Carbon Critical Design: Comparison of RE wall and RC viaduct on the Benz Circle Flyover, Andhra Pradesh

Adrian Anderson, General Manager Nehemiah Reinforced Soils (India) Pvt Ltd.

• Introduction• The design decision• The calculation• The results• Conclusion

Introduction

The design decision

The design decision

The calculation

Reinforced Concrete Viaduct (RC) Flyover

Reinforced Soil (RS) Wall Flyover

Tonnes of Material T CO2e/T Tonnes of material T CO2e/T

M20 Mass Concrete

24 T (Footings) 0.113 73T (Footings and anchor blocks)

0.113

M35 Reinforced Concrete

1014 T (Pre stressed beams 1.25% reinforcement by volume)

0.223 82 T (Facia panels - 0.48% reinforcement by volume)

0.121

M40 Reinforced concrete

643 (pre- stressed beams and crash barrier)

0.308 24 (crash barrier) 0.308

Compacted Aggregate

381 T 0.005 15,675 T 0.005

Steel (excluding concrete reinforcement)

48 T (Post Tensioned Cables)

2.830 14 T (soil reinforcing bars within backfill)

2.68

The Results

RS=0.36xRC

Conclusions

Move from Cost Critical to Carbon Critical Design

Informed Design

decisions

Simple calculation to make

Some local adaption required

Thank you

Adrian Anderson, General Manager Nehemiah Reinforced Soils (India) Pvt Ltd.