Self-climbing crane independent systems are shaping falsework and formwork
By Steve Skinner14 April 2009
Crane independent self-climbing systems and improved safety structures are shaping the falsework and formwork sector. Steve Skinner reports on the new generation of formwork systems.
Through the adoption of self-climbing, self-lifting and enclosed systems, the falsework and formwork industry has taken big strides forwards in terms of productivity and worker safety. Independence from cranes has transformed site logistics, while integrated barrier systems have made working at height a far less hazardous occupation.
"Doka's table lifting system (TLS) has given us big gains in efficiency in comparison to using cranes," said Hirofumi Watanabe, project manager on the 100 m tall Mapletree Anson office building in Singapore. "This has accelerated our forming operations and meant that our tableforms are in use much more of the time because of shortened repositioning times," confirmed Mr Watanabe.
In Malaysia, Sunway Construction selected Doka formwork for its construction of two 40-storey office buildings in Putrajaya, and through the use of Doka Xclimb 60, neither high rise will require any crane time for formwork operations.
A total of 52 Xclimb 60 automatic climbers, with four separate platform levels and 2000 m2 of customised timber-beam formwork are being used to construct the cores. "We only have one crane on the two sites which is insufficient should we have needed to crane lift the formwork," said Richard Wong, managing director of Sunway Construction.
"As such, the crews are jumping the Xclimb 60 hydraulically on both buildings. For the floor-slab formwork we also have a Doka TLS in place so that we can lift the large area Dokamatic tables between floors without crane support.
"We are very happy with our decision to invest in Doka systems and seeing how it works, I am convinced that it's the right system," said Mr Wong.
On the matter of self-climbing solutions, Jürgen Schlenker, managing director of Hünnebeck Group told iC, "Self-climbing is ideal for confined spaces such as city centres where you cannot store anything. You don't need cranes and our Hünnebeck system carries not just itself, but also tools, equipment and people."
Tabla Construction Systems recently launched its Tabla Lifter, a self-climbing hydraulic scissor materials handler designed to lift its props and panels to the next working deck. "Because the modular Tabla shoring system is so fast to erect and strip it was necessary to develop a crane-free lifting device to maintain productivity," said Paul Gillespie, CEO.
The Tabla Lifter is constructed from three basic components; the platform at the top holds the material, the chassis at the bottom contains the hydraulics, operator controls and wheels (for mobility) and the scissor lifting mechanism links the two. With a capacity of 900 kg, the lifter is capable of carrying six panels or 25 props and can lift to a height of 14.6 m.
Extendable arms in both the platform and chassis mean the lifter can climb up through or outside a building, thus eliminating the need for crane assistance.
"The Tabla lifter is a purpose-built vertical-transportation vehicle that's safe, fast and efficient," Mr Gillespie told iC. "With the ability to erect our panels at 28 m2 per man hour and strip them at 56 m2 per man hour, it was imperative that we facilitated equally fast transportation between floors."
Meva offers its Meva Automatic Climbing system (MAC) that uses hydraulic rams to lift the entire working platform. "Apart from assembly, MAC is completely crane independent," said Jens Lützow-Rodenwoldt, Meva marketing manager. "A significant advantage of MAC is that work-flow is never hindered by high winds or adverse weather at height."
In Kuwait city on the Persian Gulf, Peri was selected to provide a self-climbing formwork solution for the Skidmore, Owings and Merrill designed 412 m tall Al Hamra Tower.
Due for completion in 2010, the ground plan of the tower resembles a round-cornered square with 60 m long edges. The central core is wrapped in a counter-clockwise spiral façade turning through 130 degrees and on the south side a quarter of the offset floor area is open.
"Construction of this distinctive structure has placed extremely high demands on both the formwork technology and the Ahmadiah construction team," said a Peri spokesperson.
"We have combined Peri automatic climbing systems (ACS) with the contractor's Trio panel formwork as well as Skydeck slab formwork and our SKS and Vario climbing formwork to provide a customised solution," continued the spokesperson.
"The formwork planners developed an integrated and uniform formwork concept for all 77 floors, which enabled us to keep adjustments to a minimum, and as such we've been able to complete each floor in an eight day cycle."
As well as freeing crane time and aiding formwork productivity, an important factor in the development of self-climbing and self-lifting systems has been worker safety.
"The attitude to worker safety has changed drastically and big advances are being made in this area," said Mr Rodenwoldt. "The formwork industry has done what it can, but the rest is now down to site management, which still has some way to go. We can design a system, but for it to improve worker safety it has to be fitted and used properly."
A point not lost on Combisafe's business development director Barney Green. "The biggest safety issue is getting all contractors to give their commitment to safety," Mr Green told iC. "If safety systems were integrated throughout every construction project, the benefits would be significant.
Combisafe was selected by the world's largest contractor, Vinci, to provide the safety systems for the construction of the company's new regional headquarters in Lyon, France.
The six floor building was constructed using a combination of pre-cast and in-situ concrete and in both cases, sockets were cast-in-place at pre-determined locations to support Combisafe's edge protection posts. Clamps and drill fixings were also adopted for reactive positioning.
"I wanted to upgrade the classic guardrails while keeping an impeccable level of safety," said Julien Garrel Luya, health and safety coordinator at the site. "Through working with Combisafe we were soon made aware of the importance of preliminary planning to integrate safety during all phases of construction," said Mr Luya.
"Both site management and site operatives that used the Combisafe products experienced the advantages of the system-based solution," said Samuel Lozinguez, the general foreman. "Having experienced this system it will be difficult to go back to old methods."
Safety is also at the core of Doka's formwork solutions. Stefan Pruckmayr told iC, "We are convinced that it is essential to focus on the issue of workplace safety during forming operations. Study after study has shown that safe construction sites are also cost-efficient ones."
Doka's Xclimb 60 forming system - that can be jumped either by crane or hydraulic self-climbing brackets - completely encloses four consecutive floor-slab levels with solid trapezoidal sheeting so that slab forming operations can be conducted in safe conditions, while the company's Ladder XS features an integral ladder cage.
"Doka has set itself the goal of extending its lead in workplace safety still further," said Mr Pruckmayr. "Far from paying mere lip service, at Doka this is one of the core specifications of our entire product development effort."
"Safety, ergonomics, accessories and new materials are key drivers in the sector," said Hünnebeck's Mr Schlenker. "Detail and solutions are what differentiate the big players. From equipment providers we became more service providers and now that's developed into being solution providers.
"We have to integrate our customer into a solution so that he believes in what he gets," Mr Schlenker told iC. "We send supervisors to help customers understand the formwork and we have technicians that are always in touch with the site to enable us to react quickly to the challenges of the project. Customer service is a crucial aspect of our business."
Meva's Mr Lützow-Rodenwoldt shares the sentiment, "The requirement is for us to become a solution provider rather than a product and technology supplier. We now have to go to far greater lengths in planning and conceiving a job site than we did ten years ago. The nuts and bolts of our individual systems and processes are what differentiate the main suppliers."
Greg Peacock, vice president of BEP Forming Systems of Kansas City, US told iC at the World of Concrete show, "The US market is now being led by service and infrastructure projects rather than housing. As such, our Big Wall panel with Power-tie (a system that eliminates the need for interior spacers) offers real time savings for these infrastructure type projects.
"Although we developed the Big Wall ten years ago, we are constantly upgrading the system and we're now offering a range of facings including plastic coated ply or all polypropylene as well as the more traditional Alum-a-ply (aluminium facing)."
The Big Wall panels are up to 3 m tall and 6.4 m long and use a 6 to 12 hole pattern, meaning the form can be jumped in increments of as little as 305 mm. "This system can handle up to 0.7 bar of concrete pressures, so we are now developing Alu-form that can withstand up to 1.4 bar for the new self consolidating concrete mixes," said Mr Peacock.
"Quality is everything," Hünnebeck's Mr Schlenker told iC. "There are more and more copies of our products in places such as Eastern Europe, India and China and we, the big three (Hünnebeck, Peri and Doka), therefore have to ensure that our intellectual property rights (IPR) are protected correctly.
"We have to show contractors that it makes business sense to go with the ‘original providers' and our support and service rather than copy systems. In this respect, service is a crucial aspect of our business."