Relevance: GS III (Infrastructure / Science & Tech) | Source: The Hindu

1. What is the News?

• The Failure: Under the Pradhan Mantri Gram Sadak Yojana (PMGSY), 42 roads were built in Arunachal Pradesh using advanced nanotechnology. Shockingly, 37 of these roads (~88%) have already failed.
• The Official Reason: The state government admitted that the technology, while advanced, could not handle the extreme rain and unstable soil of the Himalayan mountains.

2. How do Nanotechnology Roads Work?

• Water-Repellent (Hydrophobic): Traditional roads soak up water, which causes potholes. Nanotechnology uses tiny particles to make the road surface hydrophobic—meaning it repels water like a lotus leaf.
• Molecular Glue: Nano-materials (like Nano-silica) act like a super-strong glue at a microscopic level, binding soil and gravel together to make the road much tougher than usual.

3. Why did they fail in Arunachal?

• Tough Terrain: The Himalayas are “Young Fold Mountains,” meaning the soil is still shifting and unstable.
• Heavy Monsoon: Arunachal receives some of the highest rainfall in India. The constant water pressure and landslides simply washed away the nano-treated layers.
• The Lesson: This failure teaches us that technology that works perfectly in the flat plains (like Delhi) may not be suitable for the hills without major changes.

UPSC Value Box

With reference to nanotechnology in infrastructure, consider the following statements:

1. The use of nanotechnology in road construction aims to make the soil and bitumen surface hydrophobic to prevent water seepage.
2. The Pradhan Mantri Gram Sadak Yojana (PMGSY) promotes the use of “Green Technologies” to make rural roads more durable and eco-friendly.
3. Nanotechnology-based roads are naturally more stable than traditional roads in high-rainfall, landslide-prone mountain terrains.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3