Smart pre-tensioning systems for A16 structures

From the disciplines of predictive engineering and geotechnical engineering, DYWIDAG's specialists are working daily to make infrastructural construction works safer, stronger and smarter. This is currently happening in the Rotterdam region, where the company is equipping seven bridge decks with various pre-tensioning systems within the framework of the A16 project. Robert Jansen, business unit manager post-tensioning within DYWIDAG Netherlands, explains the work in more detail.

With the exception of the shear structure over the Terbregseplein, DYWIDAG is providing the prestressing for all structures on the new highway route. An extensive and challenging assignment, in which the company has been involved from the tender phase. "Partly in view of the phase-by-phase realization of the project, we first of all looked intensively, together with the structural engineers, at what would be the most effective and smartest prestressing solution," Jansen reflects. "To this end, the most important reinforcement nodes were drawn out in 3D. This approach paid off in a great way. Because although the bearing surfaces of the structures may be fairly standard in character, the enormous concentration of ordinary reinforcement and prestressing systems inside makes implementation very complex. That fact, added to the phased execution, ultimately led us to make use of coupling systems, so that the bridge decks have the correct continuous prestressing. All this may take a little more time, but it certainly benefits the end result." 

600 tons of prestressing steel

Active within two of the three project subareas, DYWIDAG will contribute to the construction of a total of seven structures until the end of 2023. A total of about 600 tons of prestressing steel will be supplied for this purpose. A more than decent volume. "In subarea 1, the largest part for us, we are making six structures," says Jansen. "Some of them have already been completed. In subarea 3, Artwork 52b is on the schedule. That job, which involves driving the prestressed bridge deck into its final position in a traffic barrier, is in full swing. Without causing significant inconvenience to traffic. Apart from meeting the deadline, that is and remains of paramount importance." 

Various systems

To generate the optimal preload for each structure, DYWIDAG uses a variety of solutions. "The preloads we use range from a 12-strand system to a 27-strand system," Jansen points out the variation. "Which system we will use on site depends, among other things, on the length of the structure and the span to be made. For example, we used the 27-strand system to make a single span for an 85-meter-long bridge deck. With a length of 93 meters, the longest prestressed deck in this project awaits us soon. Despite the intermediate support point present, we will also pre-tension this structure in a single span. A nice cherry on the cake for our company during this project. A work for which we have all the necessary people and resources available."