不同骨料来源再生混凝土常规三轴受压性能研究

Experimental study on mechanical properties of recycled concrete in tri-axial compression

为了研究三轴应力状态下不同骨料来源再生混凝土的力学性能,以再生粗骨料来源、侧向围压值为变化参数,设计12个圆柱体试件进行常规三轴试验研究。通过试验观察了试件的破坏形态,获取了试件应力-应变全过程曲线及峰值应力、峰值应变、弹性模量等特征参数,并深入分析了三轴受压下再生混凝土耗能能力、做功、延性性能。研究结果表明:单轴受压时,再生混凝土为纵向劈裂破坏,三轴受压下,为斜向剪切破坏;增大侧向围压值,可有效提高再生混凝土的初始刚度、峰值应力和峰值应变;再生粗骨料的来源对再生混凝土的耗能能力、延性性能有一定的影响,耗能能力、延性性能随着围压值的增大而提高。研究结果为再生混凝土的进一步科学研究和推广应用提供参考。

In order to study the mechanical behaviors of recycled coarse： aggregate concrete under tri - axial compression, 12 cylinder specimens were designed for conventional tri - axial test, and two parameters are taken into consideration as the major parameters in the test,which is the recycled coarse aggregate sources and lateral confinement. The failure patterns of the specimens were observed, the stress- strain curve, peak stress, peak strain , elastic modulus were obtained. The energy dissipation capacity, work, and ductility per- formance of recycled coarse aggregate concrete were analyzed.The study indicates that the failure pattern of recycled concrete is vertical fracturing subject to the uniaxial compression, whereas under triaxial compression the failure pattern is oblique shear failure;Increase the lateral confinement can effectively improve the initial stiffness ,the peak stress and peak strain of recycled concrete;The source of the re- cycled coarse aggregate has a certain influence to energy dissipation and ductility performance of recycled concrete;With the increase of lateral confinement,the energy dissipation and ductility performance improve significantly.The research would be helpful for further re- search and provide reference for application on recycled concrete.