Introduction

• Exploration of sustainable alternatives to concrete structures.
• Potential of biomass products as a solution.

Resources on Planet Earth

• Types of Resources:
  • Renewable/Recyclable: Includes water, solar energy, and biomass.
  • Non-renewable: Limited and exhaustible resources.
• Resource Consumption:
  • Humans occupy 2% of the planet’s surface yet consume 75% of its resources.
  • Biomass remains the only non-exhaustible resource.

Historical Context of Material Dependence

• Increase in non-renewable resource dependence from 0% to over 95% in 6,000 years since 4500 BC.
• Environmental Impact:
  • Indiscriminate mining causes ecological damage and resource scarcity (e.g., river sand).

CONCRETE

Concrete is a composite building material made from:

1. Cement (binding agent)
2. Aggregates (sand, gravel, crushed stone)
3. Water
4. Admixtures (optional)

Concrete: A Major Contributor to Resource Consumption

• Historical Use: Concrete has been utilized since Roman times.
• Current Consumption:
  • Portland cement is the most consumed material globally.
  • Annual global per capita concrete consumption is four tonnes, vastly exceeding food grain consumption.

Aggregate Consumption and Its Impact

• Material Statistics:
  • 105 Gt of materials consumed globally, with construction accounting for 62 Gt (~60%).
  • Global annual consumption of aggregates is around 40 Gt, expected to rise to 60 Gt by 2030.
• Environmental Concerns:
  • River sand mining banned in several regions due to ecological damage.
  • Excessive mining leads to habitat destruction for animal and microbial species.

Alternatives to Traditional Aggregates

• Circularity: Recycling non-organic solid wastes from demolished structures and industrial byproducts.
• Current Limitations: Less than 15% of solid waste generated is suitable as aggregates; India generates less than 0.20 Gt of useful solid waste annually against a requirement of over 4 Gt.

Future Challenges and Considerations

• Imminent Aggregate Crisis:
  • Shortages in aggregates for concrete structures anticipated in the near future.
  • Potential for rationing aggregates, similar to historical cement rationing in India.
• Shift in Construction Practices:
  • Possibility of a move towards steel structures due to aggregate unavailability.

Sustainable Alternatives: Biomass Products

• Biomass Potential:
  • Ample arable land available to grow biomass without impacting food security.
  • Non-woody biomass can be used for construction products, minimizing deforestation.
• Carbon Neutral Goals:
  • Substituting 50% of construction materials with biomass can lead to a carbon-neutral construction sector.

Conclusion

• Need for Sustainable Materials:
  • Achieving carbon neutrality requires reliance on renewable and sustainable materials.
  • A shift towards biomass-derived construction products is essential for a sustainable future.