UPSC Prelims 2020 Question:

In rural road construction, the use of which of the following is preferred for ensuring environmental sustainability or to reduce carbon footprint?

1. Copper slag 
2. Cold mix asphalt technology 
3. Geotextiles
4. Hot mix asphalt technology 
5. Portland cement
   
   

Select the correct answer using the code given below:

Explanation:

• The usage of Copper slag reduces the usage of primary materials as well as reduces the construction depth which in turn reduces energy demand in building. So, point 1 is correct.
  
  
• Cold asphalt mix is made by combining unheated mineral aggregate with emulsified or foamed bitumen. Cold asphalt mix, unlike hot mix asphalt (HMA), does not require aggregate heating. It makes it cost-effective and lowers pollution. So, point 2 is correct and point 4 is not correct.
  
  
• Geotextiles reinforces the soil by adding tensile strength to i. It is used as a rapid de watering layer in the roadbed. So, point 3 is correct.
  
  
• Portland cement production is energy intensive and can impact the environment. So, point 5 is correct.
  
  

Therefore, option (1) is the correct answer.

Subject: Environment| Sustainable Development