Chief Executive's Upfront
Concrete Roads for Resilient Infrastructure

In the ever-evolving landscape of transportation needs, concrete roads have an established international pedigree, offering a compelling solution for roading authorities.

Rob Gaimster, Chief Executive

New Zealand, facing challenges like heavier traffic loads, the transition to net-zero carbon, and poor infrastructure investment, is now pursuing the benefits of concrete roads.

With a commitment to expedite the consents process, a fast-track mechanism for the construction of essential infrastructure is also being explored. Additionally, the creation of a 30-year infrastructure pipeline reinforces the government’s commitment to building resilient and sustainable infrastructure. All of which sets the scene for investment in the advantages of concrete roads.

The circular economy aspect adds another layer of sustainability to concrete roads. At the end of their service life, concrete roads can be recycled, aligning with New Zealand’s waste minimization objectives. The crushed concrete can be reused in various infrastructure projects, promoting a sustainable cycle.

Safety is paramount, and concrete roads offer texture for traction, skid resistance, and reduced noise, as well as a brighter surface for improved driver visibility, and enhanced ride comfort.

Concrete roads contribute to fuel savings due to their rigid structure, preventing rolling resistance. Research by the Massachusetts Institute of Technology (MIT) indicates potential fuel cost savings, potentially reducing total transport-related emissions by about 0.5 percent over 50 years in the USA.

The lower carbon footprint of concrete roads further strengthens their case. A study commissioned by the Cement Association of Canada reveals that the primary energy costs of concrete roads over their lifespan are around one-third that of asphalt roads. The difference in New Zealand will be less pronounced with a higher percentage of renewable electricity available. However, this is still an important consideration.

Strategies to lower the industry’s carbon footprint involve the use of waste materials as alternative fuels (both biomass waste and fossil-derived waste) in clinker production, as well as the increased use of mineral additions and Supplementary Cementitious Materials to replace clinker in cement. From 2030 to 2050, intensified efforts include the use of Carbon Capture, Utilisation, and Storage.

Accounting for concrete’s carbon uptake ability, a natural process by which the exposed surface of concrete absorbs CO₂, is another strategy. In fact, the UN has acknowledged this sequestration mechanism, a significant tick in the plus column for concrete considering the surface area of roads

Citing the United States, where concrete roads are prevalent, Ferrebee highlighted their versatility, durability, and cost-effectiveness. The longevity and effectiveness of continuously reinforced concrete pavements (CRCP), which do not require transverse contraction joints, also left an impression on Ferrebee during his stop-over in Australia.

Tauranga City Council faced challenges in the suburb of Tauriko, dealing with low subgrade strength and shallow services for two roundabouts linked by 300 metres of connecting road. Utilising Roller Compacted Concrete (RCC), Rolco NZ worked with concrete supplier Firth Industries, to provide a thin but strong pavement option with rapid construction times

The outlook is bright, with the economic efficiency, environmental responsibility, and climate benefits making concrete roads an entirely viable solution for New Zealand’s evolving transportation needs.