Full Grouting, Westkapelle Coastal Revetments

Part of the coastal defences near the town of Westkapelle in Zeeland were identified as being under strength to deal with revised hydraulic loads from the North Sea. The existing revetment comprised of concrete blocks and grouted rock which required strengthening from the toe to the MHWS level. The works comprised of overlaying the area with a layer of fully grouted rock and a new partially grouted rock toe.

Main contractor for the works was Boskalis and the asphalt was produced by Hydraphalt vof (a joint venture company between Ooms and Hesselberg Hydro).

Details

• Over 3 km coastal defences upgraded
• 130,000 m2 revetment – 600mm thick fully grouted rock
• Rock toe partially grouted to increase strength and retain porosity
• Over 80,000 tonnes mastic grout produced & installed over two ‘summer’ seasons (2006-2007)
• New mixing unit developed for project capable of producing over 120 tonnes mastic grout per hour.