NON-DESTRUCTIVE TESTING IN CIVIL ENGINEERING

G.V.Manoj KumarU.Maadaswamy

RMK ENGG. COLLEGE

OBJECTIVEAssessment of existing structure for rehabilitation

planningDetection of cracks, voids and other imperfections in the

materialMonitoring changes in the concrete with the passage of

time

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

Difference between:Destructive testing Non-destructive

testingCarried out until specimen’s

failurewill 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

NDT-methodsVisual inspection(VI)Liquid (dye) penetrant testMagnetic particle inspection(MI)Ultrasonic testing Radiography(X-ray)Schmidt rebound hammer

Visual inspectionOldest non-destructive testing method

can successfully detect the unacceptable surface discontinuities

cheap and reliable testing method

Liquid (Dye) penetrant testTo 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

Magnetic particle inspectionUsed 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

Magnetic flux concentration

Ultrasonic testing Detect both internal and

surface defect in sounding conducting material.

Any change in acoustic impedance produces ultrasonic reflection or echo

Ultrasonic testing is done for the concrete

ULTRASONIC TESTING MACHINES

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

Radiography test on a concrete beam

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.

Procedure of the test

Suitability of testingUltrasonic testing-sub surface, interstitialMagnetic particle inspection-surface, sub surface

discontinues Dye penetrant test-surface-breaking defects in all non-

porous materialsRadiographic testing-surface, sub-surface defects

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.

Uses of NDTFlaw Detection and EvaluationLeak Detection Location DeterminationDimensional Measurements Structure and Microstructure Characterization Estimation of Mechanical and Physical Properties

ConclusionNon-destructive testing is not only

economical but gives very unique results

Involves very less time when compared to universal testing machine

“KNOWING IS NOT ENOUGH, WE MUST APPLY

WILLING IS NOT ENOUGH, WE MUST DO”

Thank

you!!!