1) In case of Ultrasonic pulse velocity test, The
quality grading of concrete is expressed in.
1) 4
2) 8
3) 6
4) 2
Ans
is 4
2) In case of dense homogeneous and uniform concrete
The ultrasonic pulse velocity test gives
1) High velocity
2) Less velocity
3) No change in velocity
4) Very less velocity
Answer is a
high velocity. Because The ultrasonic pulse will take more time. To cross
across the dense and homogeneous concrete it will observe maximum obstruction.
3) Non-destructive test of ultrasonic pulse velocity
test is conducted on concrete and Pulse velocity measured in meter per second
is 2500 then the quality of concrete is
1) Excellent
2) Good
3) Medium
4) Poor or doubtful.
The answer is quality of concrete is poor or
doubtful.
|
Pulse
velocity in m/s |
Concrete
quality |
Quality
grading |
Approximate
compressive strength (N/mm2) |
|
V>
4500 |
Excellent |
I |
>45 |
|
V=3500-4500 |
Good |
II |
25-40 |
|
V=
3000-3500 |
Medium |
III |
10-20 |
|
V<3000 |
Poor
or |
IV |
<10 |
4) The approximate compressive strength of concrete
in case of second quality grading in ultrasonic pulse velocity test is
1) More than 45
2) 25 to 40
3) 10 to 20
4) less than 10.
Ans. is 25-40
5) Which of the following test is the easiest and
fastest way for detecting details of reinforcing bar.
1)Ultrasonic pulse velocity test
2)Rebound hammer test.
3) Rebar locator test
4) none of the above.
Ans is 3) Rebar locator test
6) In respect of rebar locator test, The signal
received will increase with increase in bar size but decrease with increasing
cover. This statement is right or wrong.
1) Right
2) Wrong
Ans is right.
7) Which of the following test depends upon the
electromagnetic field?
1) Rebound hammer test
2) Ultrasonic pulse velocity test
3) Rebar locator test
4) Crack detection microscope test
The answer is 3) Rebar locator test
8) When chloride reaches to rebar level then -------occurs.
1) Elongation.
2) Corrosion
3) Buckling
4) Bending
Answer is 2) Corrosion
9) Half-cell potential meter test is used for
measurement of
1) Electrical conductivity of the reinforcement
2) Electrical potential in the reinforcement
3) To know the pH Of the concrete
4) The quantity of chloride present.
Answer is 2)
Electrical potential in the reinforcement
10) The pH measurement can be done by
1) pH strips.
2) pH pencils
3) digital meters
4) all of the above.
Answer is all of the above.
11) Half cell potential meter test gives probable
percentage of
----------- in the reinforcement.
1) Chloride content
2) Corrosion
3) Bending of reinforcement.
4) None of the above.
Answer is 2) Corrosion
12) Half-cell potential method test is conducted and
the result of half-cell potential meter test shows the result of 300 then what
is the probable percentage of corrosion in the bar
1) 10%
2) 20%
3) 30%
4) 50%
Answer is 4) 50%
|
Half-Cell
Potential relative to Cu-Cu Sulphate reference electrode in (mv) |
Probable
% of corrosion |
Remark |
|
Zero |
0% |
No
corrosion |
|
Less
than 200 |
10% |
Corrosion
is at very early stage but no corrosion on the surface of the bars |
|
Between
200 to 350 |
50% |
First
sign of corrosion and will be visible on the surface of the bars. |
|
Above
350 |
90% |
Corrosion
is in notorious stage with evident corrosion sign on the bars and in some
cases on the concrete too. |
13) Which of the following factors affects the
result of ultrasonic pulse velocity test.
1) Quality of concrete
2) Nature of concrete surface
3) Age of concrete
4) All of the above.
Answer is 4) All of the above.
14) Which of the following test is conducted for
determining the width and depth of crack in the structure.
1)Chloride test.
2) Crack detection micro-scope test
3)Rebar locator test
4. NOTA
Answer is 2) Crack detection micro-scope test
For detailed explanation of above questions in simple Hindi Language, Pls watch the following video.
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