ProGeo-UP: Product stewardship through closed-loop geosynthetics

Geosynthetics gain in importance

In addition to mineral building materials, plastics have been increasingly used in construction worldwide since the 1960s. One relevant segment is geosynthetics (GEOK), which are mainly used in hydraulic engineering, earthworks, and foundations, as well as in landfill and tunnel construction and groundwater protection - in various functions such as filtration, sealing or stabilization.

They account for less than five percent of the total mass of a structure and have a high sustainability potential. For example, leaner construction methods can replace large quantities of mineral fractions, concrete and steel, and use locally available building materials of inferior quality. For example, CO2 emissions can be reduced by up to 90 percent. Construction time is also reduced. As GEOK mineral mixes are currently still disposed of in incinerators after deconstruction, there is a great need for recycling.

Closing the loop completely

The project “ProGeo-UP” aims to create the conditions for full recycling within five years. In addition to the reuse of selected products, the aim is to achieve recycling at the highest quality level. This means that new GEOK products will be made from recycled materials.

To this end, dismantling techniques for recovering the installed GEOK are being developed and tested based on three large-scale trials. In addition, the logistics systems, and processes to enable the material recycling of GEOK will be developed. The cycle will be set up in a robust manner to ensure a high, homogeneous, and standardized quality level of GEOK from secondary materials in the long term. To this end, the necessary administrative and regulatory framework, such as standardization, will be developed. Based on a standardized knowledge on the life cycle of the products, quality assurance mechanisms will be established to enable the comprehensive recycling and use of high quality secondary materials from GEOK. Economic and environmental indicators developed during the project will be used to establish sustainable business models for this product group.

Wide range of applications for the solutions

The “ProGeo-UP” researchers work in the following division of labour: The Resources working group of IWARU coordinates the overall project and deals with the processing technology and the analysis of the material flows generated at the various stages of the value chain. The infrastructure working group of IWARU will look at the dismantling process and analyze the environmental and economic indicators over the life cycle to develop a business model. The RUB is responsible for setting up structures to collect relevant data on the value creation stages (material passport) and linking them to the relevant stakeholders. Two of Europe's leading manufacturers of GEOK, NAUE and HUESKER, are participating in the joint project. IBH provides access to specific construction projects, including design details. TIBATEK specializes in attachments for the installation and removal of geosynthetics. TAILORLUX GmbH develops marking materials and sensor technology for quality and process assurance of plastics, and LINDNER & USG, two renowned manufacturers of processing units, complete the joint project. Other associated partners, such as the Institute for Materials Applications at the TH Köln, are also providing support.

Progress and Results of the First Project Phase (Status April 2025)

In the “ProGeo-UP” project, significant progress was made in the first project phase for the closed-loop recycling of geosynthetics (GSY). An important milestone was the first successful large-scale trial in the fall of 2024, in which innovative removal and processing methods were tested on a practical scale. The project partners HUESKER and NAUE installed different GSY on a test area of 3,200 m² and then completely removed them again using the newly developed attachment from TIBATEK. With previous techniques, GSY are removed in a disorganized manner and are often fragmented, so that any plastic residues remaining in the soil must be laboriously collected and it is not possible to reuse the material. With the new attachment, on the other hand, non-destructive recovery is possible and the rolled-up GSY can be installed and removed several times. 

In the second stage of the large-scale trial, the dismantled materials were shredded in two stages using mobile shredding units and further processed into pure plastic agglomerate in a processing plant. Seven fractions of different PP/PET-GSY products with varying degrees of contamination were tested. All materials were successfully processed, providing the basis for further material recycling. The first measurements were carried out on GSY samples using a newly developed VIR/NIS handheld device from Tailorlux. On the one hand, this technology enables detailed quality and process assurance via tracers, but on the other hand, it is also intended to provide decision-making aids by detecting the degree of contamination on site, which will enable comprehensive recycling and compliance with the requirements for high-quality secondary materials.

Two further large-scale trials are planned for the second half of the project, in which the aim is to optimize dismantling techniques and recycling approaches. Based on the knowledge gained, a comprehensive dismantling concept and a sustainable business model for the use of dismantled GSY will be developed. The model developed by RUB is a digital twin of the life cycle for constructions with GSY and will play an important role in the ongoing project.