Construction World September 2016

PROJECT PROFILE

planning with the help of structural engi- neer EKCON and principal agent, AECOM. Danie Jurgens, engineer for Murray & Roberts Western Cape, says an intricate back-propping system had to be designed and planned from the fifth level all the way down to the basements to support the transfer slab. The smallest pour was 320 m 3 and the largest 400 m 3 . Jurgens says that in line with the larger Murray Roberts Group’s STOP.THINK. ACT 24/7 campaign no one was allowed access in and around the site while the

concrete pours were under way.

The slab was undertaken in six individual pours and the concrete pumped 42 m from Bree and Buitengracht Streets in the early hours of the morning to avoid peak hour traffic in the CBD. About 2 000 m 3 of concrete was cast, commencing on 3 February and ending on 8 March 2016. Complicating the process was the intricate drainage system that had to be cast inside the slab, as well as its extensive reinforcing steel design. To accommodate this, two 550 mm thick

RIGHT: The scaffolding for the external works had to be carefully designed to accommodate the different trades involved in the façade that comprises different materials of different shapes and sizes. BELOW: The tower cranes had to be positioned carefully on the very congested site.

concrete layers were poured on top of each other with a five day curing period required between layers. The surface of the first cast was primed for the next pour by receiving a thin layer of concrete with a retarding agent and then sprayed with a jet of water. External façade Morilly says the external façade of the building is also a complex undertaking. It comprises different materials with a variety of shapes and sizes. These include bricks, windows and imported marble tiles, while close consideration also had to be given to the design of the scaffolding to accommo- date the various tradesmen right from the outset to avoid cost overruns. A very interesting aspect of the build is the merger of the new structure with the old Tothills Building. “This heritage building is being incor- porated into the front of house of the new structure and we have been tasked with restoring it to its original state, overhauling the roof, ceilings, walls and floors. We are working closely with the structural engineers and have already undertaken extensive tests to validate the structural integrity of the building,” Morilly says. Work on the project commenced in the rainy seasons in the Western Cape and Murray & Roberts Western Cape and one year into construction the company is on track for the contract completion date. It becomes very apparent that this will be yet another successful project completed by Murray & Roberts Western Cape in the leading tourist destination in the country.

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CONSTRUCTION WORLD SEPTEMBER 2016