Highway Construction MCQ with answer and solution

Concept

Compaction equipment suitability for granular soils

Formula

NONE

Step-by-step solution

1. Analyze soil type: dry cohesionless granular material (sand, gravel). 2. Granular soils have no cohesion and compact best under dynamic vibration and cyclic shearing. 3. Vibratory rollers produce high-frequency vibrations that eliminate interlocking friction, allowing particles to slide into voids. 4. Sheepsfoot rollers are used for cohesive clays, and rammers are for confined spaces. 5. Therefore, vibratory roller (option A) is the most suitable equipment. Answer: A

Explanation

Vibratory rollers are the most effective compaction equipment for dry, cohesionless granular materials such as clean sands and gravels. The mechanical vibrations reduce internal inter-particle friction, allowing gravity and dynamic forces to rearrange granular particles into their densest packing state.

Why the other options are wrong

B) Sheepsfoot rollers compact cohesive clayey soils via kneading pressure. C) Rammers are intended for confined trench backfill, not broad highway compaction. D) Watering alone cannot produce required compaction energy for granular bases.

Shortcut

Vibration for Granular (Sand/Gravel); Kneading (Sheepsfoot) for Cohesive (Clay).

Common mistake

Selecting Sheepsfoot roller, which relies on kneading action and tamping feet that are only effective on cohesive clays.