基于瞬态冲击响应的混凝土路面板脱空识别

Void Identification of Concrete Pavement Slab Based on Transient Impulse Response

为开发混凝土路面板脱空检测专用仪器,降低检测费用和简化检测方法,在现有脱空检测方法的基础上,根据脱空板振动频率及在定量冲击激励下振幅的变化规律,提出了混凝土路面板脱空识别的瞬态冲击响应法.该方法可以根据板上测点功率谱图中共振峰的数量和基频大小（分析频带0-1 000 Hz）,对脱空状态进行初步定量判别;结合定量激励下测点振幅拟合曲线斜率的变化,实现脱空区边界的识别.通过若干不同脱空状态路面板的模型试验和对实际混凝土路面的检测,阐述了它的检测原理和操作流程,并验证了其可行性和有效性.

In order to develop a special instrument for the detection of voids beneath a concrete pavement slab,cut down detection cost and simplify detection process,a transient impulse response method was proposed based on the analysis of the existing detection methods and the changes in the frequency and amplitude of plates with voids under a quantitative excitation.With this method,the bearing state of a concrete plate,with or without voids,can be verified preliminarily quantitatively from the number of resonance peaks and the value of the foundation frequency in the power spectrum density（PSD） curves（with a band extent of 0 to 1 000 Hz）,and the boundary of a void can be detected based on the slope of the fitting curve of amplitude data.In order to expound the detection principle and process of the method,model plates with different cavity states were tested,and the bearing state of some real concrete pavement slabs were detected.The tested and detected results verify the validity and feasibility of the proposed method.