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UNIVERSITY OF GAZIANTEP FACULTY OF ENGINEERING CIVIL
DEPARTMENT
CE-550
NONDESTRUCTIVE TESTING AND EVALUATION IN STRUCTURAL ANALYSIS
Report About :
(The Using and application of REBAR DETECTOR test as anon
destructive test method in structural engineering)
Submitted to:
Do.Dr.ESSRA GUNAYISI
Prepared by: Chalak Ahmed Mohammed
[email protected]
2014 45056
Date: 20.03. 2015
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Introduction
It is used for detecting location and size of the reinforcement,
and the
concrete cover. This instrument is also known as rebar locator.
The
method is based on measurement of the change in electromagnetic
field
caused by the steel embedded in the concrete. It is covered by
BS
4408:1969-Part1. The device is a portable and handy
instrument,
normally used to locate the reinforcement, with an electronic
display.
To ensure satisfactory working of profometer and to get accurate
results,
it should be calibrated before starting the operations and at
the end of the
test. To check the calibration accuracy, the size and cover of
the
reinforcement of the test block is measured at different
locations on test
block and the recorded data should match with the standard
values
prescribed on the test block. Path measuring device and spot
probes are
together used for path measurements and scanning of
reinforcement bars.
These are connected with profometer and are moved on the
concrete
surface for scanning the reinforcement bars and measuring the
spacing.
Diameter and depth probes are used in conjunction with the
profometer
to measure the diameter of rebar and its concrete cover
respectively For
carrying out this test, proper access to the test section is
essential. Before
actual scanning, marking is done with chalk on the concrete
surface by
dividing it into panels of equal areas. The method is very fast
and gives
quite accurate results if the reinforcement is not heavily
congested. The
equipment is light and a single person can perform the test
Also in order to reduce the damage to the old reinforced
concrete walls
and work out the best construction scheme during the
renovation
of old buildings, it is often required to detect the position of
rebar buried
in concrete walls. In this paper, we propose a
non-destructive
method to detect the buried rebar by self-inductive sensor
combined with
surface acoustic wave resonator
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PROFOMETER REBAR DETECTION
The measuring method is based on the eddy current principle
with
pulse induction. The basic unit can perform the functions such
as:
(i) locating rebars,
(ii) measuring concrete cover,
(iii) storing individual cover values and statistical
evaluation, and (iv)
determining the bar diameter. It measures more accurately cover
in
the range of 60 mm 150 mm, and bar diameter in the range of
10
26 mm with bar spacing in the range of 70 mm 200 mm.
The instrument has Neighboring bar correction and 2-Layer
correction
facility. Neighboring bar correction mainly used for
determination of
the bar diameter in close spaced parallel bar arrangements.
2-Layer
Correction mode helps in congested standard orthogonal bar
arrangements. The congested bars induce a too strong
measuring
signal which can be corrected
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OBJECTIVES OF PROFOMETER REBAR DETECTION
For measurement of concrete cover.
To find the diameter of bars in the concrete.
To find the spacing between the bars
Location of moisture variations. Location of voids. Localization
and the dimensions of voids.
Type of Rebar Detection
To allow certain constructions and to strengthen the concrete
rebars are cast
into it. Drilling through those reinforcing bars is a costly
business that can
be dangerous: Hitting a rebar while boring into the reinforced
concrete can
destroy the drilling instrument and can severely weaken the
concrete
structure. An instrument for rebar detection that quickly and
accurately
determines the location of the reinforcing bars in the concrete
will
significantly decrease construction time and costs.
The rebar detection instrument Profoscope has a unique
real-time
visualization mechanism, allowing the contractor to actually see
the
location of rebars beneath the concrete surface. The Profoscope+
features
data storage for automatic collection of data to make rebar
detection more
efficient
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MECHANISM
A rebar detector works on the principle that the steel within
the concrete will be affected by a magnetic field that is applied
by the
detector.
By assuming a set magnetic property for all steel reinforcing
bars and using a given bar size, the detector can predict the depth
and location
of the reinforcing bars.
The signal received will increase with increasing bar size
and
decrease with increasing cover.
To locate the bar position, the distance to the bar is
minimized,
indicating that the rebar detector is directly over a piece of
the
reinforcing steel.
Regards...
