11 November 2019 | News
After an interview with Max Moerke from KWS, Cobouw magazine concluded that SADC’s and Schiphol Trade Park’s ambitions for sustainability are “not just Amsterdam bravado”. Below is a translation of Cobouw’s article, published on 11 November 2019.
Schiphol Trade Park as Europe’s circular hotspot
The 350-hectare Schiphol Trade Park styles itself as ‘the circular hotspot of Europe’. SADC’s approach to requesting tenders for its main infrastructure and the way it is currently being constructed by KWS show that this is more than just typical Amsterdam bravado.
Long before the first pile was driven, Schiphol Area Development Company (SADC N.V.) declared that Schiphol Trade Park was to be the most sustainable and innovative business park in Europe. Max Moerke, manager of KWS’s Amsterdam office, describes the way SADC called for tenders for the construction of the main infrastructure of the BREEAM certified area along the A4 as “exemplary”. “It should be as circular as possible, but it’s up to you how you do it,” is how Moerke sums up SADC’s Most Economically Advantageous Tender (MEAT) request. “In addition to a ceiling amount, the Environmental Cost Indicator (ECI) played an important role in the tender. It’s like what I call the ‘circular exposure’: the market participants were given a lot of room to demonstrate their strengths. After verification, it turned out that the KWS project team’s tender had the lowest ECI and therefore the lowest environmental impact.”
Madaster material passport
That’s undoubtedly thanks to the knowledge and experience that KWS had previously gained under the banner of VolkerWessels in high-profile projects such as PlasticRoad, Protonde (a prefab, modular roundabout using circular construction principles), and the introduction of the first fully electric lorry in the construction industry, together with Wierda Hybrid Technologies and Vrijbloed Transport. “Schiphol Trade Park is another step towards 100% circular infrastructure,” Moerke says, prefacing a long list of circular solutions that have been applied at Schiphol Trade Park in recent months. Virtually every item on the list has been strengthened, substantiated and surveyed by the Madaster Platform: with a view to future reuse, as many of the building materials as possible are being registered in this ‘materials library’, on a scale that is new to the infrastructure sector. “This gives the Schiphol Trade Park operator access to information on the specifications, lifespan and reusability of the materials used,” says Moerke.
Circularity begins with the minimal use of new raw materials, however, and the sustainable production of the materials that are purchased, Moerke continues. Take the roads in the business park, which is easily accessible via the A4 and A5 motorways and has its own railway station with fast connections to key locations such as Schiphol and the Port of Amsterdam: of the 13,000 tonnes of asphalt used, 12,000 tonnes consisted of 100% recycled asphalt produced using KWS’s HERA System. “By adding an organic rejuvenating agent obtained from pine oil to old milled asphalt, we create 100% recycled asphalt that is equivalent to ‘normal’ asphalt,” Moerke says. “Since its launch in 2017, this is the first time that this HERA asphalt, which is produced at our plant in Rotterdam via indirect heating (rather than direct heating), has been used on such a large scale.”
Another distinctive feature is the use of a total of 125 cubic metres of Miscanthus, or Elephant grass, in the kerbstones, pavement tiles and other concrete elements. “A proportion of this Miscanthus is grown on undeveloped areas of the business park,” Moerke explains. “Together with circular concrete, it’s part of Bio Bound, as the circular, biobased concrete products are called. A total of 19,500 units have been used in constructing the infrastructure at Schiphol Trade Park.”
The business park is also as circular as possible below ground, Moerke says. “Recycled concrete has been used in parts of the sewer system, namely the drains and culverts: 20% – the maximum percentage that the KOMO quality mark currently allows. The sewer pipes with a smaller diameter are not made of PVC but of PP. Thanks to this combination of materials, the main sewer has a lifespan of around 100 years.”
The aggregate (around 20,000 tonnes) and sand (around 5,000 cubic meters) that were required as a base layer were obtained entirely from the Schiphol Trade Park area. “Before the project was awarded to us, we had already identified which materials were available and where in the immediate vicinity,” Moerke says. “We immediately claimed them. It was a challenge also to use them in the design.”
SADC’s decision to choose KWS was not only due to ‘large, substantial solutions’, such as the use of recycled asphalt, biobased paving, and sand and aggregate from the surrounding area, Moerke says, but also ‘small, creative solutions’. “We considered absolutely every part of the project: can it also be circular and if so, how?”
Agreements were made with suppliers on the reduction of packaging materials, used coffee grounds collected in the site huts were given a second lease of life as a substrate in mushroom cultivation, and sophisticated logistics ensured that the number of transport kilometres was minimised. “All the lorries and other equipment also run on CO₂-saving diesel, a non-fossil, synthetic fuel made from waste products,” Moerke explains. “Compared to fossil diesel, this results in a reduction in emissions of more than 89% for CO₂, 10 to 34% for particulate matter, 5 to 37% for NOx and more than 99% for sulphur.”
Presenting its half-year figures, KWS’s parent company VolkerWessels stated that “we expect that the recent decision of the Council of State in the Netherlands on nitrogen emissions may have a significant negative effect on infrastructure and certain construction projects”. However, work at Schiphol Trade Park has not been hindered by the nitrogen issue.
Moerke expects KWS to be able to deliver the main infrastructure this year. He estimates that the rolling stock will by then have used around 150,000 litres of CO₂-saving diesel. And with newly acquired knowledge and experience, both SADC N.V. and KWS will be able to focus on further developments and projects according to circular principles. “Schiphol Trade Park demonstrates that we are on the right track,” Moerke believes. “The development of new circular materials is in full swing. With the MEAT method as a good starting point for circular tenders, it’s up to clients and market participants to tango together to develop infrastructure that will ultimately be 100% circular.”