交流阻抗谱法检测混凝土内部裂缝的试验研究  

Experimental Study on the Detection of Internal Cracks in Concrete by AC Impedance Spectroscopy

作　　者：彭佳[1] 

机构地区：[1]四川建筑职业技术学院材料工程系多组元合金德阳市重点实验室,四川德阳618000

出　　处：《混凝土世界》2025年第2期30-33,共4页China Concrete

基　　金：2023年四川省德阳市社会发展领域重点研发指导类项目(2023SZZ141)。

摘　　要：基于交流阻抗谱的方法,通过在混凝土内部预设裂缝,制作6组试块,研究了混凝土抗压强度与裂缝宽度之间的关系,测得了试块的Nyquist图和Bode图,并利用LCR数字电桥测试了在不同频率下试块的阻抗模值、相位角、等效串联电阻和电容值。结果表明:随着裂缝宽度的增大,试块的抗压强度明显下降,5m m裂缝试块的强度相对空白试块下降了58.3%;有裂缝试块的Nyquist图会出现起点右移的现象,Bode图显示相位角的变化幅度很小,但试块的阻抗模值随着裂缝宽度的增大而明显增大,以1000 Hz为例,5mm裂缝试块相对于空白试块的阻抗模值增加了49.6%;利用阻抗模值作为表征混凝土抗压强度的关键参数,发现二者之间存在二次多项式的关系,能通过测试阻抗模值推测出试块的抗压强度,并估计混凝土内部裂缝的宽度,从而形成了利用交流阻抗技术检测混凝土内部裂缝的新方法。This article conductes experimental research on concrete specimens containing cracks based on the method of AC impedance.Six sets of test blocks are made by presetting cracks inside the concrete,and the relationship between concrete compressive strength and crack width is compared and studied.Nyquist and Bode diagrams of the test blocks are measured,and the impedance modulus,phase angle,equivalent series resistance,and capacitance values of the test blocks are tested at different frequencies using LCR digital bridges.As a result,it show that with the increase of crack width,the compressive strength of the test block shows a significant downward trend.The strength of the 5 mm crack specimen decreases by 58.3%compared to the blank specimen.The Nyquist plot of the test block with cracks shows a rightward shift of the starting point,while the Bode plot shows a small change in phase angle,but the impedance modulus increases significantly with the increase of crack width.Taking 1000 Hz as an example,the impedance modulus of the 5 mm crack specimen increases by 49.6%compared to the blank specimen.The impedance modulus value measured by LCR is used as a key parameter to characterize the compressive strength of concrete.It is found that there is a power function relationship between the two,and the compressive strength value can be inferred through the change of impedance modulus value,thus forming a new method for detecting internal cracks in concrete using AC impedance technology.

关 键 词：交流阻抗 混凝土裂缝 阻抗参数 试验研究 

分 类 号：TU7[建筑科学—建筑技术科学]