The new dairy ingredients processing plant for Olam Foods Ingredients (OFI) at Tokoroa in the Waikato region is a design and build project undertaken by Silvester Clark together with GEA and First Principles Constructor (FPC).

The project largely involves design of a 38m tall dryer tower (equivalent to a 12 storey building). The building mainly houses a massive drying chamber assembly, a main bag filter unit, and calandrias in the evaporator hall that extends all the way from the ground to the floor levels at 23m and 27m. The roof is built using steel plates, but all other floors consist of precast flat slab and in-situ reinforced concrete topping supported on a combination of steel and precast reinforced concrete beams. Precast concrete columns and wall panels support the building down to a shallow raft foundation.

The lateral load resisting system of this large box-type structure uses the reinforced concrete topping (only 4 floor diaphragms) to transfer loading out to the precast concrete wall panels. In addition to the atypical layout of each suspended floor, several large openings in the floor diaphragms required for the processing plant equipment, add significant complexity to the structural design.

Besides the main dryer tower with a number of steel access platforms, there are several ancillary structures that form part of this project which include a 2400 sqm dry-store, powder-bin packing building, amenities block, services building, silo pads, sprinkler valve house, tanker reception, transformer pads and pipe bridge.

Currently, the project is under construction with a programmed completion date of March 2023.