施工縫力學(xué)特性及對RC柱抗震性能影響分析*
李英民1,2，于婧1，夏洪流1,2，鄭妮娜1
- 摘 要
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李英民1,2，于婧1，夏洪流1,2，鄭妮娜1（1 重慶大學(xué)土木工程學(xué)院， 重慶 400045；2 山地城鎮(zhèn)建設(shè)與新技術(shù)教育部重點實驗室（重慶大學(xué)）， 重慶 400045）［摘要］對帶縫試件和整澆試件進行了靜力試驗和擬靜力試驗研究施工縫的力學(xué)性能。結(jié)果表明施工縫對混凝土的受壓性能幾乎沒有影響，對混凝土的受拉和受剪性能影響較大；施工縫處混凝土的抗拉強度只有母體抗拉強度的一半，拉力主要由穿過接縫面的鋼筋承擔；純剪切狀態(tài)下，施工縫處混凝土的抗剪強度約為母體混凝土的40%；帶縫構(gòu)件的抗剪承載力主要取決于軸向荷載作用和穿過縫面的縱向鋼筋的銷栓作用。鋼筋混凝土結(jié)構(gòu)中的施工縫可能會造成應(yīng)力集中，把破壞區(qū)域限制在很小的范圍內(nèi)，對構(gòu)件的抗震性能形成不利因素；但同時也有可能通過縫面摩擦力消耗地震能量，此時反而會對抗震性能有益。具體哪種情況占主導(dǎo)地位，取決于接縫面法向和切向應(yīng)力的相對大小。［關(guān)鍵詞］施工縫；力學(xué)特性；靜力試驗；擬靜力試驗；抗震性能中圖分類號：TU375 文獻標識碼：A 文章編號：1002-848X(2013)05-0065-06Mechanical properties of construction joint and influence on seismic behavior of RC columnLi Yingmin1,2, Yu Jing1, Xia Hongliu1,2, Zheng Nina1(1 The College of Civil Engineering of Chongqing University, Chongqing 400045, China; 2 Key Laboratory of New Technology for Construction of Cities in Mountain Area (Chongqing University),Ministry of Education, Chongqing 400045, China)Abstract: Static tests and pseudo-static tests were conducted to investigate the mechanical properties of construction joint of jointed specimens and integral casting specimens. Tests results show that construction joint has little effect on the compressive force characteristics and has great influence on tensile and shear properties of concrete. The tensile strength of jointed concrete is about half of the parent concrete and it could be neglected in the numerical analysis. And the tensile force of joint is born mainly by lengthways reinforcements passing through the joint. In pure shear condition, the shearing capacity is about 40 percents of that with integral concrete in the construction joint. The shear capacity of jointed specimens depends on the compressive forces and the dowelling action of the main reinforcement passing through the joint. Construction joints of reinforced concrete structures may cause stress concentration, which will strict the damage area in a small range and adverse factors will be formed for seismic performance. Which kind of specific situation is dominant depends on the relative size of normal stress and shear stress of joint surface.Keywords: construction joint; mechanical property; static test; pseudo-static test; seismic behavior*重慶市科技攻關(guān)項目（CSTC，2010AB0007）。作者簡介：李英民，教授，博士生導(dǎo)師，Email: liyingmin@cqu.edu.cn。參考文獻［1］李英民，劉立平.汶川地震建筑震害與思考［M］. 重慶：重慶大學(xué)出版社,2008.［2］WATERS T. A study of the tensile strength of concrete across construction joints ［J］. Magazine of Concrete Research, 1954, 6(18):151-153.［3］GB 50011—2010建筑抗震設(shè)計規(guī)范［S］. 北京：中國建筑工業(yè)出版社，2010.［4］宋玉普，魏春明. 混凝土施工縫接縫面劈拉強度試驗研究［J］.混凝土, 2006(6):22-25.［5］MONKS W L. Treatment of construction joints ［J］. Concrete, 1974, 8(2):28-30.［6］ISAO U, YOSHIDA N, MORISHITA S. Evaluation of mechanical properties of construction joint between new and old concrete under combined tensile and shear stresses ［J］.Journal of the Society of Materials Science, 1998, 47 (1): 73-88.［7］LOPEZ-BATIZ O. Behavior of reinforced concrete frame structures with construction joints under lateral loads ［J］. Magazine of Concrete Research, 1998, 50 (2):133-145.［8］于婧, 李英民, 夏洪流. 施工縫對框架柱抗震性能影響的試驗研究［J］. 土木工程學(xué)報, 2011, 44（S1）: 81-86.［9］李英民，于婧，夏洪流. 施工縫模型及在鋼筋混凝土柱非線性分析中的應(yīng)用［J］. 土木建筑與環(huán)境工程, 2011, 33(5): 1-6.
