This presentation provides info. on some of the basic NDT tests

1. G.V.Manoj Kumar
U.Maadaswamy
RMK ENGG. COLLEGE

2. OBJECTIVE
 Assessment of existing structure for rehabilitation
planning
 Detection of cracks, voids and other imperfections in the
material
 Monitoring changes in the concrete with the passage of
time

3. Non-destructive testing
 Is a form of testing to be carried out on various
construction members and materials without causing any
permanent damage to them.
 Does not permanently alter the article being tested

4. Difference between:
Destructive testing Non-destructive testing
 Carried out until specimen’s
failure
 will render the part unusable
for its intended purpose
 Does not destroys the test
specimen
 after testing, allow the part to
be used for its intended purpose

5. NDT-methods
 Visual inspection(VI)
 Liquid (dye) penetrant test
 Magnetic particle inspection(MI)
 Ultrasonic testing
 Radiography(X-ray)
 Schmidt rebound hammer

6. Visual inspection
 Oldest non-destructive testing method
 can successfully detect the unacceptable surface
discontinuities
 cheap and reliable testing method

7. Liquid (Dye) penetrant test
 To detect surface-breaking discontinuities in all non-
porous materials (metals, plastics, or ceramics).
 It is based upon the principles of capillary action
where liquid penetrates into a cavity.
 Fast, economical and widely used method

9. Magnetic particle inspection
 Used to detect defects on the surface or near to the
surface.
 Generate magnetic flux in article to be examined.
 The particles are often colored and usually coated with
fluorescent dyes that are made visible with a hand-held
ultraviolet (UV) light

11. Magnetic flux concentration

12. Ultrasonic testing
 Detect both internal and
surface defect in sounding
conducting material.
 Any change in acoustic
impedance produces ultrasonic
reflection or echo

13. Ultrasonic testing is done for the concrete

15. Radiography (X-ray)
 Radiography uses X-rays and gamma-rays to produce a
radiograph of a specimen
 shows any changes in thickness, defects (internal and
external)
 to obtain permanent image of surface and sub-surface
discontinuities

16. Radiography test on a concrete beam

17. Rebound hammer
 Measures the rebound of a spring-loaded mass
 hammer will hit the concrete and rebound is dependent
on the hardness of the concrete
 The Schmidt hammer is an arbitrary scale ranging from 10
to 100.

18. Procedure of the test

19. Suitability of testing
 Ultrasonic testing-sub surface, interstitial
 Magnetic particle inspection-surface, sub surface
discontinues
 Dye penetrant test-surface-breaking defects in all non-
porous materials
 Radiographic testing-surface, sub-surface defects

20. NDT- Benefits
 Sample -available afterwards for repeat or additional
tests.
 Enables further use of work piece.
 Provides cost benefits.
 Enables comparison to standard and established results.
 Enables maintenance of statistical data for future
interpretation.

21. Uses of NDT
 Flaw Detection and Evaluation
 Leak Detection
 Location Determination
 Dimensional Measurements
 Structure and Microstructure Characterization
 Estimation of Mechanical and Physical Properties

22. Conclusion
 Non-destructive testing is not only economical but
gives very unique results
 Involves very less time when compared to universal
testing machine