摘要
为研究一种煤矸石充填混凝土在高温养护条件下早龄期的力学性能,对该煤矸石混凝土在高温50℃下分别养护1 d、3 d、7 d进行单轴压缩试验。采集单轴压缩全过程中的力学参数和声发射参数;并与常温20℃养护的情况进行对比。研究了该煤矸石混凝土在不同加载阶段的声发射特性。研究表明:高温(50℃)养护条件有利于煤矸石混凝土早期强度的提高,而且这种煤矸石混凝土的早期强度满足设计要求。在单轴压缩过程中,煤矸石混凝土声发射振铃计数的峰值出现在应力峰值的附近;这一现象可以作为煤矸石混凝土破坏失稳的预兆。声发射累计振铃计数和累计能量计数随时间变化趋势一致,声发射累计参量从缓慢增长到快速增长的现象可作为预测煤矸石混凝土加速损伤,临近失稳破坏的前兆信息。与常温养护条件相比,高温养护条件下的煤矸石混凝土声发射活动更强,利用声发射可以更有效地监测高温情况下煤矸石混凝土的破坏。
In order to study the mechanical properties of a coal-gangue-filled concrete at early age under high temperature curing condition and uniaxial compression,the coal-gangue concrete was subjected to test at 1 d,3 d and 7 d under 50℃curing conditions.Compared with the case of curing at room temperature of 20℃,the mechanical parameters and acoustic emission parameters were collected in the whole process of uniaxial compression to study the acoustic emission characteristics of the coal-gangue concrete at different loading stages.The research showed that,high temperature(50℃)curing conditions are conducive to the early strength of the coal-gangue concrete,and the early strength meets the design requirements.In the uniaxial compression process,the peak value of the acoustic emission ringing count of coal-gangue concrete appears near the peak of stress,and the phenomenon can be used as a precursor of the coal-gangue s damage.The acoustic emission cumulative ringing count and cumulative energy count have the same trend with time,and the phenomenon of acoustic emission cumulative parameters from slow growth to rapid growth can be used as predictors of the accelerated damage and closing to destabilization failure of the coal-gangue concrete.Compared with the curing conditions at room temperature,the acoustic emission activity of coal-gangue concrete is stronger under high temperature curing condition,and the destruction process of coal-gangue concrete can be monitored more effectively by acoustic emission under the high temperature.
作者
宿辉
李琦
屈春来
杨家琦
康率举
刘翌晨
SU Hui;LI Qi;QU Chun-lai;YANG Jia-qi;KANG Shuai-ju;LIU Yi-chen(College of Water Conservancy and Hydropower,Hebei University of Engineering,Handan 056001,China)
出处
《科学技术与工程》
北大核心
2018年第8期120-124,共5页
Science Technology and Engineering
基金
河北省教育厅科研项目(QN2015157)资助
关键词
煤矸石混凝土
声发射
高温养护
早龄期
单轴压缩
coal-gangue concrete
acoustic emission
high temperature curing
early age
uniaxial compression
