The building and civil engineering sector is the most polluting sector in the Netherlands. Therefore, there is an increasing need for circular and sustainable products and processes. High demand for raw materials and high environmental pressure of this sector could be reduced by implementing the Circular Economy (CE) principles in the public procurement, which is called circular public procurement (CPP). There are different ways to circular public procurement (CPP), among which is the implementation of new business concepts such as Product-Service System (PSS). An example of a business concept that is relatively new in the Dutch infrastructure sector, is the concept of infrastructure-as-a-service, which is a type of PSS. Even though some of CE principles are incorporated in PSS, PSS does not always lead to higher circularity or environmental improvements. Therefore, in this study, the following research question is answered: Does PSS lead to a higher circularity and lower environmental pressure when implemented in the municipal procuring process of a slow traffic road? The research question was answered by performing semi-structured interviews with the experts from the field, by providing the first comparative LCA of a traditional road and its product-service alternatives, and by calculating and comparing the Material Circularity Indicator (MCI) of each alternative.

The scope of this study considers the upper layer of the road and the following life cycle stages: extraction of raw materials, transport of raw materials, production and transport of road components, use, maintenance, replacement, transport of waste and other released material, recycling and waste treatment. The function studied was the availability of 11,200 m2 of paving brick slow traffic road surface for 40 years’.

Based on the set scenarios, the LCA results showed that product-service alternatives do have significant environmental benefits over the reference system. The product-service scenarios were based on the two environmental strategies that were mentioned in both the interviews and in literature: i) extending the useful lifetime of the product and ii) reducing waste and optimizing end-of-life treatment. Relative to the baseline scenario, the biggest environmental gains and the biggest increase in circularity can be achieved when the currently downcycled material is reused or repurposed instead of recycled. By reusing all residual paving material at the end of its use, the CO2-eq emissions can be reduced by 77%, and circularity can be increased by 8%. The other two assessed improvements of the use and end-of-life phase were the reduction of breaking percentage and the increased utility of concrete components through a material passport. The last initiative led to 3% higher circularity but it did not lead to significant environmental improvements while the reduction of breaking percentage did lead to improved environmental impacts but it did not lead to a change in circularity. When combining all three initiatives, which was done in the product-service++ scenario, CO2-eq emissions can be reduced by 95%, freshwater aquatic ecotoxicity by 98% and stratospheric ozone depletion by 90%, relative to the baseline scenario. In addition, this study identifies the supply of road components that includes extraction of raw materials, production and transport as the hotspot of each alternative, which indicates the importance of material reuse. Furthermore, over the whole life cycle of each alternative, electricity was identified as the biggest contributor to the characterization results due to the high share of fossil fuels in its generation.

Even though the possible product-service scenarios lead to improved environmental performance and circularity, the results from the interviews indicated that the concept of infrastructure-as-a-service is still in its infancy and that several issues need to be addressed before it can be implemented on a large scale. The issues that need to be addressed are the separation of economic and legal ownership by law, additional burden in contract management and contractual risk inclusion. Furthermore, the concept of infrastructure-as-a-service seemed to fit more to infrastructural objects that are located in the countryside because an object in the countryside has less direct connections to other infrastructure meaning the influences from the surroundings are minimized, which poses less risk to the provision of the functional unit. Before the above-mentioned issues are solved, infrastructure-as-a-service is not recommendable. Instead, municipalities as the owner of an infrastructure should take their responsibility to properly reuse paving material.