Two stationary concrete pumps and placing booms from Putzmeister are currently working on the Mediterranean coast of Egypt, helping build the £E3 billion ($519 million) San Stefano Grand Plaza in Alexandria. Putzmeister’s equipment has already placed over 200,000 cu m of concrete in the process.
Being built in an extremely attractive location directly on the sea front, the San Stefano Plaza, consists of a total of 10 towers of different heights. The complex comprises amongst other components a five-star hotel, 800 apartments, offices, cinema and theatre halls, a four-storey shopping centre, several restaurants with a sea view and three underground parking levels.
The $88 million project is being undertaken by a consortium of Murray and Roberts (South Africa), Al Habtoor (UAE) and SIAC (Egypt).
“After intensive consultation with Putzmeister project engineers and the local PM agent International Development Programmes (IDP), the plan for economic placement of the concrete in the numerous formwork sections of the ample area was defined,” says a spokesman. ‘With just two stationary MXR 32-T concrete placing booms, which were used alternately on five tubular columns distributed across the construction site, an extremely cost-effective and at the same time highly efficient solution had been developed.”
Putzmeister describes the procedure, in which a few concrete placing booms work alternately from several tubular columns as a “satellite system”. Due to the detachable ballast beam and the four arm sections, the MXR booms had significant advantages in construction site operation: for example, the gross weight of the boom could be split into two loads and thus also be offset by a relatively small construction crane. And, thanks to the four flexible boom arms, the working area of the stationary boom was always well matched to the structure. As a result, it was also possible to concrete formworks and reinforcements in awkward positions.
The concrete was delivered with two stationary Putzmeister concrete pumps of type BSA 1409 D, through several 30 to 50 m long, and up to 120-m-high anchored pipelines. With two shut-off valves, it was possible to interrupt the flow of concrete – for cleaning operations and for connection to a different boom line. In all, the consortium placed 1,000 m of delivery lines at San Stefano Plaza. The concreting operations generally took place during the night, primarily because of the cooler ambient temperatures, and also due to the lower volume of traffic.
The concrete which contained amongst other things – broken material with 19 and 12 mm granulation as well as solvent and other additives – strictly complied with the slump dimension of 22 cm, he says.
In each case, between 25 and 50 cu m/h were pumped by the BSA 1409 D. In total, the individual concrete volumes came to a total volume of approximately 201,000 cu m, he points out.
