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ULTRABRIDGES
Production Process
The production process of one standard Ultrabridge takes two to three months. Installation of the bridge to its final position does not take longer than one day. The following figures describe the production and installation process of the first Ultrabridge built by FDN in Rotterdam, in 2012.
Mold for deck elementsStandard wooden or steel molds are used both for the railing and deck elements. Deck slab is reinforced by pre-welded nets with special openings for connection between the slab and side beams. | Mold for railing elementsThe whole railing element is cast as one peace. The gaps determining bionic shape of the handrails are filled with removable polystyrene blocks. | Pre-stressing in the bottom beamThe tendons together with specially bent bars are positioned into the bottom beam of the railing elements. |
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Pouring of the concreteThe concrete with low w/c ratio behaves like a dense thixotropic material, especially at temperatures above 27°C. However, by the application of high-frequency vibrators (flex-shaft vibrators in this case), thixotropy changes more into more fluid behaviour, which is more suitable for compacting. | Curing of the concreteThe concrete must be properly cured in relatively short time by a oily-based milk compound. If the material is exposed to high temperatures and low humidity, the top layer of the freshly poured concrete tends to crack. | De-casting of the slabDe-casting process must be carefully executed with proper tools. |
Railing elementAll de-cast elements are stored and prepared for installation and pre-stressing. | Pre-stressingBridge elements are pre-stressed towards each other. The main pre-stressing tendons runs along the whole bridge in the bottom beams of the railing elements. | Assembly of the deckAfter railing elements are pre-stressed and grout in ducts is hardened, the deck elements are fixed onto the railing elements. |
Filling the gainsThe gains, through which the deck elements are connected onto the handrails, are filled with the UHPFRC concrete. | PolishingThe whole bridge can be alternatively polished and waxed. Important is to remove all steel fibers sticking out of the concrete. | TestingThe whole bridge can be tested for Uniformly Distributed Load 5.0kN/m2 and horizontal load 3kN/m acting on the handrails. |
LiftingThe bridge is relatively light if compared with other concrete bridges. Hence transportation costs are reduced. | TransportThe whole bridge can be delivered to its final position within one day. | Installation of additional partsNext to the main body of the bridge, additional elements can be installed for aesthetic point of view. |
The final resultThe installation of the whole bridge takes one day. Production of this bridge would take 2-3 months. |
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