铅锌尾矿砂对混凝土单轴压缩声发射特征的影响研究

Influence of Lead-Zinc Tailing Sand on Acoustic Emission Characteristics of Concrete under Uniaxial Compression Tests

为了研究尾矿砂骨料混凝土的力学特性,对4种铅锌尾砂含量的混凝土开展单轴压缩实验,同时获取了压缩过程中的声发射信号,基于声发射信号对材料损伤演化特征进行了评价。结果表明:混凝土试件的变形过程分为弹性、塑性、断裂破坏和残余变形4个主要阶段;随着铅锌尾砂取代率增加,抗压强度有增大趋势,并在超过30%后趋于稳定;根据声发射实验得到了损伤因子与应变的关系曲线;普通混凝土结构损伤主要在塑性变形阶段,尾矿砂改性混凝土的结构性损伤集中在塑性和断裂破坏阶段;一定比例的铅锌尾砂有助于加速水化凝胶物的形成,从而增强强度和变形性能。

In order to study the mechanical properties of tailings aggregate concrete,uniaxial compression tests were carried out on concrete with four kinds of lead-zinc tailing sand,and the acoustic emission signals during compression were obtained,and the damage evolution characteristics of the material were evaluated based on the acoustic emission signals.The results show that the deformation process of concrete specimens can be divided into four main stages:elastic,plastic,fracture and residual deformation.With the increase of replacement ratio of lead-zinc tailing sand,the compressive strength increases and becomes stable after more than 30%.The relation curve between damage factor and strain was obtained by acoustic emission test.The structural damage of ordinary concrete is mainly in the plastic deformation stage while the structural damage of tailing sand modified concrete is mainly in the plastic and fracture failure stage.A certain proportion of lead-zinc tailing sand helps to accelerate the formation of hydrated gels,thus enhancing the strength and deformation properties.