This set of Pavement Design Multiple Choice Questions & Answers (MCQs) focuses on “Highway Maintenance – Rehabilitation of Rigid Pavement”.
1. Which of the below failures in rigid pavement does not require a full-depth repair?
a) Transverse cracks
b) Shattered slabs
c) Corner breaks
d) Shrinkage cracks
Explanation: Shrinkage cracks are hairline cracks that do not extend in the whole slab. It will not require a full-depth repair. Transverse cracks, shattered slabs and corner breaks are the defects in the rigid pavement that require full-depth repair.
2. ______ is done after identifying the repair limits in the FDR method.
a) Removal of slab
b) Drill holes
c) Saw-cut the perimeter
d) Removal of the damaged base
Explanation: There are certain set steps to be followed when conducting the FDR for rigid pavements. The first step is to identify the repair limits. Then the perimeter needs to be saw-cut to understand the area of repair. Then removal of slabs, damaged base, drilling holes for reinforcements, providing reinforcement, placing and finishing concrete and finally restoring the existing joints.
3. How is the delamination in the rigid pavement identified to conduct repair works?
a) Sound test
b) Lab testing
c) Profile checking
d) Destructive testing
Explanation: The delamination on the rigid pavement can be identified using a simple field test – the sound test. Steel rebar or hammer is tapped near the spalls and if the sound is solid, there is no delamination. If not, then the repairs are to be made.
4. A CC pavement has sufficient structural strength and no significant distress. But it has insufficient thickness. What rehabilitation strategy is to be used in this case?
a) Bonded asphalt overlay
b) Hot mix asphalt overlay
c) Bonded concrete overlay
d) Cold mix asphalt overlay
Explanation: Most of the pavements designed years ago might not be sufficient to serve the present traffic. They might be structurally sound and have little or no defects. Their thickness is what needs correction or increment. Bonded concrete overlay is the fastest and cheapest option in this case.
5. Shotblasting is a method used to ______ the surface of the rigid pavement.
Explanation: The existing surface of the pavement needs to be scarified and roughened to receive the new surface. It can be done by using shotblasting, cold milling or sandblasting. Shotblasting uses compressed air to shoot steel balls on the pavement and scarify it.
6. In CPCD pavements, the stitching method is most useful for transverse cracks.
Explanation: In CPCD pavements, the method of rehabilitation using stitching is not preferred for transverse cracks. If done, it might lead to the build-up of stress due to the changes in volume because of variation in temperature.
7. Which of the below is not a type of stitching used in the rigid pavement?
a) Slot stitching
b) V-bar stitching
c) Cross stitching
d) U-bar stitching
Explanation: Stitching in rigid pavements can be done in three ways – slot stitching, cross stitching and U-bar stitching. Cross stitching is used for fairly tight cracks, slot stitching for wider cracks and the U-bar stitching for removing concrete and anchoring by U bars.
8. Which rehabilitation method is effective when the faulting is severe?
a) Dowel bar retrofitting
b) Transverse joint fixing
c) Tie bar retrofitting
d) Longitudinal joint fixing
Explanation: The faulting defect occurs when there is no dowel bar provided and the level of joints is varying a lot. When this defect becomes severe, rehabilitation is required and dowel bar retrofitting is the best possible method. The concrete slab is taken out, dowel bars are placed and then resealed with concrete.
9. Which of the below defects cannot be rectified by using the diamond grinding method?
Explanation: Diamond grinding is a method that is primarily used to correct the level of the pavement. It uses closely spaced diamond blades to grind the pavement surface and it is an expensive method. Defects like roughness, skidding, noise and bumps can be rectified. Sags are not common in rigid pavements and cannot be ground.
10. HMA overlays in the CRCP pavements have been successful in the treatment of ______
c) Corner cracks
Explanation: Hot mix asphalt overlay can be provided on top of CRCP pavements to treat loss of skid resistance and punchouts. It has been found to give great results to treat punchouts. This is attributed to the presence of a smooth surface which reduces the dynamic loads from trucks when riding on a rough surface.
11. The method of diamond grinding reduces the thickness of the pavement and might prove to be a reason for the reduced load-carrying capacity.
Explanation: Diamond grinding indeed grates the pavement surface and reduces the thickness of the pavement. The depth of diamond grinding is from 2.54 mm to 6.35 mm. Since the pavements are designed with extra thickness for future traffic, the method doesn’t essentially reduce the load-carrying capacity.
12. The performance of an unbonded concrete overlay depends on the thickness and quality of ______
a) Existing surface
d) Base course
Explanation: In the unbonded concrete overlay, a concrete overlay is placed over an existing pavement with an interlayer between them to break the bond. The performance of the unbonded concrete overlay depends on the thickness and the quality of the interlayer.
13. Which method cannot be used in CRCP type rigid pavement?
a) Dowel bar retrofitting
c) Bonded concrete overlay
d) Diamond grinding
Explanation: The dowel bar retrofitting method can only be used in the CPCD and not CRCP type rigid pavement. Load transfer by the joints affects CPCD pavement performance. The dowel bar helps in the effective load transfer at joints.
14. In CPCD pavements, the joint repair can be done by ______
c) FDR and HDR
Explanation: In the case of CPCD pavements, both the FDR and HDR rehabilitation techniques can be used for joint repair. Depending on the extent of breaking or spalling of the joints, the rehabilitation technique of full-depth repair or half-depth repair can be chosen. In CRCP pavement, only FDR can be done.
15. Which code is used for guidelines on the rehabilitation of rigid pavements?
a) IRC 83:2012
b) IRC 83:2008
c) IRC SP 83:2008
d) IRC SP 83:2012
Explanation: IRC SP 83:2008 is the code referred to for the guidelines regarding the maintenance, repair, and rehabilitation of rigid pavements. The SP stands for special publication. IRC 83 gives the code of practice for road bridges.
Sanfoundry Global Education & Learning Series – Pavement Design.
To practice all areas of Pavement Design, here is complete set of 1000+ Multiple Choice Questions and Answers.