concrete after High-Temperature Exposure | |
| 摘要(中)： | ||
| 火災發生後在高溫的作用下，混凝土的表面會劣化，對混凝土結構物的安全產生影響，本研究主要目的為研發新的電磁波檢測方法，檢測混凝土在火害前後之差異性，並作為估計劣化程度之準則。 本研究使用1GHz天線，經由實驗分析採用抬高天線與受測物距離30cm方式檢測混凝土，分別對小型混凝土試體及大型混凝土版進行檢測，將測得火害後振幅以積分方式求得面積再除上火害前振幅面積，算出混凝土之衰減常數(AI)；另外將天線抬高30公分來檢測混凝土及金屬板，由混凝土表面反射反應，與同高度下受測面為金屬板時全反射反應比較，即可求出混凝土的介電常數(εr)。本研究即是以衰減常數及介電常數來預期混凝土劣化程度。 研究結果顯示，在小型混凝土試體火害後與火害前相較之下衰減常數有顯著的上升，介電常數也明顯的下降；大型混凝土版在火害後因試體表面剝落，所測得之衰減常數則更高，介電常數也較低。 |
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| 摘要(英)： | ||
| The surface deterioration after fire can lead to safety problems for concrete structure. The aim of this research is to develop new techniques to evaluate the degree of deterioration using the ground penetration radar. In the study, 1 GHz antenna is used and is arranged 30 cm away from the specimens. The small concrete blocks and big concrete plate were constructed for the experiment. The area enveloped by the reflective response from the concrete surface was calculated. The attenuation Index (AI) is obtained from the ratio of areas after and before the fire damage. On the other hand, the dielectric constant of concrete is also used as the parameter for evaluating the concrete deterioration. The dielectric constant is evaluated by the ratio of amplitudes reflected from the concrete surface and the metal surface. The test results show the attenuation indexes are higher and the dielectric constants are lower for the small specimens after high-temperature exposure. The scaling on the surface leads to even higher attenuation indexes and lower dielectric constants for big concrete plate after fire exposure. |
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| 檔案： | 沒有相關檔案 | |
| 相關連結： | http://ethesys.lib.cyut.edu.tw/ETD-db/ETD-search-c/view_etd?URN=etd-0831107-135406 | |