套筒灌浆密实度直接冲击振动检测方法

来源期刊:中南大学学报(自然科学版)2021年第3期

论文作者:王奎华 郑茗旺 涂园 项驰轩 刘鑫 谭婕 RIZVI Faheem 杨学林 余亚超

文章页码:848 - 859

关键词:灌浆密实度检测;钢筋套筒;直接冲击振动法;装配式建筑;定量判断

Key words:detection of grouted compactness; rebar sleeve; direct shock vibration method; prefabricated building structure; quantitative judgment

摘    要:装配式建筑结构一般由多个预制构件,通过钢筋套筒灌浆连接形成。然而,目前工程上对套筒内的灌浆密实度还没有可靠的检测和分析判断方法。本文设计一种带有全桥应变片的装置,可对套筒内钢筋产生短脉冲激振,然后对振动信号的时域和频域进行分析,从而实现对套筒灌浆密实度的定性及定量判断。结合室内原型试验,分析不同灌浆密实度的钢筋套筒受冲击后的振动信号,研究冲击信号时域曲线中的波峰幅值 、半峰全宽 和峰宽比 以及频域信号曲线中的峰值频率 等特征参数的变化规律。研究结果表明:随着套筒灌浆密实度n增加,冲击信号的时域曲线衰减速率增大,包括波峰幅值 、半峰全宽 和峰宽比 等特征参数也均随之增大;随着套筒灌浆密实度n增加,冲击信号的频域曲线的峰频率 趋于减小;对于未知灌浆密度的套筒,将冲击信号所得的峰宽比 或峰频率 代入曲线拟合的计算公式,可直接计算套筒灌浆密实度n,从而实现灌浆密实度的定量判断。

Abstract: The prefabricated building structure was generally formed by several prefabricated components through grouted rebar sleeves. However, there were no reliable method for detecting and analyzing the grouted compactness in the sleeve at present. The device with full Wheatstone Bridge of strain gauges was designed in this paper, which could exert the rebar in the sleeve are vibration with a short-duration''''s pulse. By analyzing the vibration signal in time-domain and frequency-domain, the qualitative and quantitative analysis of grouted compactness in the sleeve could be realized. Based on indoor prototypes'''' tests, the vibration signals of the rebars inside the sleeves with different grouted compactness were analyzed after the pulse. The indicators'''' characteristics from the time-domain signals curves were studied to find out the developing laws, including peak amplitude , full width at half maximum (FWHM) and peak-to-FWHM ratio . The indicator''''s characteristic from the frequency-domain signals curves were studied to find out the developing law, including peak frequency . The results show that with the increment of grouted compactness n, the attenuation rate of time-domain curves increases. When the grouted compactness n increases, values of indicators'''' characteristics increases, including peak amplitude , FWHM , and peak-to-FWHM ratio . Whereas the value of peak frequency from frequency-domain''''s curve tend to be smaller, as grouted compactness n is larger. For any sleeve with unknown grouted compactness, the peak-to-FWHM ratio or peak frequency extracted from the vibration signals can be directly calculated by curve fitting to find out the grouted compactness n. So the method can make it possible to quantitatively judge grouted compactness.

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