Ireland Climate action and sustainable development, Housing and planning, Transport and infrastructure

Sustainable solution for local and regional roads – Monaghan County Council


Source: Monaghan County Council

Since 2020 Monaghan County Council has piloted the Cold-Mix-Recycling of thousands of tonnes of previously discarded material turning it into a viable sustainable product that can be reused in roadmaking, thus achieving vast reductions in waste, contributing to the circular economy, and achieving carbon savings of over 50% when compared to conventional road construction methods, whilst, also improving the connectivity of our rural communities in a sustainable manner. Asphalt road millings are a by-product produced in the resurfacing of sub-standard roads. Small quantities have traditionally been re-used as low value granular fill, however, typically most of the milled material is disposed of as waste, or stockpiled. Monaghan County Council has been developing the Cold-Mix-Recycling initiative with the DOT, TII and various other industry leads, and in 2024 they secured regional project approval to share knowledge and expertise with neighbouring authorities to expand this initiative for both road and greenway construction.

The main objectives of the project were to:

  • Reduce waste and promote the circular economy.
  • Reduce the council’s carbon footprint and energy consumption.
  • Achieve better value for money in road resurfacing operations.
  • Connect the rural communities in a sustainable manner to enhance their quality of life.
  • To align with National & International standard to enhance the environment and to reduce our impact on the environment in a more sustainable and cost-effective way.

In August 2023 Monaghan County Council completed the latest phase of the project in Emyvale Co. Monaghan. The project construction phase consisted of:

Grading & Stockpile Control; The Recycled Asphalt pavement was suitably graded and sorted into 100% “RAP” Aggregate stockpiles ready for use.

Production: The material was processed using a specialised cold mix batching plant (Figure 1). The final cold-mix asphalt consists of 94.5% “RAP” Aggregate mix, including 1% cement, 4.5% C60B4 Bitumen Emulsion and 1% water for moisture content.

Figure 1 – Cold-mix Asphalt Batching Plant

Soure: Monaghan County Council

This type of cold-mix asphalt is an environmentally friendly road maintenance technique, as the RAP material being recycled does not need to be heated during the mixing process (Figure 2).

Figure 2 – Conventional Road Paving Techniques

Source: Monaghan County Council

Installation – Cold-mix asphalt is suitable for use in the base and binder course of the pavement and can be transported and installed using conventional paving techniques. When used in the binder course, the cold-mix asphalt is sealed with a double Surface Dressing Layer.

Monaghan County Council is proud to be Ireland’s leading local authority in this sustainable, environmentally friendly initiative using up to 100% reclaimed asphalt pavement or RAP.

Monaghan County Council would like to thank everyone at the Department of Transport, TII, Colas Ireland, PMS, ARUP, and TH Moore (Contracts) Ltd. for their cooperation and continued partnership in this project.

YouTube of Monaghan County Council’s Cold Mix Trial 2023


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