短锚固条件下钢筋混凝土动态粘结性能试验研究

Experimental Study on Dynamic Bonding Performance of Reinforced Concrete with Short Anchor

为探究钢筋混凝土的动态粘结性能,综合分析加载速率和混凝土强度对短锚固试件破坏形态、粘结强度及加载端滑移量的影响,开展18个约束良好试件在不同加载速率下的轴心拔出试验,描绘出钢筋加载端的荷载-滑移量关系曲线,并根据沿钢筋埋置长度分布的应变计算得出主筋弹性阶段的粘结应力。研究结果显示:良好约束试件破坏形态与加载速率无关,混凝土强度的提高会使构件趋于断裂破坏;高加载速率和高混凝土强度有助于增大试件的粘结强度,使粘结应力的分布集中在加载端。结论表明,在高加载速率或高混凝土强度条件下,传统短锚固钢筋粘结应力的均匀分布假设并不适用。

In order to explore the dynamic bonding performance of reinforced concrete, and comprehensively analyze the effects of loading rate and concrete strength on the failure morphology, bond strength, and load-side slip of short-anchored specimens, axial pullout tests were conducted on 18 well-constrained specimens at different loading rates, the load-slip relationship curve at the loading end of the steel bar was drawn, and the bonding stress at the elastic stage of the main bar was calculated based on the strain distribution along the embedded length of the steel bar. The study results showed that the failure shape of the well-constrained specimens has nothing to do with the loading rate, and the increase in the concrete strength make the components tend to fracture and failure;The high loading rate and high concrete strength help to increase the bonding strength of the specimens, so that the distribution of bond stress is concentrated at the loading end. The conclusions showed that under the condition of high loading rate or high concrete strength, the traditional assumption of uniform distribution of bonding stress of short anchored steel bars is not applicable.