Use of chalk on the A160 Port of Immingham Improvement scheme

The A160 Port of Immingham Scheme involved the upgrade of the strategic link road A160 to dual carriageway in the Northeast of England, which is an area underlain by some of the hardest chalk found in the UK. The site is located in close vicinity to a major chalk quarry, with well-established capabilities in lime and chalk production and supply. Significant financial and environmental benefits for the scheme were identified in using this local source of chalk for use in the road and embankment construction. In this paper details are provided for (a) the intended use of the chalk as a road foundation capping, embankment starter layer and drainage blanket material; (b) the characterization of the engineering properties and parameters of the chalk, substantiated by historical data research, testing, compaction trials and general observation; (c) assessment of site construction, handling methods to ensure continued suitability of the chalk, consistency in placement and compaction, and performance throughout the construction phase; and (d) design requirements regarding its long term performance.