院报 ›› 2016, Vol. 33 ›› Issue (3): 141-146.DOI: 10.11988/ckyyb.20140706

• 水工结构与材料 • 上一篇    下一篇

基于声发射的自然与饱水状态混凝土动态劈拉特性对比

邹三兵1,2, 杨乃鑫1,2, 罗曦1,2, 彭刚1,2   

  1. 1.三峡地区地质灾害与生态环境湖北省协同创新中心,湖北 宜昌 443002;
    2.三峡大学 土木与建筑学院,湖北 宜昌 443002
  • 收稿日期:2014-08-13 出版日期:2016-03-01 发布日期:2016-03-09
  • 通讯作者: 彭 刚(1963-),男,湖南岳阳人,教授,博士生导师,研究方向为混凝土材料动力特性及结构抗震,(电话)13972604433(电子信箱)gpeng158@126.com。
  • 作者简介:邹三兵(1990-),男,湖北汉川人,硕士研究生,从事结构工程、混凝土材料动力特性及结构抗震的研究,(电话)13277238692 (电子信箱)784268182@qq.com。
  • 基金资助:
    国家自然科学基金项目(51279092)

Comparative Analysis on Dynamic Split Characteristics of Natural and Water Saturated Concretes Based on Acoustic Emission

ZOU San-bing1,2, YANG Nai-xin1,2, LUO Xi1,2, PENG Gang1,2   

  1. 1.Collaborative Innovation Center for Geo-hazards and Eco-environment in Three Gorges Area, Yichang 443002, China;
    2.School of Civil Engineering and Architecture, China Three Gorges University, Yichang 443002, China
  • Received:2014-08-13 Online:2016-03-01 Published:2016-03-09

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摘要： 为研究自然状态与饱水状态混凝土的动态劈拉特性,进行了不同应变速率(10-5/s ,10-4/s ,10-3/s ,10-2/s)下的径向劈拉试验,对混凝土劈拉强度进行了深入分析,并利用实时采集的声发射数据分析自然状态与饱水状态混凝土在劈拉破坏全过程中的能量释放特性及破坏规律。结果表明:自然状态和饱水状态混凝土的劈拉强度随加载速率的增加而增大。在低应变速率(10-5/s,10-4/s和10-3/s)时,由于自由水的楔入作用,饱水状态混凝土的劈拉强度比自然状态混凝土的劈拉强度小;在应变速率为10-2/s时,由于Stefan 效应,饱水状态混凝土的劈拉强度比自然状态混凝土大;饱水状态混凝土的动态增强因子比自然状态混凝土的大,饱水状态混凝土率敏感性更显著;声发射信号特征与混凝土的破坏特性相一致,实时采集的声发射信号可对混凝土的劈拉破坏过程进行较准确的监测。

关键词: 混凝土, 饱水状态, 应变速率, 动态劈拉特性, 声发射

Abstract: Radial splitting tensile tests for natural and water saturated concrete specimens with size of Φ150×150mm was carried out under different strain rates(10-5,10-4,10-3 and 10-2s-1). Splitting tensile strength of concrete was analyzed in detail, and energy release characteristics and damage law of natural and water saturated concretes were researched in the whole process of splitting tensile damage by real-time acoustic emission data. The results show that: 1) with the increase of loading rate ,splitting tensile strength of natural and water saturated concretes increases; 2) at low strain rates (10-5,10-4 and 10-3/s), the splitting tensile strength of water saturated concrete is smaller than that of natural concrete due to the wedging action of free water, whereas at the strain rate of 10-2/s, the splitting tensile strength of water saturated concrete is larger than that of natural concrete due to Stefan effect; 3) dynamic enhancement factor of water saturated concrete is larger than that of natural concrete, and strain rate sensitivity of water saturated concrete is more obvious; 4) acoustic emission signal characteristics is in accordance with concrete failure characteristics, and acoustic emission data can be used to accurately monitor the process of concrete splitting tensile failure.

Key words: concrete, water saturated, strain rate, dynamic splitting tensile characteristics, acoustic emission

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