Framework renovation Second Petroleum Port Rotterdam

Introducing new types of concrete is a long-term process. Patrice Nederhorst knows that better than anyone else. He is Port engineer and responsible for the overall technical input in development projects in the Rotterdam port area. In that capacity, Nederhorst is one of the driving forces behind the application of cementless concrete in the Rotterdam ports and closely involved in the geopolymer concrete quay wall in the Tweede Petroleumhaven. "It's a successful experiment, we can start scaling it up," he said.

Rotterdam wants its port to be climate neutral by 2050, without losing its competitive position. The Port Authority is working towards this on many fronts, including the production of element paving from dredged sediment, the use of recycled aggregates, the reuse as much as possible of released materials such as tubular piles and footbridges and the purchase of emission-free vessels. A big step can be taken by using cementless concrete. The Port Authority alone is responsible for 80 kilometers of quay wall and 200 kilometers of slope, and the maintenance and replacement of these require a lot of concrete. Geopolymer concrete can play a major role in this. Alternatives that provide as much CO2 reduction (50%) are not (yet) available. 

The deployment of geopolymer concrete in the Port of Rotterdam is proceeding incrementally and according to the rules. "Building the quay an sich is the culmination of a process of years," says Nederhorst. "That started with an extensive laboratory study of a wide range of concrete parameters by SGS Intron. Later, shear force tests were conducted at the University of Ghent under the direction of Professor Steffen Grünewald. Based on the laboratory tests, we gave the green light to carry out a first trial pour and to build a mock-up. SGS Intron in turn performed a variety of additional tests on this and recorded this in a report, which defined the main performance of the geopolymer mixture. All this was done in close cooperation with binder supplier Sqape and concrete producer A. Jansen. The Port Authority then initiated long-term monitoring on the concrete of the mock-ups, among other things."

Then it was time for the real thing: the new quay at the Second Petroleum Port. "In fact, this is another scale-up of the trial," Nederhorst continued. "Of the 250 meters of quay, one hundred meters of quay were made with geopolymer concrete. Again, SGS Intron is providing the monitoring and reporting, being able to compare traditional cement concrete and geopolymer concrete side by side. By taking a thorough approach to the whole process and working with an independent party for testing and reporting, we achieve a number of things. First, for a similar application, retesting is not necessary. Second, with this comprehensive comparison, we want to demonstrate to permittees and certifiers that the performance compared to traditional concrete is at least equivalent and sometimes better. In particular, in terms of chloride penetration, the concrete performs so well that an application in marine conditions seems a logical choice. Third, the thorough approach gives us the feeling that we are on the right track."

Nederhorst describes the current level of development of this concrete as the vestibule to fully certified. "Until there are regulations, we have an agreement with Building and Housing Control that if we use the same mixture, we make a risk assessment for each project about the performance of geopolymer concrete compared to regular concrete. Where it deviates, we describe what we do with that deviation. If the Netherlands wants to use it, they will have to go to the competent authority themselves, but retesting seems unnecessary to me in view of all the information available. The application in the Second Petroleum Harbour is a light structural application. Constructions to moor ships go a little further. So we have established a roadmap to scale up application of geopolymer concrete. And it's open source information. All the reports from the lab tests and from the test pour of the execution phase are available to anyone. We are going full speed ahead with it and hope others will follow our example."