Application of Lock-In Thermography for Detecting Leakage Defects in Historic Masonry Arch Structures

Abstract

Defects in masonry are difficult to detect with the naked eye. Non-destructive testing (NDT) techniques are one such ways to detect defects. One way to detect moisture is by using lock-in Infrared (IR) thermography technology. The main objective of this research is to detect a defect in masonry brick walls using infrared thermography camera. Infrared thermography tests were conducted in the laboratory on several experiments to understand time and temperature relationships. Tests were conducted on a masonry water tank with a known defect spot and were successfully detected from the thermography images. Two active approach methods were conducted: halogen lights and a heat gun. It has been shown that when using the heat-gun it is a quicker method according to the results. All procedures and methods performed in this report could be useful for field studies.

Keywords

• infrared thermography
• non-destructive defect analysis
• masonry
• historic structures
• defects
• image processing
• active thermography