Abstract

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Title:: Qualitative detection and analysis for compactness of prestressed concrete duct grouting based on elastic wave

Author(s):: DAI Zhili1; XIANG Zhongfu1; LIU Shijian2; ZHOU Hui3; LUO Chao1; (1. School of Civil Engineering, Chongqing Jiaotong University, Chongqing 400060, China; 2. Guangxi TrafficScience Research Institute Co. Ltd， Nanning 530000, Guangxi, China; 3. School of Architecture andUrban Planning, Chongqing Jiaotong University, Chongqing 400060, China)

Keywords:: bridge engineering; prestressed concrete; duct grouting compactness; qualitative detection; elastic first wave

Abstract:: In order to improve the detection accuracy, the prestressed concrete duct grouting qualitative detection around a 20 meters long model beam was researched. Firstly, an onedimensional propagation model for the first elastic wave in the grouting duct by reasonable simplification was established, then a linear formula for the first elastic wave slowness and duct grouting compactness was proposed. Secondly, according to the propagation model, a 20 meters long model beam which include 5 ducts with different grouting compactness were built. The elastic excitation and acquisition devices were used to detect the duct grouting qualitatively by cycle sampling method. The sampled data, calculated the first wave slowness by first wave position automatic judgment algorithm and optimal filtering parameter selection method were processed. Finally, the linear formula to calculate the duct grouting compactness was used, compare with the result of the design value. The results show that the first elastic wave and the duct grouting compactness are nearly linear relationship, the relative error is 5% more or less. The cycle sampling, first wave position automatic judgment algorithm and optimal filtering parameter selection method can be used to detect the compaction of prestressed concrete duct grouting, and improve detection accuracy. 1 tab, 11 figs, 31 refs.