大號鋼筋混凝土握裹裂縫以Epoxy修補後之耐震性能評估

Investigation of Cyclic Loading Resistance for Bonding Crack of Concrete and Large size Rebar Repaired by Epoxy

詹宗穎(Zong-Ying Zhan)

指導教授 ： 干裕成

朝陽科技大學/理工學院/營建工程系/碩士(2014年)

摘要

本研究主要探討大號鋼筋(D43或D57)及一般號數鋼筋(D19或D32)與混凝土間握裹裂縫經修復後之受力行為；尤其在承受到低週波返覆荷載後所造成耐震表現。並在試體修復前後之開裂行為與分析AE訊號對應，建立力學行為與AE訊號關係。
由試驗發現，在相同混凝土強度中，鋼筋直徑越大，極限應力愈小，且鋼筋與混凝土的握裹強度也跟著鋼筋直徑增加而降低之趨勢。在本研究中，靜態拉拔試驗中，試體在修復前及經修復後之握裹強度皆隨鋼筋號數增大而遞減的趨勢；唯修復後之握裹強度皆明顯提升；而其握裹強度比，則隨鋼筋號數越大而越高的趨勢。另外，在動態拉拔試驗顯示，經修復後之耐震次數皆較修復前大幅提升。除此，其靜態拉拔及動態拉拔之臨界應變能與極限滑移量皆隨鋼筋直徑越大臨界應變能越小之趨勢；不管鋼筋號數，靜態臨界應變能比至少大於2.06，平均為2.65；動態臨界應變能比至少大於2.28，平均為3.62。由上顯示，鋼筋與混凝土的握裹裂縫經環氧樹脂修補過後，可明顯提供靜態拉拔及耐震補強效果。

關鍵字

握裹裂縫

並列摘要

This research attempts to investigate the bond behavior between the concrete and steel re-bars before cracking and after being repaired by epoxy, as being subjected to cyclic load. From the test results, it showed that the ultimate pullout force increases, but the ultimate bond strength decreases as bar diameter increases. From static pull-out test, the bond strength of concrete before cracking and after being repaired decrease with the increase of rebar diameter. While, the bond strength of concrete apparently improved after reparation. Furthermore, it turned out that the restoration ratio of bond strength increases with the increase of bar diameter.
From the results of dynamic pullout test, the bond conducts higher cyclic loading resistance after reparation in terms of cyclic number at failure. For both of static and dynamic pullout tests, the critical strain energy and ultimate slip appear decreasing with the increase of rebar diameter. The critical strain energy ratios in static and dynamic pull-out tests turned out at least 2.06 and 2.28, with averages of 2.65, and 3.62, irrespectively. Eventually, the bonding cracked concrete after being repaired by epoxy performs better seismic resistance.

並列關鍵字

Bonding Crack

參考文獻

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