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
- Portland cement Select the correct answer using the code given below:
Correct Answer: Option A
The use of waste materials is gaining importance in road construction due to disposal issues, environmental concerns, and the depletion of natural resources. Byproducts like biomass ash, coal ash, red mud, and copper slag can be used in roads, buildings, and bridges.
Option 1 is correct: Using copper slag in cement and concrete offers environmental and economic advantages, particularly where copper slag production is high.
Option 2 is correct, and Option 4 is incorrect: Cold mix asphalt involves mixing unheated aggregate with emulsified or foamed bitumen. Unlike hot mix asphalt (HMA), it doesn't require heating, making it more economical and less polluting (no fumes or odors). It's also suitable for remote areas and can be used for both new construction and recycling asphalt pavements.
Option 3 is correct: Geotextiles are commonly used in road construction to fill gaps and improve soil structure. They help prevent soil erosion while allowing water drainage, enabling construction in difficult terrains.
Option 5 is not correct: Producing Portland cement is energy-intensive and releases significant amounts of carbon dioxide (CO2) and other pollutants.
Therefore, options 1, 2, and 3 are preferred for environmental sustainability in rural road construction.
Hence, option a is the correct answer.