This document discusses the Schmidt Hammer as a nondestructive testing method for structural engineering. It provides an introduction to rebound hammers and how they are used to determine the strength and durability of concrete or rock. The components of the hammer are described including the impact spring, rider, window, housing, and hammer mass. The principles of the test are that the elastic mass depends on the surface hardness, which is related to compressive strength. The results can be affected by mix characteristics, angle of inclination, and member characteristics. The procedure involves testing against an anvil and taking the average of about 15 readings. Advantages are assessing likely compressive strength and quality, while limitations include surface smoothness and moisture conditions.

1. 1
Gaziantep University
College of Engineering
Civil Engineering Department
Report on
Schmidt Hammer as Nondestructive test
method in Structural Engineering
Submitted by
Mohammed Layth Abbas
Student No:201444956
Supervisor
Assoc.Prof. Esra Mete Güneyisi
CE 550
(Nondestructive Testing and Evaluation in Structural Eng)

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Introduction:
Rebound Hammer is a Non – Destructive Testing Instrument,
a simple and handy tool, which is used to determine or
measure the strength and durability of concrete or rock and
rebound hammer device is used on finished concrete
structures also. So is mainly used to know surface hardness
and penetration resistance. The Rebound Hammer can
deliver the literally accurate results.
Components of Hammer:


The schematic diagram showing various parts of a rebound
hammer as show in the fig (2)
1. Concrete surface
2. Impact spring
3. Rider on guide rod
4. Window and scale
5. Hammer guide
6. Release catch
7. Compressive spring

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8. Locking button
9. Housing
10. Hammer mass
Principles of the test:
The elastic mass depends on the hardness of the surface.
•It is related to the compressive strength of the concrete.
•The rebound value is designated as the rebound number or
rebound index.
•The results are significantly affected by :
A) Mix characteristics.
B) Angle of inclination of direction of hammer.
C) Member characteristics.

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Procedure of the test:
 Should be tested against the test anvil.
 Apply light pressure on the plunger and allow it to extend
to the ready position for the test.
 Apply a gradual increase in pressure until the hammer
impacts.
 Take the average of about 15 readings.

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Advantages:
 Assessing the likely compressive strength of concrete .
 Assessing the quality of concrete in relation to standard
requirements.
Limitation of the test:
 Smoothness of surface under test
 Size , shape and rigidity of the specimen
 Age of specimen
 Surface and internal moisture condition of the concrete
 Type of coarse aggregate
 Type of cement
 Type of mould

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 Carbonation of concrete surface
Interpretation of Results:
The rebound reading on the indicator scale has been calibrated
by the manufacturer of the rebound hammer for horizontal
impact.