Periodic Reporting for period 2 - GeoRes (Geomaterials: from Waste to Resource)
Reporting period: 2020-03-01 to 2023-08-31
Geomaterial waste represents half of the total waste volume generated in EU-27. In general, these waste geomaterials exhibit poor engineering characteristics and/or specific mineralogical composition that prevent their direct reuse on construction/mining sites. However, if adequately treated, they could represent an excellent resource for construction projects with significant money saving and reduction in the environmental footprint, thus contributing to the establishment of a circular economy.
To achieve this, the GeoRes Project focused on developing innovative solutions for the reuse of waste geomaterials generated by construction and mining industries across Europe and worldwide. This involved development of protocols to improve the engineering characteristics of waste geomaterials, and to guarantee the level of performance over the service life of geo-structures built from waste geomaterials considering site-specific conditions (climate, water table, leaching, weathering, hazardous compounds, etc.). A number of strategies and tools were developed for sustainable reuse of waste geomaterials generated by geoengineering activities, and to determine how to turn a waste geomaterial into a valued durable material, with a positive revenue stream.
To achieve this, the GeoRes Project focused on developing innovative solutions for the reuse of waste geomaterials generated by construction and mining industries across Europe and worldwide. This involved development of protocols to improve the engineering characteristics of waste geomaterials, and to guarantee the level of performance over the service life of geo-structures built from waste geomaterials considering site-specific conditions (climate, water table, leaching, weathering, hazardous compounds, etc.). A number of strategies and tools were developed for sustainable reuse of waste geomaterials generated by geoengineering activities, and to determine how to turn a waste geomaterial into a valued durable material, with a positive revenue stream.
A number of test sites were identified and the waste geomaterials to be used were selected for testing the mechanical and transfer properties. Several soils were selected to cover a wide range of plasticity index, and to be representative of a variety of contexts. For the stabilisers, standardised products like lime or cement, and also stabilisers containing large amounts of by-products from industry, like fly ash and calcium carbide were considered.
The pandemic has impacted the project developpment and several secondments have been canceled vith short notice.
Progress in different work packages:
WP1: Mechanical behaviour of treated waste-geomaterials
WP1 primarily focused on the durability of the mechanical performances of upgraded waste-geomaterials as a function of the context, site conditions, climate, etc. The goal of WP1was to uncover the key mechanisms which control alteration of mechanical properties of upgraded waste-geomaterials in several contexts. The first step of the implementation of the project was the identification and selection of soils, stabilising agents and test sites. An analysis of existing data on a limited number of materials and sites, based on the experience of each partner, was accomplished. Several actions were then defined, each connected to a given context of application / type of material. The actions were connected to:
1. Impact of wetting and drying cycles.
2. Behaviour of lightweight cemented soils.
3. Multiphysical couplings in compacted and treated unsaturated soils.
4. Thermo-hydro-mechanical interaction between the climate and geomaterials.
5. Behaviour of fine-grained soil stabilised with fly ash and alkali activators.
WP2: Durability of transfer performance of treated waste geomaterials
The goal of WP2 was to uncover the key mechanisms which control alteration of transfer properties of upgraded waste-geomaterials in several contexts, in order to develop general recommendations and guidelines to promote durability of transfer properties of upgraded waste geomaterials. The first step of the implementation of the project was the identification and selection of soils, amendments and test sites. The actions in WP2 were:
1. Use of Green Liquor Dregs (GLD) for soil improvement to construct sealing layer. Three sites in Sweden are investigated.
2. Amendment of sulphide bearing soil to mitigate the effect of oxidation.
3. Effect of water percolation on slope stability.
4. Assessment of regulatory barriers to the use of upgraded geomaterials.
5. Design and optimisation of water distribution systems to improve heap leaching.
WP3: Advanced constitutive, physical and numerical modelling
WP3 was focused on developing new constitutive and numerical modelling and decision support tools that can be employed in the analysis, design and construction stages to predict the long-term behaviour of improved waste geomaterials. This WP contributed to the development of solutions and tools to better understand and predict the behaviour of treated waste geomaterials and hence improve/enhance their use in engineering practice.
The first step of the implementation of the project was the identification and selection of soils, stabilising agents and test sites, as well as development of frameworks for the numerical and constitutive modelling tools. The actions in WP3 were:
1. The use of machine learning algorithms to describe the constitutive behaviour of stabilized soils for implementation in a self-learning finite element method (FEM) applied to field testing/monitoring.
2. Experimental, constitutive and numerical modelling of soils stabilized with fly ash, calcium carbide and alkali activators.
3. Effects of chitosan biopolymer on stabilization of sandy soil.
4. Decision support system for the management of excavated waste geomaterials.
The pandemic has impacted the project developpment and several secondments have been canceled vith short notice.
Progress in different work packages:
WP1: Mechanical behaviour of treated waste-geomaterials
WP1 primarily focused on the durability of the mechanical performances of upgraded waste-geomaterials as a function of the context, site conditions, climate, etc. The goal of WP1was to uncover the key mechanisms which control alteration of mechanical properties of upgraded waste-geomaterials in several contexts. The first step of the implementation of the project was the identification and selection of soils, stabilising agents and test sites. An analysis of existing data on a limited number of materials and sites, based on the experience of each partner, was accomplished. Several actions were then defined, each connected to a given context of application / type of material. The actions were connected to:
1. Impact of wetting and drying cycles.
2. Behaviour of lightweight cemented soils.
3. Multiphysical couplings in compacted and treated unsaturated soils.
4. Thermo-hydro-mechanical interaction between the climate and geomaterials.
5. Behaviour of fine-grained soil stabilised with fly ash and alkali activators.
WP2: Durability of transfer performance of treated waste geomaterials
The goal of WP2 was to uncover the key mechanisms which control alteration of transfer properties of upgraded waste-geomaterials in several contexts, in order to develop general recommendations and guidelines to promote durability of transfer properties of upgraded waste geomaterials. The first step of the implementation of the project was the identification and selection of soils, amendments and test sites. The actions in WP2 were:
1. Use of Green Liquor Dregs (GLD) for soil improvement to construct sealing layer. Three sites in Sweden are investigated.
2. Amendment of sulphide bearing soil to mitigate the effect of oxidation.
3. Effect of water percolation on slope stability.
4. Assessment of regulatory barriers to the use of upgraded geomaterials.
5. Design and optimisation of water distribution systems to improve heap leaching.
WP3: Advanced constitutive, physical and numerical modelling
WP3 was focused on developing new constitutive and numerical modelling and decision support tools that can be employed in the analysis, design and construction stages to predict the long-term behaviour of improved waste geomaterials. This WP contributed to the development of solutions and tools to better understand and predict the behaviour of treated waste geomaterials and hence improve/enhance their use in engineering practice.
The first step of the implementation of the project was the identification and selection of soils, stabilising agents and test sites, as well as development of frameworks for the numerical and constitutive modelling tools. The actions in WP3 were:
1. The use of machine learning algorithms to describe the constitutive behaviour of stabilized soils for implementation in a self-learning finite element method (FEM) applied to field testing/monitoring.
2. Experimental, constitutive and numerical modelling of soils stabilized with fly ash, calcium carbide and alkali activators.
3. Effects of chitosan biopolymer on stabilization of sandy soil.
4. Decision support system for the management of excavated waste geomaterials.
The in situ and laboratory testing campaigns provided data on the behaviour of different treated soils. These data were used to study various mechanical and transfer properties of treated soils, develop material constitutive models for treated soils, and develop, calibrate and apply numerical models to predict the short- and long-term behaviour of upgraded waste geomaterials. Innovative physical, constitutive, and numerical modelling tools and techniques were developed that can be used to better understand and predict various aspects of behaviour of treated soils at design and construction and during their service life.
The impacts of the project include:
- A number of new research collaborations were develoed, enhancing the potential and future career perspectives of the staff members through collaboration with leading researchers and practitioners in the GeoRes network. These resulted from the intersectoral and/or international secondments and the networking activities.
- A number of opportunities were identified/exploited for new joint research proposals. New research proposals have been developed or are being developed by members of the GeoRes networks. These include a doctoral training network proposal submitted in 2022, a Royal Academy of Engineering proposal developed to be submitted in September 2023.
Self-sustainability of the partnership after the end of the project. The detailed knowledge of the research infrastructure of each of the participating teams acquired in the course of the exchanges will help set up future joint research projects.
- A spin-out company is being set up as a direct results of the secondments in the project.
- A new 3D concrete printing lab has been designed at Exeter that will use waste geomaterials as partial replacement for cement.
Contribution to the improvement of the research and innovation potential within Europe and worldwide.
The participants’ expertise in experimental modelling, numerical modelling, theoretical modelling, different areas of geotechnics, geoenvironmental engineering, geochemistry, mining and different fields of application (compacted soils, reuse of mine tailings, reuse of sediments/dredged soils, mass stabilisation, etc) provides a basis for new knowledge and technological development.
The impacts of the project include:
- A number of new research collaborations were develoed, enhancing the potential and future career perspectives of the staff members through collaboration with leading researchers and practitioners in the GeoRes network. These resulted from the intersectoral and/or international secondments and the networking activities.
- A number of opportunities were identified/exploited for new joint research proposals. New research proposals have been developed or are being developed by members of the GeoRes networks. These include a doctoral training network proposal submitted in 2022, a Royal Academy of Engineering proposal developed to be submitted in September 2023.
Self-sustainability of the partnership after the end of the project. The detailed knowledge of the research infrastructure of each of the participating teams acquired in the course of the exchanges will help set up future joint research projects.
- A spin-out company is being set up as a direct results of the secondments in the project.
- A new 3D concrete printing lab has been designed at Exeter that will use waste geomaterials as partial replacement for cement.
Contribution to the improvement of the research and innovation potential within Europe and worldwide.
The participants’ expertise in experimental modelling, numerical modelling, theoretical modelling, different areas of geotechnics, geoenvironmental engineering, geochemistry, mining and different fields of application (compacted soils, reuse of mine tailings, reuse of sediments/dredged soils, mass stabilisation, etc) provides a basis for new knowledge and technological development.