Highway Materials MCQ with answer and solution

Concept

Use of Plastic Waste in Bituminous Mixes

Formula

N/A

Step-by-step solution

1. Evaluate statement 1: Plastic waste increases the softening point of bitumen, improving heat resistance. 2. Evaluate statement 2: Plastic coating improves bonding and prevents water-induced stripping. 3. Evaluate statement 3: Substituting virgin bitumen with plastic waste reduces construction costs. 4. Conclude that all three statements are correct, making Option (d) the correct answer.

Explanation

All three statements are correct:1. Adding plastic waste raises the softening point of bitumen, making the road more resistant to heat and preventing it from melting or deforming during hot weather. 2. The plastic coating improves the bonding between bitumen and aggregates, preventing water from seeping in and stripping the bitumen off. 3. Replacing a portion of the bitumen with recycled plastic reduces the amount of expensive virgin bitumen needed, making road construction more economical.

Shortcut

To remember the benefits of plastic waste in bituminous roads, use the mnemonic "SSR": - Softening Point: Increases softening point for better heat resistance. - Stripping Resistance: Enhances bonding to prevent water damage and stripping. - Save Bitumen: Reduces virgin bitumen needed, lowering overall cost.

Common mistake

A common mistake is selecting option A by assuming plastic waste only improves mechanical properties (softening point and stripping resistance) while overlooking its cost-saving benefit from substituting virgin bitumen. Another frequent error is choosing option B or C by doubting whether plastic coating actually enhances water resistance or increases the softening point.