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碩士論文公告區 |
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| 年度： | 96 | |
| 姓名： | 洪士凱(Shih-Kai Hung) | |
| 論文題目(中)： | 火害後鋼筋握裹力檢測評估－應力波法 | |
| 論文題目(英)： | Assessment of the bond strength of concrete structures after fire using Stress Wave Method | |
| 摘要(中)： | ||
| 本研究的目的是希望能藉由應力波法檢測混凝土於火害後的劣化深度，並利用拉拔試驗求得鋼筋握裹狀況。檢測方法是於混凝土表面以鋼珠做敲擊源敲擊，將接收器設置於20cm之距離，以所得到之頻譜中的主要反應頻率來評估混凝土的劣化程度。 本研究之試體分為二種，一為240×100×18cm3大型混凝土板，火害溫度500、600、800℃；另一為40×40×20cm3及40×40×30cm3之小型混凝土試體，受到火害溫度為600與800℃。先以大型混凝土試體利用應力波法作表面頻率量測後在鑽心，經由鑽心試體切片之動態彈性模數來判定劣化深度，以所得之表面頻率與劣化深度作分析，求得與前期研究小型混凝土試體的結果一致性，發現尖峰頻率越低則劣化深度越深且呈線性降低，故發展出計算表面量測頻率之劣化深度的公式，並探討拉拔試驗與其劣化深度的關聯性，再針對小型混凝土試體的表面頻率與試體厚度的相關性。 由此可知當計算劣化深度大於鋼筋保護層，鋼筋握裹力亦較低。從拉拔試驗得知計算劣化深度大於鋼筋保護層，其鋼筋握裹力亦較低。小型混凝土試體的結果發現在承受相同高溫下之最低尖峰頻率值，不受試體厚度影響而改變。 |
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| 摘要(英)： | ||
| The aim of the present research is to evaluate the degree of deterioration of concrete after fire by means of stress waves, bond strength using pullout test. In the study, a steel ball is used as the impactor and the frequency of the principal response obtained by a receiver 20 cm away is used for concrete evaluation. Two types of specimens were investigated. One is the large concrete plate with the size 240×100×18 cm3. These specimens were heated by oven with the temperatures 500, 600, and 800℃. The others are the small specimens with the size 40×40×20 cm3 and 40×40×30 cm3. These specimens were heated by oven with the temperatures 600 and 800℃. The frequencies of the principle responses of the large specimens were compared to the depth of concrete deterioration obtained from drilled core. The cores were sliced into disks and the depth of the deterioration was evaluated by the dynamic elastic modulus of the disks. It was found the lowest primary frequency is linearly decreased with the depth of deterioration. A formula between the depth of deterioration and the lowest primary frequency is developed based on the experimental results obtained from these big concrete plates and small specimens constructed in previous study. It was also found that the pull-out strength of the steel reinforcement is lower when the calculated depth of deterioration is larger than the cover thickness. The results of the small specimens show the lowest primary frequency is similar for specimens withstanding the same high temperature but with different thickness. |
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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-0826108-125026 | |