タグ: Product

On the French island of La Réunion (located 700 km East off the coast of Madagascar), a joint venture composed of contractors VINCI Construction Grands Projets, Bouygues Travaux Publics, Dodin Campenon Bernard and Demathieu Bard, is currently building a new offshore elevated 2×2-lanes viaduct of 13 kilometers, which aims to replace the older unsafe road structure, located along the coast and frequently damaged by rockfall.

For this large project, VINCI is operating a large custom-made platform named “Zourite” to position, lift and sink heavy precast bridge piles – an engineering challenge considering the individual weight of the elements: up to 4,800 tons for the base of piles!

The JV members and Dextra worked together to design a lifting system based on M64 smooth bar systems in high performance grade 930/1080, with each system withstanding loads up to 200 tons.

each anchored to concrete thanks to 8 Dextra bar systems.

A total of 32 bar systems are anchored directly into the concrete base of each pile and post-tensioned using a hydraulic rotary jack before lifting.

Once the base reaches its final location, the top part of the anchorage is dismantled by divers so it can be reused for the installation of other piles.

The first piles have been installed at the end of August. A total a 48 piles will support the Route du Littoral viaduct, all lifted thanks to more than 1,500+ Dextra bars.

Doha Link is a 12.4km project connecting Kuwait City (from Shuwaikh Port) to Doha Area. It will ultimately solve traffic congestion and offer a direct itinerary between the two areas thanks to a 7.7km bridge built on shallow waters across the Kuwait Bay.

Two different Dextra solutions are currently used for the piling works on the Doha Link project:

>> Rolltec® couplers for large diameter rebars (32, 36 and 40mm) are used onshore and offshore for the connection of cages and piers. Two grades of rebar are used across the project: ASTM Grade 60 and Grade 80. Rolltec being compatible by design with the higher ASTM Grade 80, same couplers may be used on all applications, simplifying stock keeping. In addition, smaller diameters couplers for rebars 12mm and 16mm are being used in the superstructure and the footing of light poles.There are currently 4 actively running Rolltec threading equipment on site. Dextra team provides continuous support to the contractor GS Engineering & Construction to maintain rebar production at the productivity level and quality standards required.

>> Sonitec®. With large piles of 2.5m diameter and 60m depth in average, it was compulsory for GS E&C to conduct sonic logging tests to examine the integrity of concrete piles, requiring to install 8 tubes in each cage. Dextra Sonitec was the preferred choice of the contractor thanks to its light weight and unique Push-Fit® connection feature. Sonitec provides enough flexibility during the cage construction, lifting and assembly to remove needs for additional time-consuming welding operations.

Doha Link, which delivery is expected on time end of 2018, will also be linked through an interchange to Jaber Causeway, another bridge project located north of Kuwait City, on which Dextra is also supplying its solutions.

In July, the first Griptec connections were produced on the site of the 5th reactor of Fuqing nuclear power plant, located in the Chinese province of Fujian.

Dextra is thrilled to be part of the construction of the first reactor to be built after a 100% Chinese design. 400,000 Griptec connections will be used in the next 5 years, mainly in the aircraft protective shell.

Griptec is the preferred rebar splicing solution of the nuclear industry thanks to its unique performance and an automatic proofing process which tests 100% of the connections.

Griptec has been supplied to nuclear projects like Taishan EPR 2&3 in China and Flamanville EPR 3 in France.

More about Griptec in our product brochure:

Temporary ground anchors are used in numerous applications including slope stabilization and excavations. Contractors usually install steel ground anchors, and then remove them once they become obsolete: a double burden.

Dextra has developed a range of innovative post-tensioned anchors: ASTEC Active Anchor (AAA)

• Cuttable tendons made of GFRP material, corrosion resistant and possessing with tension performance to steel. More importantly in this case, it has the advantage of being easily crushed by tunnel or piles boring machines. Therefore, it doesn’t need to be removed from the ground.
• Conventional steel PT strands compatible with any standard tensioning device (hydraulic jack), connected to GFRP tendons thanks to a proprietary connector. Assembly, installation & tensioning remains the same as for steel ground anchors.

Since mid-2014, Dextra delivered thousands of ASTEC Active Anchors in the Middle-East, both using CFRP & GFRP material. Many of them have been used in projects related to Doha Metro in Qatar, combining up to 10 tendons for an ultimate capacity of 250 tons. The FRP anchors have been selected as they allow the tunnel boring machine to cut through without generating any issue of encroachment on neighboring plots.

Our production has achieved new record figures for 6 months in a row with an average production of more than one million couplers a month. This performance has been made possible thanks to recent improvements on production lines as well as full commitment of our production teams.

Also in Bangkok, HR and Quality department teamed up to organize the 3rd edition of Dextra Manufacturing annual “Quality & Safety Days”, a crucial part of a long-term strategy to boost Quality and Safety. This 2 day event is dedicated to the promotion of safety practices and quality awareness through numerous activities for factory operators and office staff.

With main Quality and Safety KPIs improving consecutively over the last 3 years despite a large increase of the production volume, efforts are paying off! Congratulations to the teams!

Dextra inaugurated a few weeks ago a new factory building in Bangkok, adjacent to its existing manufacturing facilities.
This new facility of 1,300 sqm of production and 335 sqm of offices houses Dextra research and development center, a certified testing laboratory as well as a machining and equipment assembly workshop. Thanks to this expansion, the manufacturing capacity for equipment parts, tools and accessories will be boosted four folds.

Dextra bars manufacturing yard has also expanded by 25% with more space allocated for the Tie Rods/Tension Bars and Waling Beams production.

The last step of the expansion plan will take place during the second half of 2014 and will lead to a larger area for the splice manufacturing to support Dextra business expansion.