The construction of Newcastle Mall, in KwaZulu-Natal, has been completed, reports multidisciplinary construction and engineering group Aveng Grinaker-LTA. It was officially opened recently by President Jacob Zuma.
The new mall offers a gross lettable area of 37 000 m2, along with 2 222 parking bays. Aveng Grinaker-LTA’s R245-million construction contract was undertaken in 12 months, and MD Grahame McCaig explains that this challenging timeframe was achieved by incorporating the innovative ‘tilt-up’ construction technique into the project.
Tilt-up building involves concrete elements such as walls, floors, columns and structural supports being cast and cured on site, and then tilted up from a horizontal position using a crane, from where they are braced into posi- tion and later secured. At the Newcastle Mall, tilt-up was used for all perimeter and loading yard walls, McCaig states.
“The client selected tilt-up as it is much quicker than conventional building processes and the building was completely closed up in a relatively short period. Tilt-up construction consists of two stages – the casting of the panels on surface beds, or sacrificial beds, and lifting of the panels into position. It is a process that requires skill and precision, but since it eliminates many of the requirements of conventional brickwork, such as access scaffolding, tilt-up is worth the effort.”
Lower maintenance costs are a further bene- fit of tilt-up. “There is virtually no long-term maintenance needed of unpainted tilt-up walls, making this method far cheaper in the long run than conventional plastered walls that have to be painted and maintained on a regular basis over time. When lifted, the tilt-up panels are basically a finished product,” he notes.
Ensuring the supply of the required volumes of concrete needed to cast the tilt-up panels and meet the tight construction programme was one of Aveng Grinaker-LTA’s challenges on this contract. McCaig says that the contractor also overcame sequencing challenges. “The order of various elements had to be carefully planned to ensure the correct sequence of events, from surface-bed construction of the concrete panels to the time the panels need to be in bracing bays for support through to the construction of the roof structure.”
Space constraints were also a considera- tion. He explains: “The tilt-up panel stacks took up a fair amount of space on site and all other activities had to be planned around these areas.”
While tilt-up is a faster process than conventional construction techniques, it requires a testing degree of precision in terms of the placement of the panels. “Alignment of the tilt-up panels has to be 100% perfect in order to ensure the precise positioning of the external finishes such as ceiling shadowlines against the panels. At Newcastle Mall, tilt-up proved its value, with the end result being an attractive, upmarket shopping centre that’s set to be a boon for the local community,” McCaig notes.
A total of 9 510 m3 of concrete was used in this project, together with 423 t of reinforcing steel and 1.9-million bricks.