型钢与钢纤维混凝土界面黏结性能及损伤耗能试验研究

为解决型钢混凝土结构中型钢与钢筋相互干扰、混凝土浇筑困难等施工难题，将构件中钢筋笼替换成钢纤维，形成型钢-钢纤维混凝土组合结构。型钢与钢纤维混凝土间的黏结性能是保证两种材料共同工作的基础，通过8个圆形截面试件与8个方形截面试件的标准推出试验，研究在不设置钢筋笼的情况下型钢与钢纤维混凝土之间的黏结性能，获得了荷载-滑移曲线、黏结强度、界面耗能等重要性能指标。结果表明：加载端与自由端的荷载-滑移曲线存在较为明显的差异，并且当荷载达到峰值承载力时，曲线的差异性表现的最为明显。圆形试件总体表现出较方形试件更好的界面黏结效果，其名义黏结强度最大可达到1.913MPa，残余黏结强度最大为0.707MPa，而方形试件相应的指标最大值分别为1.496MPa和0.609MPa。混凝土保护层厚度与黏结长度越大，受力过程中界面能够储存的黏弹性变形能越大。

Experimental study on interfacial bonding property and energy dissipation capacity between shape steel and steel fiber reinforced concrete

An innovative method is proposed to replace the steel reinforcement cage by steel fiber to form a shape steel and steel fiber reinforced concrete to solve the construction problems of steel reinforced concrete structure, such as position conflict between shape steel and steel bars, or difficulty of concrete placement. The bond behavior between the shape steel and steel fiber reinforced concrete is the foundation to ensure the cooperation of two materials. 8 circular specimens and 8 square specimens were designed and experimented by push-out testing to investigate the bonding properties between shape steel and steel fiber reinforced concrete without steel reinforcement cage. Some important performance indexes, including load-slip curve, bond strength and interfacial energy were obtained. The load-slip curves of the loading end and the free end show obvious differences, which are most obvious when the load reaches the peak load-bearing capacity. In addition, circular specimens show better interfacial bonding effect than the square specimens. The maximum nominal bonding strength of the circular specimen reaches 1.913MPa and the maximum residual bond strength is 0.707MPa, while the corresponding values for the square specimen are 1.496MPa and 0.609MPa respectively. The larger the thickness of concrete protective layer and bond length, the more viscoelastic deformation energy can be stored at the interface during the stress process.