This set of Pavement Design Multiple Choice Questions & Answers (MCQs) focuses on “Components of Pavement”.
1. Flexible pavement consists of ______ course after subgrade course.
a) Grade course
b) Base course
c) Sub-base course
d) Binder course
Explanation: Typical layers of a flexible pavement include subgrade as the bottom-most layer, then there is a sub-base course, base course, binder course, and surface course. There is no layer as a grade course in a pavement.
2. Which of the below is not a purpose of providing a prime coat?
Explanation: The prime coat provides adhesion between the base course and bituminous course. The purpose of providing prime coat includes coating and bonding loose materials, to harden or toughen the base surface and to plug the capillary voids.
3. It is important to ensure that the subgrade is not ______ at any time.
c) Over compacted
Explanation: it is necessary that the subgrade is not overstressed at any point in time. It means that the stress from wheel loads should be within the allowable limits. Otherwise, there would be cracks that would eventually lead to complete pavement failure.
4. Frost protection layer is provided in between which layers?
a) Surface and base course
b) Sub-base and base course
c) Subgrade and sub-base course
d) Surface and sub-base course
Explanation: Frost protection layer is a special type of protective layer that is provided in pavements constructed in colder areas. It is provided between the sub-base course and subgrade soil. It is used to protect the pavement from frost heaves.
5. Within what temperature range should the tack coat be applied?
a) 30 – 40°C
b) 20 – 50°C
c) 34 – 44°C
d) 24 – 54°C
Explanation: 24 – 54°C is the right temperature range within which the tack coat is to applied to the pavement layers. If the temperature is very high then the tack coat will break and it would be difficult to apply it. Breaking of tack coat implies the evaporation of water from the emulsion.
6. What is the thickness of the binder course that is provided in the pavement?
a) 50 – 100 mm
b) 100 – 200 mm
c) 25 – 50 mm
d) 100 – 150 mm
Explanation: The general practice is to provide 50 – 100 mm thick binder course. When the economic factor is not a constraint, then the thickness can be increased to 100 – 150 mm. The surface course is generally laid as 25 – 50 mm thick layer.
7. What type of surface course is provided in a semi-rigid pavement?
Explanation: Semi-rigid pavements are intermediate pavements in between flexible and rigid pavements. The surface course for semi-rigid pavement is provided as a flexible surface course because the materials used for semi-rigid pavements have a low impact and abrasion resistance.
8. Acrylic sealer is preferred to fast dry sealers.
Explanation: There are two types of sealers used – acrylic and fast drying in the seal coat. Acrylic sealers are eco-friendly but are very expensive. Fast dry sealers are used for foot traffic or low traffic and may deteriorate earlier. So, acrylic sealers are preferred.
9. Which of the below doesn’t represent the purpose of providing a base course in the rigid pavement?
a) Prevent pumping
b) Carry load
c) Resist frost
d) Slab settlement
Explanation: The primary purpose of providing a base course in rigid pavement is not to carry the load. The concrete slab can be used as surface and base course as it has sufficient strength. Placing it directly over subgrade might result in damage due to frost, slab displacement, and pumping.
10. Boulders are preferred in the construction of the base course because of their strength.
Explanation: Boulders are not preferred because of their large size and poor interlocking. The lack of interlocking would be detrimental to the long life of the pavement. The boulders might project outside, sink into the soil when wet and cause trouble.
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.