1. In charpy test specimen, the angle of v-notch section is ____________
a) 30 degrees
b) 45 degrees
c) 60 degrees
d) 90 degrees
Explanation: In charpy test specimen, the angle of v-notch section is 45 degrees and 0.25mm radius along the base.
2. The slump would not exceed 50 mm when compacting concrete with vibrators.
a) True
b) False
Explanation: Segregation means concrete cement slurry & fine aggregates &coarse aggregate collapsed & have no slump & after hardening no strength but workability is the checking the concrete how much time used after mixing.
3. When vibrators are used for compaction, the consistency of concrete depends upon the ___________
a) Type of mix
b) Efficiency of vibrator
c) Placing conditions
d) Type of mix, efficiency of vibrator, pacing conditions
Explanation: When vibrators are used for compaction, the consistency of concrete depends upon the Type of mix, efficiency of vibrator, pacing conditions.
4. Which of the following statement is correct while compacting concrete with vibrators?
a) The vibrator should be inserted horizontally
b) The vibrator should not be immersed through a full depth of freshly laid concrete
c) The vibrator should not touch the form surface
d) The vibrator should touch the form surface
Explanation: If there is a considerable amount of time lapse between the placements of subsequent lifts, it may be necessary to re vibrate the previous lift prior to placing additional concrete to minimize the potential for pour lines and cold joints.
5. The levelling operation that removes humps and hollows and give a true, uniform concrete surface is called ____________
a) Screeding
b) Floating
c) Troweling
d) Compacting
Explanation: The levelling operation that removes humps and hollows and give a true, uniform concrete surface is called Screeding.
6. The final operation of finishing the concrete surface is called _____________
a) Screeding
b) Floating
c) Troweling
d) Compacting
Explanation: The final operation of finishing the concrete surface is called Troweling.
7. The process of removing the irregularities from the surface of concrete left after screeding is called floating.
a) True
b) False
Explanation: The process of removing the irregularities from the surface of concrete left after screeding is called floating.
8. The process of hardening the concrete mixes by keeping its surface moist for a certain period is called ____________
a) Curing
b) Floating
c) Troweling
d) Compacting
Explanation: The process of hardening the concrete mixes by keeping its surface moist for a certain period is called curing.
9. After the curing of 28 days, the concrete gains strength upto _____________
a) 40%
b) 60%
c) 80%
d) 100%
Explanation: After the curing of 28 days, the concrete gains strength upto 100 percentage.
10. The construction joints in cement concrete ___________
a) Should be located where bending moment is large
b) Should be located where shear force is large
c) Should not be provided at the corners
d) Should be spaced at a distance of 3 m apart in case of huge structures
Explanation: The construction joints in cement concrete should not be provided at the corners.