高强自密实再生块体混凝土单轴受压声发射特性

Acoustic Emission Characteristics of High-Strength Self-Compacting Recycled Lump Concrete Under Uniaxial Compression

为研究高强自密实再生块体混凝土单轴受压声发射特性,对取代率分别为0%,10%,20%的立方体混凝土试块进行轴心受压试验.将受压破坏过程分为4个阶段,引入活跃系数对能量进行分析,并通过b值-能量分析判断裂纹的开展程度和试块的损伤情况.结果表明:随着取代率的提高,峰值应力前声发射活动强度显著增加,能量越早出现爆炸性增长;活跃系数随应力进程先升高后降低,活跃系数可作为混凝土是否适合继续服役的判断标准;通过b值-能量分析能够准确地判断裂纹的开展程度和试块的损伤情况.

In order to study the acoustic emission characteristics of high-strength self-compacting recycled lump concrete under uniaxial compression,the axial compression tests were carried out on the cube concrete specimens with replacement rates of 0%,10%and 20%respectively.The compression failure process was divided into four stages,the active coefficient was introduced to analyze the energy,and according to the b value energy analysis,the crack development degree and the damage condition of the specimens were judged.The results show that:with increasing the replacement rates,the intensity of acoustic emission activity before peak stress increases significantly,and the energy increases explosively earlier.The active coefficient initially increases and then decreases with the stress process,which could be used as a criterion to judge whether the concrete is suitable for continuous service.According to the b value energy analysis,the crack development degree and the damage condition of the specimens could be accurately judge.