N22 Ballyvourney to Macroom
The Challenge: The project included for the construction of 22km of dual carriageway to exacting standards, this included four main junctions at Coolcour, Gurteenroe, Toonlain and Ballyvourney. From conception the scheme set out to bypass both the towns of Macroom and Ballyvourney through often very challenging terrain. In addition, the project interfaced with the existing N22 national primary route at several locations along the route which introduced challenges such as maintaining existing traffic flows.
Following the initial design which was carried out by Barry transportation and the main JV contractor, Roadstone was contracted to construct the pavement structure. This required both the Roadstone R&D team and Contracts division to carry out extensive mix design and trials to ensure compliance with the overall pavement design.
A brief outline of the design parameters is as follows.
- The Mainline incorporates a 40-year design life
- Pavement to flexible composite design
- Overall Pavement Thickness Of 340mm
In order to fulfill the needs of the client the following quantities were required.
- 150,000-ton Clause 804/808
- 175,000-ton CBGM
- 170,000-ton Blacktop Of which recycled materials were used.
- 30,000-ton is Stone Mastic Asphalt of varying PSV values depending on skid resistance requirements noted within the design documents.
Prior to the construction phase commencing significant capital expenditure was deemed necessary. Potential risks to pavement durability at the interface between carriageways and lanes was identified. If water ingress was not prevented this could affect the overall design life of the pavement structure.
Therefore following this initial assessment the following plant was procured and used.
- Vogele 1083–3i with extended screed purchased specifically for N22 Contract
- 3 no. Bomag 161AD with intelligent compaction technology
- Atlas Capco – Material Transfer Vehicle
- Several pieces of ancillary plant and equipment
Aside from structural integrity of the pavement, ride quality is always considered as an essential prerequisite to a successful road project. Stakeholders deem this of utmost importance as Its what the end user notices immediately. In order to achieve this objective the following measures were taken.
- Strict Adherence to TII And Site-Specific Specifications
- Purchase of Vogele 1083–3i with extended screed of 8.5m which ensured that each carriageway could be laid in one pass
By utilizing a material transfer vehicle, sonic sensor averaging beams, and the extended screed paver an exceptional pavement surface was achieved. Roadstone Contracts division was able to achieve the following results.
- Average of 1.1 on binder course
- Average of 0.79 on surface course
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N22 Ballyvourney to Macroom
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N22 Ballyvourney to Macroom
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N22 Ballyvourney to Macroom
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N22 Ballyvourney to Macroom
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N22 Ballyvourney to Macroom
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N22 Ballyvourney to Macroom
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N22 Ballyvourney to Macroom
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N22 Ballyvourney to Macroom
