CORROSION MSC required berth repairs for its new docking site next to the new passenger terminal at the Port of Durban
Establishing a new docking site for MSC
Mediterranean Shipping Company, better known as MSC, required berth repairs for its new docking site next to the new passenger terminal at the Port of Durban. A multidisciplinary approach, employing purpose-designed products from Sika, provided an enduring solution.
S
tefanutti Stocks, as the main contractor, was awarded the project for both the berth repairs and the construction of the passenger terminal. The berth repairs entailed removing and replacing 42 bollards, as well as 21 fenders, together with the rehabilitation and strengthening of the concrete surrounding these installations. The entire rehabilitation programme took eight months to complete. The primary specialist was Engineering Projects and Naval Architecture, which designed and planned the project. Doing the specialist work were main contractor Stefanutti Stocks Coastal, together with two subcontractors – Structural Maintenance as well as Holmes Cutting and Coring. The project and quality managers were sourced from Turner and Townsend.
Process To start, Holmes cut out and removed the existing damaged bollards and their anchoring bolts. The team then cored 16 holes per bollard, at a racked angle to allow for the new reinforcing – each 80 mm in diameter and 8 m deep. The existing
Various Sika products were employed to ensure structural integrity
tyre fenders were removed and the quay wall stabilised. On completion, each of the 16 core holes were filled with a high-strength cementitious grout, SikaGrout-212. Sika UCS-01 ZA, an underwater admixture that forms a jellylike substance when used with a cementitious product, was used in conjunction with SikaGrout-212 to prevent small sand particles washing away. Sika UCS-01 ZA was also used by Structural Maintenance for the grouting installation on the new bollards and core holes. Once the installation of the bollards was complete, rehabilitation between the new and existing concrete was required. This was carried out using SikaGrout-212 and a joint sealant system comprising Sika Primer-3N and Sikaflex Pro-3i. This joint sealant system filled in and sealed all cavities, voids, gaps, and recesses. The use of these products created a neat, uniform look around each bollard and allowed for movement between the old and new substrates. Sika’s joint sealant system was also used around the outer edges of the repaired areas.
Deadman anchor block The so-called ‘deadman anchor block’ needed to be rebuilt 20 m inside of the main quay wall, spanning the full 400 m length of
the berth. It’s a massive concrete anchor that supports the bollards and helps resist the forces exerted on them by the huge, docked ships. Construction of the deadman anchors required an initial base unit of cast concrete. Sika Rugasol-2 liquid was used as a surface retarder to prevent the concrete from setting, and to provide a key before the second layer was cast upon it. To ensure the berth wall was structurally sound, three new anchoring rods were installed between the deadman anchors and the bollards. Sika Antisol E was applied to cure the concrete and prevent shrinkage cracking from rapid water loss.
Challenges Along with the ever-changing tides, and seawater seeping into the core holes, the contractors also had to deal with the narrow tolerances around the large Y40 reinforcing bars. The areas surrounding the construction site were also situated on reclaimed land. This presented problems through the presence of old oil, fuel pipes, old railway lines, water lines and the main electrical feed to the entire port. Working around these historical objects made every task a little more difficult. Despite the unique conditions, and unexpected challenges of this project, Sika’s specialised products ensured success.
IMIESA July 2021
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