First flat slab technology project completed at Pender Gardens
The first project using BubbleDeck technology in Malta was successfully completed at the Pender Gardens complex in St Julian’s. This innovative system, which was launched in Malta two years ago, was used in three levels of underground parking, totalling some 3,500 square metres.
Pender Gardens CEO Peter Diacono said that from the onset he and his team were confident, especially after reviewing projects carried out internationally, that the BubbleDeck system would work locally and that he would definitely have no reservations to the use of the system on future phases of the project.
The BubbleDeck slab system is not dissimilar to other materials used in construction, like wood and steel and other pre-cast concrete elements (such as planki and predalle), as these pre-cast concrete slabs are delivered to the construction site already containing the required bubbles (hollow, plastic balls) and reinforcing steel.
This facilitates the efficient placement of these structural elements, consequently saving time, manpower and, of course, money. The fact that these structural elements are prepared in a manufacturing plant ensures better workmanship and minimises the required input from the workforce on site.
These time and logistical savings are only two of the benefits when using BubbleDeck technology. The inclusion of the bubbles within the core of the concrete slab allows for a lighter structure and therefore less construction material within an overall lighter structure.
The fact that the structure is lighter enables for larger spans, which in turn reduce the number of load-bearing elements (columns and foundations) required. Since BubbleDeck technology is a flat slab system, no beams are needed, thus increasing invaluable internal headroom.
Since the technology is very flexible, each construction site will have its own curtailed, structural layout. BubbleDeck Malta Ltd, together with BubbleDeck International, have studied the particular construction requirements of Malta to exploit the advantages this technology has to offer, resulting in the most efficient structural system in more ways than one – time, cost, weight, headroom.
At Pender Gardens alone, a BubbleDeck slab replaced a conventional, solid, reinforced, concrete, flat slab. The result included a 30 per cent reduction in the required steel reinforcement, together with a reduction of approximately 25 per cent in the required concrete.
The use of this technology around the world is greatly increasing. Two projects worth mentioning are the New Administrative Centre of the Federal District in Brasilia, Brazil, and the Piedmont Tower which, when completed, will be Italy’s tallest structure.
BubbleDeck slabs are being increasingly used to add additional floors to existing, older buildings. This is due to the lightweight nature of the technology, therefore reducing the new, imposed loads considerably on existing foundations and load-bearing elements.
BubbleDeck Malta Ltd is an associate of BDI, which is based in Denmark. Director and senior engineer Kim Breuning made two visits to Malta prior to the start of pre-cast predalle fabrication last April and before the first slab was cast a month later. BubbleDeck International are committed to ensuring that the technology is implemented correctly and most efficiently.
BubbleDeck Malta Ltd engineer Andrea Sammut was responsible for overseeing the process of manufacturing and casting the BubbleDeck slabs at Pender Gardens with General Precast Ltd, the contractor carrying out the civil works, who were also the first to appreciate the advantages the system offers.
BubbleDeck Malta Ltd, with the help of BDI’s support staff, also provided the construction and shop drawings, thus providing a complete service and ensuring a smooth, seamless construction process from the manufacturing plant to final concreting on site.
Adrian Falzon, structural engineer for the contractor responsible for the design and build of Block 16 at Pender Gardens, also had words of praise for the way BubbleDeck Malta handled the imple-mentation of this new construction system.
Source: Times of Malta