Health detection techniques for historic structures

The protection of historic buildings has drawn increasing attention and usually requires a sound nondestructive testing (NDT) technique. This paper first describes the significance of and the status on the protection of historic structures followed by a summary of common damage and repair measures for such structures. Lastly, the principles, characteristics, and applications of NDT techniques for historic wooden and masonry structures, including ultra-CT testing, stress wave testing, micro-drilling resistance meter, radar detection, and X-ray diffraction, are described and compared. This study concludes by providing a guide for studying the structural damage of historic structures and for the selection of a detection technique.