高延性混凝土与钢筋黏结性能的试验研究  

Experimental study on bond behavior between steel bar and high ductility concrete

作　　者：邓明科[1] 潘姣姣 梁兴文[1] 

机构地区：[1]西安建筑科技大学,陕西西安710055

出　　处：《土木工程学报》2018年第3期19-26,35,共9页China Civil Engineering Journal

摘　　要：通过12组试件的中心拉拔试验,研究高延性混凝土(High Ductility Concrete,简称HDC)与钢筋的黏结性能,分析钢筋直径、钢筋外形、HDC强度、保护层厚度和纤维掺量对高延性混凝土与钢筋黏结滑移曲线特征点的影响。试验结果表明:(1)纤维桥联应力的横向约束作用限制了高延性混凝土内部径向裂缝的宽度,其耐损伤能力提高,试件发生拔出破坏或劈裂-拔出破坏;(2)与普通混凝土对比,高延性混凝土与光圆钢筋的黏结强度提高1.79倍,残余黏结强度提高1.96倍;(3)根据试件的破坏形态,确定HDC与带肋钢筋的临界相对保护层厚度为3.41;(4)随着纤维体积掺量的增加,其增韧和阻裂效果越好,黏结韧性指数I_(0.85)和I_(0.5)分别提高了35%和41%;(5)根据试验结果,提出HDC与带肋钢筋的黏结强度计算公式,建立适用的黏结应力-滑移本构模型,且模型曲线与试验曲线吻合良好。The pull-out experiments were conducted on 12 specimens to investigate the bond property between steel bar and High Ductility Concrete （HDC）. The effects of rebar diameter, rebar shape, strength of HDC, thickness of concrete cover and content of fibers on characteristic point of bond stress-slip curves were analyzed. The experimental results show that the HDC specimens shall fail in the pull-out mode or split-pullout mode, since the lateral restraints of fiber bridging stress limits the width of radial cracks in HDC, enhancing the damage resistance of HDC. Compared to the ordinary concrete, the bond strength between HDC and plain round bar can be increased 1.79 times strength can be enhanced 1.96 times. According to the failure modes of specimens, the critical the combination of HDC and ribbed bars was determined to be 3.41. With the increase of fiber and the residual bond relative cover （c/d） for amount, the toughening and fracture resistance can be improved, and the bond toughness indices （I0. 85 and I0.5 ） can be improved by 35 percent and 41 percent, respectively. Based on the experimental results, a calculation formula for calculating the bond strength between HDC and ribbed bars was proposed, and a suitable bond stress-slip constitutive model was established, based on which the predicted curves agreed well with the experimental curves.

关 键 词：高延性混凝土 黏结应力.滑移关系 黏结强度 拔出试验 韧性指数 

分 类 号：TU502[建筑科学—建筑技术科学]