In rural road construction, the use of which of the following is preferred for ensuring environmental sustainability or to reduce carbon footprint?
- Copper slag
- Cold mix asphalt technology
- Geotextiles
- Hot mix asphalt technology
- Portlant cement
Select the correct answer using the code given below:
Detailed Explanation:
Answer: Option 1 — 1, 2 and 3 only
For ensuring environmental sustainability and reducing carbon footprint in rural road construction, copper slag (a by-product reducing natural resource demand), cold mix asphalt (lower temperature processing with reduced emissions), and geotextiles (synthetic materials minimizing excavation and resource use) are preferred. Hot mix asphalt requires high energy consumption, and Portland cement production is carbon-intensive, making them less environmentally sustainable choices.
✅ Statement 1 – Correct: Copper slag, a copper refining by-product, can replace sand in concrete, reducing sand mining and environmental impact.
✅ Statement 2 – Correct: Cold mix asphalt technology operates at lower temperatures, consuming less energy and emitting fewer greenhouse gases compared to hot mix.
✅ Statement 3 – Correct: Geotextiles provide soil stabilization and drainage while reducing the need for excessive excavation and natural resource consumption.
❌ Statement 4 – Incorrect: Hot mix asphalt technology requires high temperatures and thus higher energy consumption, making it less environmentally sustainable.
❌ Statement 5 – Incorrect: Portland cement production is highly energy-intensive and emits significant CO₂, contributing substantially to carbon footprint.
📝 Short Notes: Sustainable Road Construction Materials
| Material/Technology | Environmental Benefits | Carbon Footprint Impact |
|---|---|---|
| Copper Slag | By-product utilization; reduces sand mining; waste recycling | Low - diverts industrial waste |
| Cold Mix Asphalt | Lower production temperature (60-100°C vs 150-180°C); allows recycled materials; can be produced on-site | Reduced by 30-50% compared to hot mix |
| Geotextiles | Reduces excavation depth; improves soil stability; extends road life; reduces gravel/stone requirement | Low - reduces material transport and extraction |
| Hot Mix Asphalt | Good performance but high energy demand | High - requires 150-180°C processing |
| Portland Cement | Limited - energy-intensive production | Very High - 0.8-0.9 kg CO₂ per kg cement |
- Green Road Construction: Focus on using industrial by-products, recycled materials, and low-energy technologies
- Rural Road Context: PMGSY (Pradhan Mantri Gram Sadak Yojana) encourages use of sustainable materials and local resources
- Geotextiles Applications: Separation, filtration, drainage, reinforcement, and erosion control in road construction
- Fly Ash & Slag: Other industrial by-products increasingly used as sustainable alternatives in road construction
Question 1 of 3 Clean and Green Technologies
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