循环荷载作用下珊瑚混凝土的阻尼特性

Damping Characteristics of Coral Concrete Under Cyclic Loading

以珊瑚砾石、珊瑚砂拌和海水、水泥及减水剂制备全珊瑚砂混凝土。开展不同上限应力、下限应力及不同加载频率下的正弦波循环加载、卸载试验,得到了珊瑚混凝土阻尼比随变形破坏全过程演化曲线,分析了荷载波形参数对珊瑚混凝土阻尼特性的影响及机理。结果表明:阻尼比随循环周次呈现初始衰减、稳态和加速3阶段演化特征;珊瑚混凝土平均阻尼比为3.9%~5.9%,高于普通混凝土,主要归因于珊瑚骨料多孔隙、多棱角和易破碎性质;提高上限应力、降低下限应力水平或提高加载频率均会使珊瑚混凝土阻尼比增大,且阻尼比对上限应力的变化最为敏感,对下限应力变化次之,对频率变化敏感度最低。

A whole coral sand concrete was prepared via mixing coral gravel, coral sand with seawater, cement and water reducer. The coral damping ratio with the deformation and failure process of concrete evolution curve was investigated by upper limit stress, lower limit stress at different loading frequencies and sine wave cycle and unloading tests. The load waveform parameters on the coral damping characteristics of concrete law and the mechanism were also analyzed. The results show that the damping ratio has the characteristics of initial attenuation, steady state and acceleration. The average damping ratio of coral concrete is 3.9%–5.9%, which is greater than that of ordinary concrete. Increasing the upper limit stress, decreasing the lower limit stress or increasing the loading frequency will increase the damping ratio of coral concrete, and the damping ratio is the most sensitive to the change of the upper limit stress rather than the change of the lower limit stress, and the lowest sensitive to the change of frequency.