不同搭接长度下套筒约束浆锚搭接接头力学试验研究

发布时间：2018-09-08 09:37

【摘要】：为改善已有灌浆套筒施工的便利性,提出了一种新型套筒约束浆锚搭接接头,研究了该接头的力学性能.进行了不同搭接长度下16个该搭接接头的拉伸试验,研究了接头的破坏形态、力-位移曲线、承载力、延性、钢筋应变、套筒环向应变等,并基于试验数据及平截面假定对套筒截面的内力进行分析,解释了随搭接长度变化套筒环向(拉、压)应变的变化过程.由于套筒的约束,接头的搭接长度大大减小;试验中套筒的偏转导致试件的刚度、延性小于对应钢筋的刚度、延性;搭接接头套筒中部拉力比对接接头小,对套筒材料抗拉性能要求低,搭接接头钢筋通过灌浆料传递到套筒上的剪应力比对接接头小,对套筒与灌浆料的界面粘结性能要求低.当套筒长度短时,钢筋与灌浆料间出现滑移,使得套筒中部钢筋的拉力变大,套筒与灌浆料合力为压力,反之,套筒与灌浆料合力为拉力;随着搭接长度的增加,加载过程中套筒中部近钢筋侧环向最大压应变增大;极限荷载时,随着搭接长度增加,套筒各测点环向拉应变总体呈降低的趋势.
[Abstract]:In order to improve the convenience of existing grouting sleeve construction, a new type of jacketed grouting anchor lapping joint is proposed, and the mechanical properties of the joint are studied. The tensile tests of 16 lap joints with different lapping lengths were carried out, and the failure mode, force displacement curve, bearing capacity, ductility, reinforcement strain, annular strain of sleeve, etc., were studied. Based on the experimental data and the assumption of plane section, the internal force of the sleeve section is analyzed, and the variation process of the circumferential (tensile, compressive) strain of the sleeve with the length of the lap joint is explained. Because of the constraint of the sleeve, the length of lap joint is greatly reduced; the deflection of the sleeve in the test results in the stiffness of the specimen, the ductility is less than that of the corresponding steel bar, and the tensile force in the middle of the sleeve of the lap joint is smaller than that of the butt joint. The tensile property of the sleeve material is low, the shear stress of the steel bar of the lap joint is smaller than that of the butt joint, and the interfacial bond property between the sleeve and the grouting material is lower than that of the butt joint. When the length of sleeve is short, slippage appears between steel bar and grouting material, which makes the tensile force of steel bar in the middle of sleeve become larger, and the resultant force of sleeve and grouting material is pressure, conversely, the resultant force of sleeve and grouting material is tension force; with the increase of lap length, In the process of loading, the maximum compressive strain of the central part of the sleeve near the side of the reinforcing bar increases, and under the limit load, with the increase of the length of the lap joint, the total circumferential tensile strain of each measuring point of the sleeve tends to decrease.
【作者单位】：同济大学结构工程与防灾研究所;
【基金】：国家自然科学基金资助项目(51322803)~~
【分类号】：TU758.12

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