摘要
无损检测方法不破坏混凝土结构性能,采用其评价混凝土抗压强度一直是本领域的研究重点之一。为掌握不同应力波特征参数与混凝土抗压强度之间的相关性,设计成型4种强度等级的混凝土试件和构件来进行超声波、冲击共振波和冲击回波3种无损检测技术的试验,探讨此3种应力波波速与混凝土抗压强度之间的对应关系。研究结果表明:各应力波波速均随龄期的增加而增大,相同龄期的条件下,设计强度等级高的混凝土具有较大的应力波波速;相同抗压强度条件下,冲击共振波波速和冲击回波波速基本一致并低于超声波波速,约为超声波波速的0.9倍;所测混凝土抗压强度与3种应力波波速之间均存在显著的线性相关性,各自的相关系数均在0.92以上;超声波波速与混凝土抗压强度之间的线性相关系数在稳定程度上弱于冲击共振波和冲击回波,易受设计强度等级的影响,在较低设计强度等级下偏向于非线性关系。冲击回波波速可良好地表征20~60 MPa混凝土的抗压强度,且不易受设计强度等级的影响,结合其不需耦合剂、可单面检测和几乎不受钢筋影响的特点,冲击回波法将为钢筋混凝土结构质量的高效、可靠检测评价提供强有力的支持。
A concrete stucture’s performance is not harmed by nondestructive testing.Using it to evaluate the compressive strength of concrete has always been one of the research emphases in this field.Concrete specimens and components with four strength grades were designed to conduct tests using three nondestructive testing technologies:ultrasonic,shock resonance wave,and impact echo.The corresponding relationship between these three stress wave velocities and concrete compressive strength was discussed in order to understand the correlation between various stress wave characteristic parameters and concrete compressive strength.The results show that each stress wave velocity increases with the increase of age.Under the condition of the same age,the concrete with high design strength grade has larger stress wave velocity.Under the same compressive strength,the shock resonance wave velocity and impact echo velocity are basically the same and lower than the ultrasonic wave velocity,which is about 0.9 times of the ultrasonic wave velocity.There is a significant linear correlation between the measured concrete compressive strength and the three stress wave velocities,and their correlation coefficients are more than 0.92.The linear correlation coefficient between ultrasonic wave velocity and concrete compressive strength is weaker than impact resonance wave and impact echo in stability,which is easy to be affected by the design strength grade and tends to be nonlinear at lower design strength grade.The impact echo wave velocity can well characterize the compressive strength of 20~60 MPa concrete and is not easily affected by the design strength grade.Combined with its characteristics of no coupling agent,single-sided detection and almost unaffected by reinforcement,the impact echo method will provide strong support for the efficient and reliable detection and evaluation of reinforced concrete structure quality.
作者
尚新想
谢友均
马昆林
龙广成
SHANG Xinxiang;XIE Youjun;MA Kunlin;LONG Guangcheng(School of Civil Engineering,Central South University,Changsha 410075,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2022年第8期2305-2312,共8页
Journal of Railway Science and Engineering
基金
湖南省重点研发计划项目(2020wk2005)。
关键词
抗压强度
超声波
冲击共振波
冲击回波
线性关系
compressive strength
ultrasonic
shock resonance wave
impact echo
linear relationship
作者简介
通信作者:龙广成(1973−),男,江西万载人,教授,博士,从事先进水泥基材料及混凝土耐久性研究,E−mail:565410408@qq.com。
