Specialized slipform paver constructs 75,000 m² of operational facilities by concrete paving
Wirtgen Group
A challenging concrete paving project was successfully completed in Iceland. The project involved the extension of the apron and a hazardous cargo pad at the military air base on the international airport at the port of Keflavik, about 50 km from Iceland’s capital, Reykjavik. The project was commissioned by the US Government. Wirtgen used the SP 62i slipform paver to pave a total of 35,000 m³ of single-layer concrete paving with a width of 7.62 m (25 ft) and a thickness of between 41 cm (16 in) and 45 cm (18 in). On average, 900 m³ of concrete were paved every day.
Due to the climatic conditions on the Reykjanesskagi peninsula in the south west of Iceland, the time window for the project was set for the beginning of July to the end of September, 2021. To squeeze the work into this timeframe, the decision was made to do without prior placement of fixed formwork for the individual strips. Precise edges were required for optimal surface drainage with a small cross-slope of 1%. The area was paved in 31 separate strips that were connected to one another by tie bars inserted along the sides to ensure the correct height of the individual sections. The outer edges of the strips posed a particular challenge for paving with the slipform method. They had to be precisely perpendicular from end to end and faultlessly paved with absolutely no fall. Only this can ensure that rainwater drains away as it should during future operations, and that no water collects in the expansion joints.
The required concrete properties in the case of the extension work at Keflavik Air Base included a concrete with the compressive strength class C35/45. In order to achieve the desired compressive strength of 45 N/mm² (cubic concrete specimen), the ideal formula for the concrete mix was determined with the assistance of Wirtgen application engineers and optimized for paving with the slipform paver. In situ paving of the first pilot strips was able to begin immediately without trial areas.
At Keflavik Air Base, the specified maximum permissible unevenness was 4 mm on 4 m. In reality, the evenness measured according to TP Eben 2007 showed that deviations were significantly lower and that the evenness achieved was far better than the target value.
On this project, we once again enjoyed the excellent experience of working together with the team from Wirtgen. The team provided excellent advice and valuable support in both the planning phase and as on-site consultants. Not least thanks to this, we were able to complete the project on time with as good as no problems at all on the construction site.
Hendrik Wendt, Site Manager & Concrete Technologist, HIB Infra GmbH & Co. KG
Facts and Figures of the Extension Project at Keflavik Air Base
Project Dimensions
Parking apron length: 280 m
Parking apron width: 235 m
Hazardous cargo pad length: 120 m
Hazardous cargo pad width: 76 m
Paving Data
Specified cross-slope: ≤ 1%
Paving width: 7.62 m (25 ft)
Paving thickness: 41 cm (16 in) – 45 cm (18 in)
Daily paving performance: 900 m³
Overall paved surface area: ∼ 75,000 m²
General
Construction contractor: HIB Iceland Ehf
Project timeframe: 07–09/2021
Wirtgen machines deployed: SP 62i
For more details, please see the project page.
Images provided by Wirtgen group press release.