箍筋銹蝕對鋼筋混凝土梁承載機理影響的試驗研究*
董衛(wèi)1，蘇志敏1，楊華舒1，武亮1，大下英吉2，葉嘉兵1
- 摘 要
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（1 昆明理工大學(xué)，昆明 650500； 2 中央大學(xué)，東京 1128551）
［摘要］以位移控制加載，進行了銹蝕鋼筋混凝土梁的四點受彎加載試驗。增大部分試件箍筋的間距，以研究嚴重銹蝕后箍筋剩余量較少情況下銹蝕鋼筋混凝土梁的承載機理和破壞模式。通過縱筋的應(yīng)變分布，計算各加載水平下縱筋與混凝土之間的粘結(jié)應(yīng)力。試驗表明，隨著縱筋和箍筋的銹蝕，剪跨區(qū)域的平均粘結(jié)應(yīng)力達到最大值后逐漸減?。诲^固區(qū)域的平均粘結(jié)應(yīng)力逐漸增大。銹蝕鋼筋混凝土梁的承載機理為梁效應(yīng)向拱效應(yīng)轉(zhuǎn)化過程中的復(fù)合梁拱效應(yīng)狀態(tài)，其轉(zhuǎn)化程度取決于縱筋的銹蝕率和箍筋的剩余量。根據(jù)梁拱效應(yīng)轉(zhuǎn)化的程度，提出銹蝕鋼筋混凝土梁承載機理的判斷流程圖。［關(guān)鍵詞］箍筋; 銹蝕; 極限承載力; 承載機理; 拱效應(yīng); 梁效應(yīng); 復(fù)合梁拱效應(yīng)中圖分類號：TU375.1 文獻標識碼：A 文章編號：1002-848X(2016)06-0086-05
Experimental study on stirrup corrosion effect on the bearing mechanism of reinforced concrete beamsDong Wei1, Su Zhimin1, Yang Huashu1, Wu Liang1, Oshita Hideki2, Ye Jiabing1(1 Kunming University of Science and Technology, Kunming 650500, China; 2 Chuo University, Tokyo 112 8551, Japan)Abstract:Four-point static bending tests of the corroded reinforced concrete beams were carried out under displacement controlled loading. To investigate the bearing mechanism and the failure mode of the corroded reinforced concrete beams with plenty of seriously corroded stirrups, the stirrup spacing of some specimens was increased. The bond stress distribution between longitudinal rebar and concrete under various loading levels was calculated through strain distribution of longitudinal rebar. Experiments show that, with the increase of the corrosion of longitudinal rebar and stirrups, the average bond stress of the shear span region increases to a peak value and then decreases. The average bond stress of the anchorage region increases significantly. The bearing mechanism of the reinforced concrete corroded beams is the composite beam-arch effect state that is in the process of shifting from beam effect to arch effect, and the shifting extent depends on the corrosion ratio of longitudinal rebar and the remain mass of stirrups. Based on the shifting content of beam-arch effect, the judgment flowchart for bearing mechanism of corroded reinforced concrete beams was proposed.Keywords:stirrup; corrosion; ultimate bearing capacity; bearing mechanism; arch effect; beam effect; composite beam-arch effect
*國家自然科學(xué)基金資助項目（51569011，41462013，51269007），云南省級人才培養(yǎng)項目（KKSY201204157），國家級大學(xué)生創(chuàng)新訓(xùn)練計劃（201410674002），云南省教育廳科學(xué)研究基金項目（2015Y072）。作者簡介：董衛(wèi)，博士，講師，Email：touicn@163.com。
