Nondestructive Testing and Evaluation​ in Structural Analysis​ Infrared Thermography​

1. Nondestructive Testing and Evaluation
in Structural Analysis
Infrared Thermography
Lecturer:
Prof. Dr. Esra Mete Güneyisi
December 2023

2. Introduction
• Infrared thermography is a technique that involves detecting and converting
infrared energy emitted by an object into temperature data, which is then
displayed as an image showing the temperature distribution.
• All objects with a temperature above absolute zero emit infrared radiation. The
amount and type of radiation depend on the object's temperature.

3. Detection of Infrared Radiation
• Infrared cameras, also called thermal cameras, are the primary tools used in
infrared thermography. These cameras have sensors that can detect infrared
radiation and convert it into an electronic signal.
• The electronic signals from the infrared camera are processed to create a thermal
image or video. In this image, different colors or shades represent different
temperatures. Warmer areas appear as brighter, while cooler areas appear darker.

4. Infrared thermography camera

5. Types of infrared thermography
•Passive: It relies on the natural heat emissions of objects or
structures. All objects with a temperature above absolute zero emit
infrared radiation, and passive thermography captures this radiation
without the need for an external heat source.
• Active: It involves the application of an external heat source to the
object or structure being inspected. The surface temperature response
is then captured by an infrared camera, revealing temperature
variations and patterns.

6. Uses of Passive IRT in Structures
Moisture Detection: Passive infrared thermography is effective in detecting
moisture within building materials. Moist areas tend to have different thermal
properties, causing temperature variations that can be captured by the infrared
camera.

7. Uses of Active IRT in Structures
Concrete and Structural Inspections: Active thermography is used to inspect concrete
and other structural materials for defects such as delamination, voids, and cracks. The
heat excites the material, and irregularities are detected based on variations in thermal
response.

8. The relevance of infrared thermography
in civil engineering
• Infrared thermography allows for non-destructive testing
of structures. It helps identify potential issues such as
moisture infiltration, insulation deficiencies, and structural
defects without the need for physical intervention or
damage to the structure.

9. Infrared thermography and Structural Inspections
• The application in concrete structures is mainly focused on the detection of
surface defects, porosity, cracks, damage assessment and, particularly in the
case of reinforced concrete bridges, in the detection of delamination and
voids.

10. b) Thermogram
Detection of delamination:
a) Digital photography

11. b) Thermogram
Application in bridge infrastructure:
a) Digital photography

12. Advantages and limitations
Infrared thermography can be applied over large distances, analyze and inspect large areas in
small time intervals, and provide easy results and quick interpretation; besides having a
simple instrumentation. In most cases, all it takes to observe thermal images are a
thermographic camera, the camera support and a video output.
Despite the many advantages offered by this technique in the inspection, the equipment may
be expensive and insensitive to detect the depth of defects and anomalies in the concrete. In
addition, the testing is highly influenced by environmental conditions, such as wind, solar
radiation, humidity and surface emissivity

13. Thank You
Prepared by:
Rouna Hami
220000888090