1. Sub-base layer with less proportion of ______ will help in serving as a better drainage layer.
a) Coarse aggregates
b) Fine aggregates
c) Cement
d) Crushed slag
Explanation: For drainage to take place properly, there must be sufficient gap or void space available for the water to flow. This is possible only when coarse aggregates are in a higher proportion than the fine aggregates.
2. Base course can prevent subgrade soil movement caused due to ______ in rigid pavement.
a) Shoving
b) Depression
c) Weathering
d) Slab pumping
Explanation: Slab pumping is caused when the loads deflect the slab. In pumping, materials come out from the subgrade through the cracks. The base course helps in preventing the movement of the subgrade soil by restricting the slab pumping.
3. Resilient modulus is the relevant strength parameter for granular sub-base.
a) true
b) false
Explanation: Resilient modulus is the ratio of stress to strain for rapidly applied loads. As per IRC 37:2012, the strength parameter for sub-base is taken as the resilient modulus.
4. By which technique can the existing pavement be reused in the sub-base as well as the base course?.
a) Reclamation
b) Asphalt recycling
c) Cold recycling
d) Hot recycling
Explanation: Cold recycling is a process by which the existing flexible pavement can be broken down into a reusable form. There are specific plants for carrying out this process. Hot recycling is used for rehabilitation of damaged flexible pavements.
5. Based on the strength property, the coarse aggregates can be classified into ____________
a) Hard and soft
b) Strong and weak
c) Resistant and non-resistant
d) Robust and non-robust
Explanation: The coarse aggregates are classified into hard and soft aggregates based on their strength property. Hard aggregates are used for superior quality roads and soft aggregates are used for low volume roads.
6. Which of the below represent the size range of medium gravel?
a) 2mm to 4mm
b) 8mm to 16mm
c) 4mm to 8mm
d) 16mm to 64mm
Explanation: Gravel size ranges from 4mm to > 256mm. There are fine, medium and coarse gravel types. The fine gravel ranges from 4mm to 8mm, medium gravel ranges from 8mm to 16mm and coarse gravel from 16mm to 64mm.
7. Which of the below is not an index to define the shape factor of stone aggregates?
a) Elongation index
b) Angularity number
c) Flakiness index
d) Group index
Explanation: Group index is a parameter that is used in the design of flexible pavements. All other options are indices that indicate the shape factor of aggregates.
8. Hardness indicates the strength requirement of an aggregate.
a) true
b) false
Explanation: Hardness is a property that gives a measure of resistance against abrasion. Strength is another property of the aggregate.
9. If the pavement is subjected to a prolonged period of water, then ______ of bituminous binder takes place.
a) Scraping
b) Skinning
c) Stripping
d) Striking
Explanation: Stripping of bituminous binder means that the bitumen coated on the aggregates comes off. This happens when it is subjected to water for a long period of time.
10. How are most of the road aggregates prepared?
a) Recycling
b) Crushing natural rock
c) From river bed
d) Manufactured
Explanation: Most of the road aggregates used are obtained by crushing natural rocks. Gravel aggregates are small rounded stones usually obtained from river beds, but it is not a common method.