Hello guys, I am here to share my knowledge on Non-Destructive Testing (NDT). In this presentation, I tried to explain on the following topics: 1. why we use NDT (purpose)? 2. Condition Assessment of the Structures by Non-destructive Evaluation Techniques 3. Concrete Petrography Implications 4. Potential as a DiagnosticTechnique 5. Common Applications of Microscopy in Concrete Science and Technology 6. Thermographic (Infrared Thermal Imaging) With interesting pictures and much more... I put some effort to present in front of you. So, kindly if you find any mistakes feel free to text.

2. Condition Assessment of
the Structures
by
Non-destructive Evaluation Techniques

3. It can be used for the following:
 To test actual structure instead of representative cube sample
 As a quality control tool
 To assess the structure for various distressed conditions
 For damage assessment due to fire, chemical attack, impact, age, etc.
 To detect cracks, voids, fractures, honeycombs and weak locations.
 To monitor progressive changes in the properties of concrete,
reinforcement, etc.
 To assess overall stability of the structure.
 To monitor repair and rehabilitation systems.

4. Concrete Petrography
Implications
and
Potential as a Diagnostic
Technique

5. “Petrography” owes its origin to that branch of geological sciences which
deals with the expert narration of mineral and chemical composition of
rocks as well as their internal structure or texture.
 Transmission Light Microscope
 Fluorescent Light Microscopy
 Electron Microscopy

6. Polished section of Portland cement
clinker
Photomicrographs of thin sections of cores (in plane
polarized light mode) showing the cracked oxidized
pyrite grain at the surface region, and extension of
cracking and reddish brown iron oxide and hydroxide
oxidation products into the neighbouring paste. Field
widths of all photos are 5 mm.

7. Photomicrographs of thin sections of cores (in plane
polarized light mode) showing the gypsum crystals
(G) in air voids, paste and cracks in the altered and
carbonated paste.
Development of cracks around the aggregates and
in the cement matrix.

8. Common Applications of Microscopy in
Concrete Science and Technology
The potential of this technique is illustrated below :
• Fine and Coarse aggregates
• Type
• Quality
• Cement Aggregate Reactions (AAR)
• Concrete aggregate
• hydrated cement paste interface (transition zone)

9. • Cement Paste
• w/c ratio
• Degree of cement hydration
• Presence of relative quantities of mineral admixtures
• Cement paste content
• Total air void counting
• Size and spacing of air voids
• Entrained versus entrapped air
• Distribution of air voids

10. Thermo graphic
(Infrared Thermal Imaging)

11.  The objective of infrared inspections is to identify and
diagnose a wide variety of common building defects without
have to tear open roofs, walls, ceilings or other building
structures.
 Thermal imaging is also an important component to detect
moisture intrusion (leak detection) and diagnosis services.
A view of Thermal Imaging

12. Infrared thermography is a process by which infrared radiation
from an object can be measured or imaged using a special
type of digital camera which translates the infrared image of
the object (which is not visible to the human eye) into an
image on an LCD screen.
Floor heating system defects not detected

13. Wet wall instruction, impossible to see
with the human eye
Water intrusion was visible at the surface of finish
materials primarily at the darkened area in the corner

14. Problem is clearly visible during an infrared
inspection
Defects in pipeline not detected

15. The infrared imaging of the same area indicated that elevated moisture
levels are present in a much wider area along the dashboard and under the
floor.

16. The infrared picture identifies the exact place of a
problem in a water line.
Moisture intrusion detected with IR.

17. A hidden pressure line leak not spotted
Leakage easily spotted but clearly visible in IR

18. Image of the roof of a refrigerated building
Moisture intrusion into a hole detected by IR

19. For any mistakes and suggestions feel free to text here
Idamakanti.jaswanth@gmail.com