Question

Which one of the following methods is most commonly used to measure the thickness of asphalt in road construction?

• A. Weighing method
• B. Ultrasonic test
• C. Core drilling
• D. Visual inspection

Hint:

Core drilling is used to determine:
• Pavement thickness.
• Density.
• Layer quality. It is the standard quality control method for flexible pavements.

Answer 1

The Correct Option is C

Concept: The thickness of asphalt pavement is commonly determined by extracting cylindrical samples from the pavement. This method is known as \[ \boxed{\text{Core Drilling}.} \] The extracted core is measured directly for layer thickness and may also be tested for density and other quality parameters.

Step 1: Understand the method. A core cutter drills through the pavement and removes a cylindrical specimen. The thickness of each pavement layer is then measured accurately.

Step 2: Identify the commonly adopted method. Since direct measurement provides the highest accuracy, \[ \boxed{\text{Core drilling is the standard method for measuring asphalt thickness}.} \] Therefore, the correct option is \[ \boxed{(C)\;\text{Core drilling}.} \]