【作者】 鲁晶晶；

【导师】 朱宏平；

【作者基本信息】 华中科技大学 ， 防灾减灾及防护工程， 2007， 硕士

【摘要】 众所周知,强度是混凝土最主要的指标之一,加强混凝土质量监控和检测,保证混凝土质量,是建筑工程管理中的重要环节。然而,由于传统的立方块抗压强度试验的局限性,人们需要不断研究在原位检测条件下混凝土强度的非破损检测新方法。同时,为了适应当今快速施工的需要,利用早期强度预测混凝土后期强度也成为国内外工程学术界关注的重要课题。本文首先概述了传统混凝土抗压强度检测方法的研究状况,并指出它们的不足和难以解决的问题,介绍了近年来混凝土抗压强度无损检测的新方法,论述了各种方法的国内外研究进展。随之介绍了PZT阻抗法用于结构强度检测的基本理论,论文最后给出了基于PZT阻抗法的28天龄期内混凝土立方块抗压强度检测试验及其分析结果,验证了PZT阻抗法应用于混凝土强度检测的可行性。试验结果表明:在混凝土28天龄期内,PZT电导纳频谱曲线的峰值出现明显的漂移;随着混凝土龄期的增长,压电导纳曲线逐渐向峰值频率增大的方向移动;在混凝土8天龄期内,压电导纳曲线移动幅度较大,8天以后移动幅度相对较小。混凝土试块28天龄期内压电导纳的变化规律与破坏试验得到的混凝土立方块抗压强度的变化规律是一致的。分别利用导纳的实部和虚部建立了量化评价指标—均方差根指数对混凝土龄期内压电导纳进行分析,分析结果也呈现出与混凝土抗压强度一致的变化趋势。作为一种新的检测方法,压电阻抗法还处于发展阶段,各项研究成果还不成熟,今后还需对压电阻抗法在其他类型混凝土以及在不同养护条件下的应用作更深入的研究。此外对将PZT埋入混凝土内部进行混凝土初凝前的强度监测作进一步的研究。更多还原

【Abstract】 As known to all, the strength is one of the most important indicators of concrete. To strengthen concrete quality control and testing becomes an important part of building management. However, because of the limitations of the traditional cubes compression strength test, people continue to study on situ detection of structural concrete strength under different conditions using nondestructive testing method. Meanwhile, in order to meet the current needs of the rapid construction, predicting concrete late strength with early strength also becomes an important topic in academic fields.This thesis first outlines the research of the traditional detection methods of the concrete compression strength, points out their deficiencies and the issue difficult to resolve, then introduces new methods of nondestructive testing of concrete compression strength, discusses the research progress of various methods. The basic theory of PZT impedance method for the detection of structural strength is shown followed. Finally, based on the experimental results and analysis of the concrete cubes compression strength testing during 28 days using PZT impedance method, the effectiveness of PZT impedance method applying to the concrete strength testing is verified.Test results show that: the peak of PZT electric admittance spectrum curve turns out apparent drift during 28 days period. With the growth of age, piezoelectric admittance curve gradually moves on the direction of the peak frequency increased. Compared to the changes of the compression strength of concrete cubes in experiment, they have consistency, that is, the curve grows rapid before eight days, and then relative ease after eight days. When another parameter RMSD(root mean square deviation) is used to value the admittance of the real and imaginary parts, it also shows the same trend with the strength.As a new detection method, piezoelectric impedance method is still in the development stage, and the researches are not ripe yet. The application of piezoelectric impedance method in other types of concrete and under different curing conditions needs more in-depth research in the future. In addition, the monitoring of concrete strength before the initial setting needs further study with the PZT embedded in the concrete.更多还原