性能增强再生混凝土框架中节点抗震性能试验

为提高再生混凝土框架结构中节点的抗震性能,利用微硅粉和混杂纤维对再生混凝土进行性能增强,对4根相同轴压比、配筋率和再生骨料取代率条件下,不同微硅粉和混杂纤维掺量的框架柱中节点进行低周反复荷载下的抗震性能试验,对比研究普通再生混凝土与性能增强再生混凝土的破坏形态、滞回特性、延性性能、耗能特性以及变形特点等问题.试验结果表明:性能增强再生混凝土节点破坏过程均经历了初裂、通裂、极限和破坏四个特征阶段;在破坏形态、滞回曲线、延性性能、节点变形及耗能特性方面,性能增强再生混凝土均优于普通再生混凝土,尤其在破坏形态和延性方面表现突出;微硅粉和混杂纤维含量的提高,性能增强效果有下降趋势;经微硅粉和混杂纤维性能增强再生混凝土节点抗震性能明显提高,可在有抗震设防要求地区的结构中使用.

Experimental Study on Seismic Behavior of Interior Joints in Enhancements Recycled Aggregate Concrete Frame

In order to improve seismic performance of interior joints in the recycled concrete frame structures, silica powder and hybrid fiber were used to improve the seismic performance of recycled concrete. Under the same axial compression ratio, and with the same reinforcement ratio and recycled aggregate replacement ratio, four interior-joints of the frame columns were manufactured by different amount of silicon powder and hybrid fiber. Low cyclic lateral loading tests were performed to study and compare the failure mode, hysteretic behavior, ductility, energy dissipation, and deformation characteristics between the common recycled concrete and enhanced recycled concrete. The test results show that the recycled concrete interior-joints experienced four stages including initial crack, general crack, ultimate state, and damage. Meanwhile, the performance of enhanced recycled concrete is superior to that of common recycled concrete, such as the failure pattern, hysteresis curve, ductility performance, deformation, and energy dissipation, especially in terms of failure pattern and ductility. Additionally, with the increase of silicon powder and mixed fiber content, the improvement effect has a downward trend, while due to the application of silicon powder mixed with hybrid fiber, the seismic performance of the recycled concrete interior-joints is obviously improved. Therefore, this enhanced recycled concrete can be applied to the structures in the seismic fortification regions.