Innovative Method for Sustainable Road Construction, Norouzi, Pokharel, Breault M, Breault D (2017)

Analysis of Neoloy-reinforced pavement construction shows that Neoloy Geocells reduce CO2 emissions by 20%, construction costs by 10%

Summary

In this paper, Norouzi and Pokharel quantify the impact of Neoloy Geocells on sustainability. They compared the economic, environmental and social impact of constructing a Neoloy-reinforced road in Alberta, Canada, with an equivalent unreinforced road. Their calculations concluded that using Neoloy Geocells on such a stretch of pavement reduces construction costs by 10% while at the same time saving 20% on CO2 emissions. In addition, they stressed that using Neoloy Geocells saves at least 25% saving on layer thickness and aggregate infill.

Challenge – Truly sustainable pavement construction

There is a growing and significant trend to achieve sustainable development. The construction industry accounts for 40 per cent of stones, sand and gravel, plus 40 per cent of the total energy produced in the United States annually, of which road construction is a major contributor. There is a pressing need to find new sustainable road construction methods, which make a significant positive impact on the environment, economy and society.

Validation – Comparing road construction in Alberta, Canada

Authorities in the village of Ryley, Alberta decided to use Neoloy Geocells in the reconstruction of the 1.8 km long, 50 Avenue. Norouzi and Pokharel calculated the monetary and environmental cost of the project. Using design parameters suggested by Alberta Transportation, they compared these results with the construction of an equivalent, typical rural road in Alberta, using conventional, unreinforced construction solutions.

In particular, they compared the costs of excavation, granular aggregate and asphalt used in construction. They also compared the per tonne emissions of CO2 for each construction method.

Results – Cost-effective, environmentally friendly, sustainable solution

The reinforced road in Riley was comprised of 100 mm of Asphalt Concrete and 240 mm of GBC on a 30 MPa subgrade. The suggested design parameters of equivalent unreinforced pavements is comprised of 125 mm of Asphalt Concrete and 340 mm of GBC. Using Neoloy Geocells represents a 25% saving on layer thickness.

In addition, deploying Neoloy also utilizes significantly less materials during the processes of excavation and construction. In total, using Neoloy Geocells saved $135,000, equivalent to 10% of the entire construction costs. The authors recommended further studies, a ‘3D analysis’ on the potential savings during the entire pavement life-cycle, which they suggest would demonstrate an even lower total cost of construction.

Using the US-EI database, which calculates that during the production of 1 ton of crushed aggregate, 10 kg of CO2 is released into the atmosphere, the authors compared the CO2 emissions of Neoloy-reinforced and equivalent unreinforced pavement. They calculated that using Neoloy Geocells to reconstruct 50 Avenue in Riley, resulted in a reduction of 93,500 kg CO2 emissions. This is equivalent to a 20% reduction in emissions compared to a similar unreinforced pavement.

Benefits – Reduced costs, fewer emissions, positive societal impact

Norouzi and Pokharel concluded that “The results of this paper indicate that Neoloy Geocells can be one of the smart ways to invest in road construction and rehabilitation since they maximize the useful life of the road structure while reducing ownership cost and CO2 emissions.” In particular, it brings the following benefits:

  • 25% reduction in pavement thickness
  • 10% overall reduction in construction costs, enabling greater spend on alternative social amenities
  • 20% reduction in CO2 emissions
  • Positive economic, environmental and social impact, tangibly increasing sustainability

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