Reuse of End-of-Life Rails for Structural Elements

AI Quick Summary

Around 50,000 tonnes of rails are disposed of (sent to recycling) annually in Switzerland, instead of considering them for reuse or remanufacturing. The primary objective of the project idea is to show the feasibility of remanufacturing the rails to new scalable steel sections and to identify existing challenges and remaining problems to solve before implementation. The rails are the most loaded components of the railway system. They are made by hot rolling from carbon-manganese steel and show high strength and high durability. The typical geometries available for rails vary, but generally, a rail consists of a horizontal foot, a vertical web, and a head part, which acts as wheel tread. Most of the damage and deterioration of the rails occur in the head part. Rails are generally ground and re-shaped several times before they are disposed of because of too much material removal. Currently, around 50,000 tonnes of rails are disposed of every year in Switzerland. They are cut into pieces with a length of one meter and are then melted for the production of recycling steel. However, a closed loop for producing only new rails from old rail material does not exist. What problem would you like to solve?Recycling the material of end-of-life components is better than sending it to a landfill, but recycling should be one of the last options in the sense of a circular economy. Instead of using end-of-life rails for producing recycling steel, they can be reused in new applications in the sense of remanufacturing or repurposing. Such reuse applications of rails are considered to be possible in the form of structural elements in buildings (e.g., beams, columns, trusses), where the risk for fatigue failure is low. Because of the architectural and structural design limitations given by the existing rail profiles, remanufacturing the rails to new scalable sections is required. The rails can be reused as reclaimed or can be processed mechanically (e.g., by grinding, or by separating the eventually damaged head part from the web) in a first step. Afterward, they can be assembled into larger sections by welding, with or without adding further material (e.g., in the form of steel sheets).The project's primary objective is to show the feasibility of such applications and identify existing challenges and problems to solve before implementation. For this, a demonstrator will be designed, manufactured, tested, and evaluated. This will allow, in addition to proving the feasibility, also to identify (i) challenges in remanufacturing specific to the rail material, (ii) necessary effort for remanufacturing rails to structural elements, and (iii) open questions to be addressed before implementation. Who will benefit from your solution?The proposed solution of reusing end-of-life rails for structural elements offers benefits for different stakeholders along the supply chain. Currently, rails that cannot be reshaped anymore, are cut into one-meter-long pieces and are disposed of as scrap. If they can be reused (repurposed) for structural elements, their end-of-life value will increase and as a result of this, the owners will benefit. For steelwork contractors, the possibility of manufacturing steel sections made of reclaimed rails will extend their portfolio and allow them additional business opportunities. Moreover, such novel steel sections will also provide designers with additional alternatives to conventional sections. Finally, and probably most importantly, it will help to reduce emissions and will support the transition towards a circular built environment. Who are the existing persons/companies in your team and what is their role?The team consists of the Group of Steel and Composite Structures from the Institute of Structural Engineering (IBK) at ETH Zurich as the leading organization and research partner, and ÖBU – Verband für nachhaltiges Wirtschaften, Schneider Stahlbau AG and Weldinspect AG as implementation partners. The roles of the different partners are the following:Steel and Composite Structures, IBK, ETH Zurich – represented by Dr. Vlad Silvestru; acts as the main applicant and is responsible for designing and testing the demonstrator, as well as evaluating its performance;ÖBU – Verband für nachhaltiges Wirtschaften – represented by Dr. Alberto Cerri; responsible for coordinating the project with the RUSS network, attracting 3rd party funding, communication, and networking for extending the team as required for follow-up implementation projects;Schneider Stahlbau AG – represented by Mr. Sven Egloff; responsible for manufacturing the demonstrator, including necessary mechanical processing and welding tasks;Weldinspect AG – represented by Mr. Hubert Härtl; responsible for consulting and inspection related to the necessary welding tasks.In addition to the above persons/companies, SBB Bahntechnik Zentrum supports this project idea as a supplier of the necessary end-of-life rails. How does your challenge have a positive impact on the planet (e.g., material reduction, CO2 emission reduction?Considering the large amount of annually disposed rails (around 50,000 tonnes), the option of reusing the rails in new applications instead of recycling them will lead to reduced raw material consumption, reduced energy consumption, and a reduction of CO2 emissions. The production of one tonne of primary steel leads to around 2.3 tonnes of CO2 emissions, while in the case of recycling steel the emissions per tonne of steel reach values of around 0.6 tonnes of CO2 emissions. By using steel sections made from reclaimed rails instead of new steel sections, the amount of necessary raw materials as well as related emissions could be significantly reduced. Has your idea been tested before?In the conducted literature search no similar ideas were identified. Examples of isolated applications of end-of-life rails for fences or slope stabilizations were found, but none of them were assessed in a systematic way that would allow for new circular products and business opportunities. Therefore, the proposed idea exhibits a high degree of innovation in addition to its expected high impact on reducing raw material consumption and CO2 emissions. What are you planning on working on throughout the booster (e.g., developing the business model, building an initial prototype, material for prototyping, etc.)? What will you deliver at the end of the booster?In the booster, a demonstrator beam composed of at least two rail profiles welded together will be developed, manufactured, tested, and evaluated. The beam will be tested in four-point bending in the laboratory facilities of the research partner. Besides the structural performance evaluated from the test, life cycle and cost assessments will be performed for the beam based on the manufacturing process. Comparisons with conventionally produced steel sections will be established. Additional material tests could be conducted on uniaxial tensile test specimens manufactured from the same rail profiles used for the beam. However, preliminary data on the material properties of reclaimed rail steel is available from tests conducted by the Swiss Safety Center in collaboration with ÖBU. The different tasks to be addressed within the booster are briefly described below:T1 – Planning and manufacturing of beam made from reclaimed rails – a representative section will be selected for evaluating the feasibility of reusing/remanufacturing rails as structural elements. This structural element will be designed and manufactured to identify related challenges and provide a specimen for later testing.T2 – Experimental testing and analysis of beam made from reclaimed rails – the structural element made from end-of-life rails will be tested in the laboratory facilities of the Institute of Structural Engineering to assess its structural behavior. In addition, its performance will be compared to alternative conventionally fabricated components, based on structural design calculations and/or simulations, as well as preliminary estimations for life cycle and cost assessment. Additional necessary investigations for reusing/remanufacturing rails as structural elements will be identified and assessment approaches will be elaborated for initiating follow-up research and development.T3 – Dissemination and initiation of follow-up research and development – The findings of the booster will be used to initiate a larger follow-up project to implement reuse applications for reclaimed rails. Additional research and implementation partners will be approached, if necessary. Furthermore, it will be aimed to share the findings with practitioners and academia through conferences and publications. What are you expecting from the booster (e.g., looking for specific partners, expert support, etc.)?The booster will support the project idea in several points. First, it will provide a platform for collaboration between research and implementation partners on a promising and innovative solution for a circular economy of rails. Second, the booster will secure the necessary budget for conducting the feasibility investigations on reusing end-of-life rails for structural elements. Third, the booster is expected to also provide excellent opportunities for disseminating the findings with the relevant stakeholders from the building industry and for finding additional eventually necessary partners. How will you attract the 3rd party funding (10% of the total funding amount)?öbu has built up a "Re-Use Steel Community" over the last three years. We are receiving more and more requests for "re-use" steel; targeted preliminary discussions with industrial partners, including the infrastructure sector, make us confident that additional funding can be obtained.

Project Idea Metadata

• Project Idea Name: Reuse of End-of-Life Rails for Structural Elements
• Date: 2/6/2024 5:48:10 PM
• Administrators:
  • Vlad-Alexandru Silvestru

Project Idea Description

The rails are the most loaded components of the railway system. They are made by hot rolling from carbon-manganese steel and show high strength and high durability. The typical geometries available for rails vary, but generally, a rail consists of a horizontal foot, a vertical web, and a head part, which acts as wheel tread. Most of the damage and deterioration of the rails occur in the head part. Rails are generally ground and re-shaped several times before they are disposed of because of too much material removal. Currently, around 50,000 tonnes of rails are disposed of every year in Switzerland. They are cut into pieces with a length of one meter and are then melted for the production of recycling steel. However, a closed loop for producing only new rails from old rail material does not exist.

What problem would you like to solve?

Recycling the material of end-of-life components is better than sending it to a landfill, but recycling should be one of the last options in the sense of a circular economy. Instead of using end-of-life rails for producing recycling steel, they can be reused in new applications in the sense of remanufacturing or repurposing. Such reuse applications of rails are considered to be possible in the form of structural elements in buildings (e.g., beams, columns, trusses), where the risk for fatigue failure is low. Because of the architectural and structural design limitations given by the existing rail profiles, remanufacturing the rails to new scalable sections is required. The rails can be reused as reclaimed or can be processed mechanically (e.g., by grinding, or by separating the eventually damaged head part from the web) in a first step. Afterward, they can be assembled into larger sections by welding, with or without adding further material (e.g., in the form of steel sheets).

The project's primary objective is to show the feasibility of such applications and identify existing challenges and problems to solve before implementation. For this, a demonstrator will be designed, manufactured, tested, and evaluated. This will allow, in addition to proving the feasibility, also to identify (i) challenges in remanufacturing specific to the rail material, (ii) necessary effort for remanufacturing rails to structural elements, and (iii) open questions to be addressed before implementation.

Who will benefit from your solution?

The proposed solution of reusing end-of-life rails for structural elements offers benefits for different stakeholders along the supply chain. Currently, rails that cannot be reshaped anymore, are cut into one-meter-long pieces and are disposed of as scrap. If they can be reused (repurposed) for structural elements, their end-of-life value will increase and as a result of this, the owners will benefit. For steelwork contractors, the possibility of manufacturing steel sections made of reclaimed rails will extend their portfolio and allow them additional business opportunities. Moreover, such novel steel sections will also provide designers with additional alternatives to conventional sections. Finally, and probably most importantly, it will help to reduce emissions and will support the transition towards a circular built environment.

Who are the existing persons/companies in your team and what is their role?

The team consists of the Group of Steel and Composite Structures from the Institute of Structural Engineering (IBK) at ETH Zurich as the leading organization and research partner, and ÖBU – Verband für nachhaltiges Wirtschaften, Schneider Stahlbau AG and Weldinspect AG as implementation partners. The roles of the different partners are the following:

• Steel and Composite Structures, IBK, ETH Zurich – represented by Dr. Vlad Silvestru; acts as the main applicant and is responsible for designing and testing the demonstrator, as well as evaluating its performance;
• ÖBU – Verband für nachhaltiges Wirtschaften – represented by Dr. Alberto Cerri; responsible for coordinating the project with the RUSS network, attracting 3rd party funding, communication, and networking for extending the team as required for follow-up implementation projects;
• Schneider Stahlbau AG – represented by Mr. Sven Egloff; responsible for manufacturing the demonstrator, including necessary mechanical processing and welding tasks;
• Weldinspect AG – represented by Mr. Hubert Härtl; responsible for consulting and inspection related to the necessary welding tasks.

In addition to the above persons/companies, SBB Bahntechnik Zentrum supports this project idea as a supplier of the necessary end-of-life rails.

How does your challenge have a positive impact on the planet (e.g., material reduction, CO2 emission reduction?

Considering the large amount of annually disposed rails (around 50,000 tonnes), the option of reusing the rails in new applications instead of recycling them will lead to reduced raw material consumption, reduced energy consumption, and a reduction of CO₂ emissions. The production of one tonne of primary steel leads to around 2.3 tonnes of CO₂ emissions, while in the case of recycling steel the emissions per tonne of steel reach values of around 0.6 tonnes of CO₂ emissions. By using steel sections made from reclaimed rails instead of new steel sections, the amount of necessary raw materials as well as related emissions could be significantly reduced.

Has your idea been tested before?

In the conducted literature search no similar ideas were identified. Examples of isolated applications of end-of-life rails for fences or slope stabilizations were found, but none of them were assessed in a systematic way that would allow for new circular products and business opportunities. Therefore, the proposed idea exhibits a high degree of innovation in addition to its expected high impact on reducing raw material consumption and CO₂ emissions.

What are you planning on working on throughout the booster (e.g., developing the business model, building an initial prototype, material for prototyping, etc.)? What will you deliver at the end of the booster?

In the booster, a demonstrator beam composed of at least two rail profiles welded together will be developed, manufactured, tested, and evaluated. The beam will be tested in four-point bending in the laboratory facilities of the research partner. Besides the structural performance evaluated from the test, life cycle and cost assessments will be performed for the beam based on the manufacturing process. Comparisons with conventionally produced steel sections will be established. Additional material tests could be conducted on uniaxial tensile test specimens manufactured from the same rail profiles used for the beam. However, preliminary data on the material properties of reclaimed rail steel is available from tests conducted by the Swiss Safety Center in collaboration with ÖBU. The different tasks to be addressed within the booster are briefly described below:

• T1 – Planning and manufacturing of beam made from reclaimed rails – a representative section will be selected for evaluating the feasibility of reusing/remanufacturing rails as structural elements. This structural element will be designed and manufactured to identify related challenges and provide a specimen for later testing.
• T2 – Experimental testing and analysis of beam made from reclaimed rails – the structural element made from end-of-life rails will be tested in the laboratory facilities of the Institute of Structural Engineering to assess its structural behavior. In addition, its performance will be compared to alternative conventionally fabricated components, based on structural design calculations and/or simulations, as well as preliminary estimations for life cycle and cost assessment. Additional necessary investigations for reusing/remanufacturing rails as structural elements will be identified and assessment approaches will be elaborated for initiating follow-up research and development.
• T3 – Dissemination and initiation of follow-up research and development – The findings of the booster will be used to initiate a larger follow-up project to implement reuse applications for reclaimed rails. Additional research and implementation partners will be approached, if necessary. Furthermore, it will be aimed to share the findings with practitioners and academia through conferences and publications.

What are you expecting from the booster (e.g., looking for specific partners, expert support, etc.)?

The booster will support the project idea in several points. First, it will provide a platform for collaboration between research and implementation partners on a promising and innovative solution for a circular economy of rails. Second, the booster will secure the necessary budget for conducting the feasibility investigations on reusing end-of-life rails for structural elements. Third, the booster is expected to also provide excellent opportunities for disseminating the findings with the relevant stakeholders from the building industry and for finding additional eventually necessary partners.

How will you attract the 3rd party funding (10% of the total funding amount)?

öbu has built up a "Re-Use Steel Community" over the last three years. We are receiving more and more requests for "re-use" steel; targeted preliminary discussions with industrial partners, including the infrastructure sector, make us confident that additional funding can be obtained.

Around 50,000 tonnes of rails are disposed of (sent to recycling) annually in Switzerland, instead of considering them for reuse or remanufacturing. The primary objective of the project idea is to show the feasibility of remanufacturing the rails to new scalable steel sections and to identify existing challenges and remaining problems to solve before implementation.