【作者】 陈正； 陈犇； 逄子超； 吴昌杰；

【Author】 CHEN Zheng;CHEN Ben;PANG Zi-chao;WU Chang-jie;College of Civil Engineering and Architecture, Guangxi University;

【机构】 广西大学土木建筑工程学院；

【摘要】 青藏高原的环境条件限制常导致混凝土出现密实性缺陷问题,如何对混凝土的密实性缺陷进行精确的无损检测是保障结构承载力及耐久性的关键。本文结合此前在西藏雅鲁藏布江藏木大桥与广西南宁实地开展的混凝土超声试验结果,基于不同气压下混凝土实体的超声波速计算模型,建立了以气压、水胶比为参数的混凝土实体部分超声波速计算模型;并进一步对混凝土在不同孔隙率、缺陷条件、骨料分布情况条件下的超声波速进行了计算分析。揭示了孔隙率及缺陷条件对混凝土超声波速的影响规律及机理。研究了骨料分布占比对混凝土超声检测结果的影响规律,建立了混凝土整体超声波速的多因素计算模型,并提出了基于超声波速的混凝土密实性统计分析方法,可以为实际工程中混凝土结构密实性的超声无损检测结果分析提供理论依据。更多还原

【Abstract】 The environmental conditions of the Qinghai-Tibet Plateau lead to the compactness defects of concrete oftentimes. The key to ensuring the bearing capacity and durability of structures is to carry out accurate non-destructive testing for the defects of concrete compactness. In this paper, based on the ultrasonic pulse velocity(UPV) calculation model of the concrete solid parts under different air pressures, the UPV calculation model of concrete solid parts with air pressure and water-binder ratio as parameters was established based on the results of the ultrasonic test of concrete in Tibet Yarlung Zangbo River Zangmu Bridge and Nanning, Guangxi.Furthermore, the UPV of concrete under different porosity, defect conditions, and aggregate distribution conditions were calculated and analyzed. The influence law and mechanism of porosity and defect condition on UPV of concrete were revealed. The influence of aggregate distribution ratio on ultrasonic test results of concrete was studied, a multi-factor calculation model for UPV of concrete is established, and a statistical analysis method of concrete compactness based on UPV, which can provide a theoretical basis for the analysis of the results of ultrasonic nondestructive testing of concrete structure compactness in practical engineering.更多还原