Sonic-IR imaging technique for detection of crack interfaces in cementitious materials

Abstract

Sonic-IR (Infrared) imaging technique was applied to detect defects of cementitious materials in the temperature rise of thermal imaging by ultrasonic excitation and infrared thermography on the target surface. It was investigated in this study to identify the fracture regions with cracks inside mortar and quantifying the epoxy resin filling situation at repaired crack in concrete. As the results, it was found that sonic-IR imaging technique can be utilized for detecting the fracture area and the crack propagation zone, although it is known that the technique is usually introduced for metals or composite materials which have high thermal conductivity. In particular, the shear fracture surface formed due to compressive stress could be detected as well as X-ray CT imaging. It was also enabled to quantitatively clarify the fracture progress with damage degree of mortar subjected to the compression stress and the epoxy resin injected depth at the simulated crack in concrete.