Development of Non-Destructive Inspection Technology for Preservation and Repair of Modern Structures Especially for Masonry

本文在无损检测方法方面的研究成果总结如下：1.回弹数法：进行了适用于砖试件的试验。结果表明，用长边面上的回弹数来估算砖的强度比用混凝土试件的估算要准确得多。此外，还考虑了试件的含水率，提高了精度。小尺寸芯材：进行了结构混凝土强度评定的基础性试验。结果表明，由于样本数的提高，小尺寸岩心的估计精度已经足够，解决了普通岩心存在的问题。颜色：对砂浆棒颜色的影响因素进行了实验探讨。结果表明，通过颜色的测量来估算弹性模量值是可能的。雷达：用时域有限差分法进行数值分析，验证了探测钢筋或空洞的可能性。此外，利用改进后的雷达对意大利维科堡教堂的加固和空洞进行了验证测试和检测。超声断层扫描：进行了实验和分析讨论。结果表明，声源角度校正和扫描线两个方向分离分析是有效的。磁致伸缩方法：进行了基础性实验。结果表明，砂浆的影响较小，考虑屈服应力、钢筋直径和钢筋深度的标定曲线显示了应力估算的可能性。

The results obtained in this research for non-destructive testing methods are summarized as follows :1. Rebound Number Method : The experiment applying for brick specimens was carried out. As the result, the estimation of strength of brick by reboulnd number on long side surface is more accurate than the estimation of concrete specimen. Moreover, the accuracy is improved with the consideration of moisture content of specimen.2. Small Size Core : The fundamental experiment for the evaluation of strength of concrete in structure was carried out. As the result, it is clarified that the accuracy of estimation by small size core is enough because of the improvement of number of specimen, solving the problems of ordinary cores.3. Color : The experimental discussion of influencing factors on color of mortar bars was carried out. As the result, the possibility of estimation of elastic modulus is shown by measurement of color.4. Radar : The possibility of detection of reinforcement or cavity was shown by the numerical analysis with finite difference time domain method. Moreover, using the improved radar, the validation test and detection of reinforcement and cavity at Vico Forte Church, Italy, were carried out.5. Ultrasonic Tomography : The experimental and analytical discussion was carried out. As the result, it is clarified that the correction with the angle of sonsors and the separation analysis of scanning lines into two directions are effective.6. Magnetostriction Method : The fundamental experiments were carried out. As the results, it is clarified that the influence of mortar is small, and the possibility of estimation of stress is shown by the calibration curves considering yield stress, diameter and depth of the reinforcing steel bar.