钢筋锈蚀后与再生混凝土间粘结滑移性能试验研究

Experimental Study on Bond-slip Properties between Corroded Rebar and Recycled Concrete

为研究螺纹钢筋锈蚀后与再生混凝土间粘结滑移性能,采用室内加速通电锈蚀方法,分别以再生骨料取代率(0%、50%、100%)及目标钢筋锈蚀率(0%、0.5%、1.5%、2.5%)为主要参数,完成了两种水灰比下23组钢筋-再生混凝土试件的拉拔试验,获得了再生混凝土与不同锈蚀程度螺纹钢筋间的荷载-滑移曲线。基于试验结果,分析了再生骨料取代率、钢筋锈蚀率对钢筋-再生混凝土间起始滑移粘结强度、极限粘结强度、粘结模量、粘结滑移曲线的影响。研究结果表明:随着锈蚀率增加,钢筋与再生混凝土间的极限粘结强度、起始滑移粘结强度与极限粘结强度的比值呈下降趋势;再生混凝土胀裂后,钢筋与再生混凝土间的粘结刚度显著退化,一旦再生混凝土开裂后,粘结刚度下降幅度不明显。

Bond-slip properties between corroded rebar and recycled concrete were investigated using 23 pull out tests, which considered different levels of recycled aggregate（0% ,50%, 100% ） and corrosion rates of rebar （0%, 0.5% , 1.5% , 2.5% ） , electrochemical method was adopyed to accelerate rebar corrossion. The load-slip curves of reinforced recycled concrete were obtained through the tests, and the effect of recycled aggregate replacement and corrosion to bond-slip behavior were analyzed. The results show that with the increased of corrosion rate, bond strength and the between bond strength corresponding first slip and ultimate bond strength tended to decline, the bond stiffness between recycled concrete and corroded rebar significantly degraded, while decreased not obviously once the recycled concrete occured cracks.