Development of a fully circular pontoon design by substituting EPS with a foamed carbon sequestrated geopolymer-concrete

The GeoPON project aims at developing a 100% circular pontoon free of EPS using tailored geopolymer concretes and demonstrating the impacts on performance and sustainability. In addition, and for decreasing the overall density of the pontoon, the project will also look at substituting the natural aggregates in concrete shell by high performance, low carbon and circular lightweight aggregates manufactured from industrial waste sources. As such, the innovation will lead to the design of a new product, 100% circular and with lower carbon emissions. In order to fit the pontoon specifications, the production process of the lightweight geopolymer binder and the aggregates must be optimized and tailored. The lightweight geopolymer binder is a semi-crystalline amorphous material, which is formed through the polymerization reaction between an aluminosilicate source and an alkaline reagent. It is a cement free, ultra-low carbon footprint binder allowing CO2 sequestration. The aggregates produced in the project are designed circular with a low or carbon neutral footprint through a manufacturing process enabling to tailor the aggregate properties to the user needs, and to use the geopolymer concrete as a raw material in the same manufacturing process at the end-of-life stage. To enable the integration of the circular geopolymer concrete developed in the project to the pontoon, a holistic optimization approach will be established in the project to define the best design of floating structure based on the assessments of circular concretes and the requirement on the structural performances. The approach will include design, using fluid structure interaction modelling approach, manufacturing of the pontoon, production of geopolymer and aggregates, and assessment of environmental/economic considerations.

The main objective of the project is the development of 100% circular pontoon free of EPS using tailored geopolymer concretes and demonstrate the impacts on performance and sustainability. In addition, and for decreasing the overall density of the pontoon, the project will also look at substituting the natural aggregates in concrete shell by high performance recycled particles obtained from industrial wastes. As such, the innovation will lead to the design of a new product, 100% circular, manufactured and commercialised by Helmar. The production process of the foamed geopolymer concrete and the aggregates must also be optimised and tailored to fit for the pontoon specifications, leading to a new production process for Rockpore, and new waste recycle chain for Rana Gruber. Helmar anticipates that the use of EPS might be prohibited in the future due to new regulations and is looking for alternatives. The Rockpore solution appears very appealing as a substitute for EPS: The Rockpore concept is a type of low-density geopolymer-concrete, 100% circular, using recycled Light Weight Aggregates and cement free binders. The properties of the TBG can be modified to fit end user needs, which enables market penetration in markets outside the construction sector. The present project aims at utilising and adapting the Rockpore TBG together with a unique cement free, ultra-low carbon footprint binder as a substitute to traditional EPS block in the pontoons. In addition, a new aggregate type will be developed, as a substitute to the natural aggregates used in the shell concrete. To enable the integration of the circular geopolymer concrete developed in the project to the pontoon, a holistic optimization method will be established to define the best design of floating structure based on the assessments of circular concretes and the requirement on the structural performances, and will include design, manufacturing and assessment of environmental/economic considerations.