With infrastructure currently one of the largest sectors in the region, Construction Week investigates how formwork firms are tackling the work available and adapting their products to suit contractor needs.

Take a journey through most of the Middle East's major cities today and the vast scale of the infrastructure work underway quickly becomes clear. Numerous roads, bridges, railways and tunnels are under construction and even more projects are planned, as the region's governments seek to create infrastructure systems that will meet the intense growth rates in their countries.

This is creating opportunities for all firms involved in civil works, with formwork at the heart of the initial project build phases and one of the most visible aspects of many of the projects to date.

"The proportion of civil engineering in the construction business is set to increase over the coming years," predicts Doka Gulf technical manager Bernhard Lindner. In addition to the need for infrastructure to meet the future growth within the region, the sector's dominance is expected to rise, as the economic downturn continues to impact on other building projects.

Its importance to the formwork industry is already being noted: "Certainly in Dubai at present the civil infrastructure sector is attracting the interest of Aluma and other formwork suppliers due to the current downturn in the commercial sector," confirms Daniel Taylor, area manager (Abu Dhabi), Aluma Systems Middle East. "As often happens during times of economic downturn, the Government stimulus packages pump investment into civil projects, meaning that the ratio of civil:commercial projects is increased," notes Taylor.

Issues to consider

With infrastructure projects generally of a much larger scale and vastly differing proportions to most building projects, any formwork used should be carefully selected and designed to meet the required demands. There are several issues that should be accounted for with such projects.

"From a design perspective, one of the main challenges is to create a true model of the bridge geometry and ensure that the design solution selected works for all cases," stresses RMD Kwikform regional chief engineer Moira Cameron. One way to reduce this problem is to use specially developed software programmes to ensure accurate designs.

"Traditionally this would have been done by cutting numerous sections through the bridge," explains Cameron, "RMD Kwikform has developed a programme in-house that enables us to accurately model both the ground and bridge geometry in 3D and to place the falsework legs automatically in 3D, which cuts the drawing time."

The sheer quantities of formwork required and their potential strength are other major considerations on infrastructure projects. "The amount of material will be high, so there has to be enough stock," says Peri product manager Shalin Adiparambil.

"The biggest issue is the large scale of the scope of work," agrees Taylor. "Generally the bridge/intersection works ongoing in the UAE at present require very large volumes of shoring to be supplied on a rental basis; the infrastructure market is also extremely competitive, meaning that the formwork supplier not only has to have the sufficient rental availability, but also has to provide the equipment at a very competitive rate," adds Taylor.

One benefit of this to formwork suppliers is that the long-term nature of infrastructure projects means if a firm secures a large contract it is guaranteed the long-term use of a large percentage of its rental fleet.

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Although ensuring safety on projects in general is a high priority, on infrastructure jobs it becomes particularly important and there can be additional requirements from the authorities. "Some companies have to prove to the RTA, in tests, that the formwork that they are going to use can carry the load that it says it can," reports Adiparambil.

"For example, a load test for the RTA was done in August 2008 with [Peri's] PD8-System for the interchange near the airport tunnel in Dubai, which was contracted by Yuksel," reports Adiparambil. Without passing such tests, the formwork would not be permitted for use on the projects.

"In infrastructure projects where high concrete pressures are involved, one cannot risk the safety issues, the time needed for reconstructing a damaged part and the additional cost, by using a cheap quality project instead of a reliable product," stresses VSL sales manager (Bar Systems) Shemi PS.

A further safety issue on infrastructure projects is their location: these are generally close to, immediately over, or alongside live traffic routes. Ensuring the safety of the public and construction staff, plus uninterrupted traffic flow on the existing routes, are essential components of the projects. "In case of interchanges or road bridges/tunnels, the traffic has to be adjusted, which in some areas is quite difficult," stresses Adiparambil.

"Building new bridges or flyovers accounts for similar problems, as when you are building a skyscraper, inside a congested city; the main problem is how to conduct the job, without interrupting daily life," adds Lindner.

All of the major formwork suppliers offer products that can adapt to such situations. Doka's Ready-to-Use Services for bridge formwork can provide a suitable solution: pre-assembled formwork panels are delivered to site to suit the project design, thus reducing the onsite assembly work. "On bridge projects the requirement is always to make a large volume of material available in a very short time," stresses Lindner, "therefore the clients have to rely on formwork suppliers with a perfect logistic department and commercial abilities."

"To cope with the need for traffic openings RMD offers its Megashor system to support simply supported steel beams over the live traffic lanes," reports Cameron. "The product is modular and can be assembled to suit any propping height required," she explains.

Formwork features

So with larger structures to consider, how does formwork for civil infrastructure works differ from that used in smaller scale projects such as buildings?

"As far as formwork material is concerned, there is not a big difference between building and infrastructure projects; sure the scale becomes bigger, but the idea of a formwork system incorporates the method of reusing standard items in as many different projects as possible," stresses Lindner.

By maintaining the use of standard products, installers do not require additional training in the use of the formwork and those who have worked on buildings can easily be transferred to infrastructure projects. This can provide contractors potential savings on time and money for training and during onsite installation periods.

Firms such as Peri offer product ranges that can be used across infrastructure and building projects. "The product range [needed for infrastructure projects] is different in some cases, in others it's not," states Adiparambil. "For example, Peri's PD8, ACS, SKS and GT24 girders are universal products that can be used in both project types, but Vario kit, GKB platforms etc are specialised products for infrastructure projects only," explains Adiparambil.

The differences in product are generally down to size and potential capacity. "We generally use our heavy-duty system scaffold, 80kN Rapidshor, instead of our medium-duty, 55kN capacity Kwikstage system," explains Cameron. "In heavy construction and civil infrastructure projects, the need for large diameters such as 20 and 26.5mm arise compared to the building projects where 16mm tie rods are the commonly used ones," adds Shemi.

Available products

With the focus on the infrastructure sector increasing, the formwork manufacturers are continuing to develop their products to meet the market demands.

Aluma's primary product for infrastructure applications is the Aluma Frame Shoring System. "This fully aluminium, versatile shoring tower makes up the bulk of the Aluma Systems rental fleet in the UAE," reports Taylor. "It is lightweight; fast and easy to install; versatile to any shoring application - commercial and civil; conforms to the highest safety standards; and has a very high load capacity (100Kn per leg) at optimal extension," stresses Taylor.

All of the systems used by RMD Kwikform for infrastructure projects are included in the firm's standard equipment ranges. For infrastructure falsework, the firm generally uses its 80kN Rapidshor System. "This system gives 80kN capacity with th‑e ledgers spaced at 1.5m, which can dramatically reduce the amount of ledgers and bracing required for more traditional systems," explains Cameron. "In addition, where heavy-duty propping systems are required, RMD offers our 1000kN capacity Megashor System," adds Cameron.

Doka offers a wide range of components and products to suit projects that involve bridges of almost any design. Again, standard products can be utilised. "The specialist formwork engineers use standard components, as extensively as possible, in order to ensure that even complex builds are completed cost-effectively," stresses Lindner. "The proportion of rentable system components can be as high as 90%, slashing investment costs for the construction companies and making formwork solutions economical even when use cycles are short," Lindner adds.

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Doka's Framax Xlife framed formwork or Top 50 beam formwork meets the needs of foundations and abutments. "If crane availability is a problem, the Frami Xlife framed formwork can be used because it is easily moved by hand," explains Lindner.

For bridge piers, pier heads and pylons Doka offers a wide range of climbing formwork systems including the SKE 50 and SKE 100 hydraulic climbers. For large loads, high floor-slabs, tunnels or bridges, the Doka load-bearing systems combine safety with flexibility. "Doka's Staxo 100 load-bearing system is extremely efficient and provides optimum adaptability to different layouts, floor shapes and large shoring heights," says Lindner.

In addition, Doka offers formwork solutions for bridge superstructures and has developed its own fully rentable cantilever forming traveller that comes complete with the integrated formwork for free cantilever bridging projects.

The modular system is designed to meet the specific needs of bridge-building, including aspects such as optimum formwork interfacing, rentability, ergonomics and safety. The firm can also provide products for tunnelling infrastructure projects, planning and providing modular and rentable solutions for cut-and-cover, excavation by mining, sheet-pile cut-and-cover tunnelling and galleries.

Peri has different product ranges for substructures and superstructures, plus special construction procedures such as the launching method. Several of the firm's standard products can be used for infrastructure projects, including PD8, multiprops, stacking towers, ACS, SKS, HD200 props, Variokit, tunnel forms, GT 24 girders and SB brace frames.

Peri's Variokit incorporates three standard components that can be applied to a wide range of applications: a steel waler universal SRU, climbing rail RCS and heavy-duty spindle SLS. Benefits of the systems include the need for few anchors in wall areas; optional hydraulic support for shuttering, striking, lifting and lowering; self-propelling or mobile solutions for moving complete units; and the ability to create different cross-sections by making simple modifications.

All components can be optimally adapted: the HD 200 heavy-duty prop allows continuous height adjustment and grid-free longitudinal arrangement; the RCS slab beam can be flexibly adapted; the Variokit diagonal strut is continuously usable from 4-9m.

In 2010 Peri is planning to release enhanced versions of several products. The Peri VT 20K is a 20cm-high solid web girder with improved protection at the girder ends. Robust steel caps have been added to the ends of the girder and concave web ends to prevent damage in demanding and tough conditions on the construction site, considerably increasing the service life of the girder. Here, the natural elasticity of the wood is also used to absorb the impact energy. In addition, the highly compressed solid web has a high proportion of synthetic resin that ensures high dimensional stability.

Project Details

There have been several high profile infrastructure projects undertaken in the region over the past few years, with many more underway or still to commence.

The Jumeirah Palm Island Tunnel project involved the construction of a 1.4km tunnel to join the main island with the outer crescent. This included 600m of underwater tunnel at depths of up to 25m. Forming, reinforcement work and concreting were carried out using the separate casting method.

In 25 m long concreting steps and four cycle sequences, the tunnel bottom plate, two wall sections respectively and then the slab could be concreted consecutively. Peri system components from the Vario girder wall formwork system provided the solution throughout. The load-bearing GT 24 formwork girders and SRZ steel walers were also used very flexibly as slab formwork. The concrete loads during construction of the tunnel slab were safely transferred into the bottom plate via PD 8 shoring towers.

Most recently, in early February Aluma won the contract for the Al Hodariyat Bridge Project in Abu Dhabi. The firm's Aluma Frame, Aluma Table and Aluma Wall-Form system will all be used on the VSL/AST joint venture project, with work on site due to begin in the immediate future.

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