The Bezons Viaduct is part of the extension of Paris’ suburban train line E (Eole), a hybrid transit system connecting the capital to its suburbs. This viaduct features a 96-meter-long bowstring-arch bridge that links the new train line to the existing network, allowing it to pass over an active railway line below.

To ensure the stability of the 2,000-ton structure, a robust concrete tensioning system was required, and Dextra provided its Tiges de tension for the task.

Dextra’s Tension Rod System is a high-performance solution designed to provide structural stability in various construction applications, particularly in bridges and viaducts. It provides a reliable method for applying and maintaining tension across structural elements.

The success of the project, both in design and customer satisfaction, was driven by the strong collaboration between Dextra and its local partner, Freyssinet.

Image credit: https://www.lemoniteur.fr/article/bezons-le-bow-string-du-saut-de-mouton-d-eole-est-en-place.2044730#! ©CHRISTOPHE RECOURA/FOORESO

The Indonesian Ministry of Public Works (MoPW) commissioned the construction of the Mahakam IV project, a twin-bridge system crossing the Mahakam River in Samarinda, East Kalimantan. The project includes two separate bridges: a 1,388-meter-long cable-stayed bridge with a 220-meter span, 17-meter width, and 22-meter vertical clearance, and a 740-meter-long main bridge with a 14-meter width and 25-meter vertical clearance.

Dextra was involved early in the project, providing BIM tools to integrate the tension support system into the overall structural design.

In total, over 60 carbon steel tension rods of various lengths were delivered to the construction site. The system’s forks and turnbuckles allow for adjustable lengths to meet specific site requirements. Dextra’s tige de tension system efficiently absorbs the structure’s tension loads, with a range of strength grades and surface finishes available to meet both technical and aesthetic needs.

Le projet a été achevé et ouvert à la circulation en 2019.

The National Highway 44 (NH 44) is India’s longest highway, stretching 3,745 km from Srinagar to Kanyakumari. As urbanization accelerated, cities along the highway grew rapidly, leading to a significant expansion of neighborhoods adjacent to the road. This growth has caused congestion, as pedestrians and light vehicles along the highway often disrupt the flow of long-haul heavy vehicles, creating safety risks for both local traffic and pedestrians.

To address these challenges, the Highway Authority of India proposed road widening, along with the construction of flyovers over stretches running through densely populated towns. A 34-km elevated stretch of highway between Nagpur and Hyderabad is being developed to improve connectivity between the two cities.

The authorities opted for segmental construction technology for the elevated bridges, with each heavy segment being Préfabriqué in a controlled environment at quality-assured Préfabriqué yards. Given the substantial size of the Préfabriqué segments, the project required lifting equipment capable of handling heavy loads with ease.

Dextra’s hot-rolled barres entièrement filetées (FT) were the ideal solution to meet these requirements. Over 100 sets of FT post-tensioning bars, along with accessories like end nuts and couplers, have been supplied for lifting and launching the Préfabriqué segments using a launching girder.

Dextra FT Bar systems are commonly used in temporary applications such as heavy lifting, stitching Préfabriqué elements, and anchoring steel frame supports. For permanent applications, FT Bars are also suitable for connecting girders and jetées in segmental bridge construction.

The Zuari Bridge, a remarkable 640-meter-long, 8-lane cable-stayed bridge, spans the mighty Zuari River in Goa, West India. The project also includes 450 meters of elevated approach roads supported by just two pillars, along with a 12-kilometer detour. The total estimated value of the project is $227 million.

This new bridge will significantly reduce long commute times between the two banks of the river. With a wider span compared to its 30-year-old predecessor, it will also accommodate the increasing vehicular traffic in the region.

The Public Works Department (PWD) aims to enhance road safety and streamline traffic flow with the new structure. In addition to the bridge, two towers with viewing galleries will be incorporated for tourism purposes. The project, which began in 2016, is slated for completion in 2019.

Parallel-Threaded Rebar Couplers for Piles and Pylons

Dextra has played a pivotal role in this landmark project by supplying its renowned Bartec parallel-threaded rebar couplers for Fe 500 and Fe 600 Grade steel. Over 110,000 Bartec couplers are being used in the bridge’s pile cages and pile caps. This iconic project features Fe 600 grade steel in the pile caps and Fe 500 grade steel in piles that extend up to 48 meters deep. The bridge’s 103-meter-high pylons are also designed with Fe 600 grade steel.

Bartec couplers are a high-performance mechanical solution, ensuring no reduction in the cross-sectional area of the bars due to their parallel threads. This characteristic strengthens the rebar connections and simplifies project inventory management—one type of coupler is used for both standard and position applications.

The preparation of each rebar end is efficiently handled by three high-productivity machines, which cut, cold forge, and thread the bars in sequence.

Post-Tensioning Bars for Precast Elements and Segment Castings

In addition to the Bartec couplers, Dextra supplied post-tensioning bar systems for the bridge’s precast segments. These PT bars are crucial for ensuring timely and high-quality erection of precast segments and casting operations.

As of November 2018, over 500 sets of PT bars had been delivered for the project. Dextra supplied these bars to Dilip Buildcon for yard applications and launching operations.

For Phase III of the project, Dextra provided PT bars and accessories to NRS.

Le Pont Temburong, also known as the Sultan Haji Omar Ali Saifuddien Bridge, spans Brunei Bay in the northeast of the country. At 30 kilometers long and with four lanes, it ranks among the world’s longest sea bridges.

The bridge connects Sungai Besar et Mengkubau, providing a direct route that allows commuters to travel between the two territories without passing through Malaysia, thus bypassing the four immigration checkpoints on the congested alternative route.

Dextra contributed to this project by supplying 34,000 linear meters of Sonitec tubes for integrity testing of the foundation piles, utilizing the CSL (crosshole sonic logging) method.

Construction began in 2014, and the bridge was officially opened to traffic in 2020.

Source des images : https://www.reduper.com/industry/traffic/bridge/sea-bridge/temburong-bridge/

Le Couloir surélevé de Barapullah is a major infrastructure project in India. The primary purpose of this extension is to ease traffic congestion and provide a new express connection between Indira Gandhi International Airport and East Delhi.

Reinforcing the Elevated Road with PT Bars

For the construction of this flyover, Dextra supplied its fully-threaded post-tensioning bars, along with its well-known Bartec rebar splicing solution, to the contractor L&T Construction.

Le fully-threaded PT bar systems were used in temporary applications during the construction process. Dextra’s fully-threaded post-tensioning bars were utilized to lift and launch the precast elements of the expressway’s elevated structures.