Advanced Structural Materials and Systems (ASMS)

Our primary mission is to develop and investigate advanced structural materials and systems for use in civil infrastructure. The importance of building modern structures and renovating and conserving existing infrastructure is increasing day by day. Therefore, advanced structural materials are required to improve the load-carrying capacity and serviceability of the existing infrastructure and the design of new structures. Our research aims to make urban living more sustainable, comfortable, resilient, and functional in accordance with the UN Sustainable Development Goals (SDGs) of building sustainable cities and resilient infrastructure. Within our research area, new materials and systems are developed and studied in small and large-scale sizes to demonstrate their application feasibility for civil infrastructure. Currently, our core areas of research are:

  • Digital Fabrication and Net-Zero Construction:
    • Advanced Carbon Sequestration and Digital Construction for Net-Zero Concrete Structures
    • Digital Concrete for Design and Construction of Bridge Infrastructure with Net-Zero Emissions
    • Innovative and Advanced Slab Systems using Digital Fabrication Technologies
    • Prestressed shape memory alloy reinforcement for 3D Concrete Printing
  • Development and Characterization of High Performance Materials:
    • Eco-UHPC-VP: Eco-friendly Ultra High Performance Concrete, Volumetrically Prestressed with Fe-SMA Fibres
    • Development and Characterization of a New Generation of Fe-SMAs: Ultra-High Fe-SMA
    • Short- and long-term creep and stress relaxation of Fe-based shape memory alloys
  • Application of Advanced Materials and Structural Systems:
    • Self-centering and confining memory steel reinforcements for bridge columns
    • FRP Bogie for freight wagons-feasibility study

To achieve our missions, we strongly collaborate with national and international research and industrial partners and experts in the field, including material scientists, manufacturers, acoustic scientists, electrochemistry scientists, engineering scientists, and consulting and construction sectors. Our primary research and collaboration with the industry have already resulted in “technology transfer” and “product development”.

 

Advanced Carbon Sequestration and Digital Construction for Net-Zero Concrete Structures
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This multidisciplinary project involves synergic integration of advanced carbon sequestration and digital fabrication methods for developing next-generation net-zero concrete structures. The project will enable the digital fabrication of CO2 sequestering concrete mixtures for structural applications. It is expected that the project's outcome may lead to the development of structural elements with at least 50% less embodied CO2 emissions than the conventional structural elements. In this way, the project will pave the way to directly benefit from digitization and automation in the building and construction industry to reduce environmental impacts.

Involved staff: Saim Raza, Moslem Shahverdi

 

Project Partners:

  • ETH Zurich
  • Empa Laboratory-506, Advancing Life Cycle Assessment Group
  • Empa Laboratory-202, Corrosion & Materials Integrity Group
  • Empa Laboratory-304, Mechanical Systems Engineering
  • Iowa State University (ISU), USA
  • Carbicrete, Canada
Digital Concrete for Design and Construction of Bridge Infrastructure with Net-Zero Emissions
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To help achieve the ambitious goal of Net-Zero CO2 emissions by 2050, this large-scale multidisciplinary project aims at developing a detailed framework for design and construction of bridges with net-zero emissions. The project involves theoretical and numerical studies on alternative bridge designs using different construction materials and techniques. Specifically, the potential/suitability of materials with a low CO2 footprint and construction techniques involving reusable/digitally fabricated concrete formworks will be evaluated for bridge design and construction. The project also aims to develop criteria for assessing and quantifying CO2 neutrality and the performance of bridge structures.

Involved staff: Saim Raza, Moslem Shahverdi

Project Partners:

  • PSI - Paul Scherrer Institut
  • Eawag - Swiss Federal Institute of Aquatic Science and Technology
  • WSLS - Swiss Federal Institute for Forest, Snow and Landscape Research
Innovative and Advanced Slab Systems using Digital Fabrication Technologies
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In this cutting-edge project, digital fabrication technology will be utilized to develop innovative and advanced floor slab systems. The proposed slab system will comprise digitally fabricated concrete formwork, and cast-in-place reinforced concrete topping. The state-of-the-art post-tensioning technology by BBR VT International AG will be used to improve the structural performance of the concrete formwork. In addition, topology optimization tools will be implemented to optimize the geometry of the formwork to manufacture slabs with free-form geometries to ensure significant material savings. It is anticipated that the successful completion of this project would lead to a technological paradigm shift in the construction industry, ultimately leading to the adoption of more sustainable and technologically advanced construction methods.

Involved staff: Saim Raza, Moslem Shahverdi

Project Partners:

  • BBR VT International AG
  • ETH Zurich
  • Swiss Innovation Agency - Innosuisse, financing
Prestressed Shape Memory Alloy Reinforcement for 3D Concrete Printing
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Digital concrete fabrication with additive manufacturing techniques such as extrusion-based 3D concrete printing (3DPC) is expected to revolutionize the construction sector. However, a major obstacle to its wider implementation is the incorporation and efficient utilization of reinforcement within load-bearing 3DPC structures. Amongst the most robust reinforcement methods proposed for overcoming the weak tensile and interfacial behavior of 3DPC is prestressing, typically with post-tensioning steel tendons. This project considers a novel prestressing approach utilizing iron-based shape memory alloy (Fe-SMA) reinforcement, which has already proven very successful in strengthening conventional concrete structures under various loading scenarios. The aim is to investigate the mechanical performance and self-prestressing ability of Fe-SMA-reinforced 3DPC elements to demonstrate the feasibility of this simple but robust method for reinforcing digitally fabricated concrete.

Involved staff: Zafiris Triantafyllidis, Moslem Shahverdi

Project Partners:

  • Digital Building Technologies, ITA, ETH Zürich
  • Empa Laboratory-308, Concrete & Asphalt Laboratory
Eco-UHPC-VP: Eco-Friendly Ultra High Performance Concrete, Volumetrically Prestressed with Fe-SMA Fibres
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This project aims to develop a novel Ultra-High-Performance Fiber Reinforced Concrete (UHPFRC) mix for the next generation of sustainable concrete structures. An environmentally friendly concrete mix is under development, in which significant proportions of Portland cement are substituted with alternative binders and fillers to reduce the high carbon footprint associated with the former. In addition, this novel mix's cracking resistance and ductility are enhanced using the innovative concept of volumetric prestressing. This is accomplished by embedding randomly dispersed short fibers made of iron-based shape memory alloy (Fe-SMA), activated after concrete hardening to exert a three-dimensional prestress to the concrete matrix.

Involved staff: Zafiris Triantafyllidis, Volha Semianiuk, Mateusz Wyrzykowski, Christian Affolter, Moslem Shahverdi

 

Project Partners:

  • re-fer AG
  • Empa Laboratory-308, Concrete & Asphalt Laboratory
  • Empa Laboratory-304, Mechanical Systems Engineering Laboratory
Development and Characterization of a New Generation of Fe-SMAs: Ultra-High Fe-SMA
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In civil engineering, the formation of recovery stress after heating and cooling a strained FeMnSi-based shape memory alloy (FeMnSi-SMA) is essential to evaluate its potential as a pre-stressing element such as in concrete. Recovery stress depends on the shape memory effect (SME) and the yield stress of the FeMnSi-SMA. Different heat treatment conditions, e.g., different aging temperatures and times, lead to the formation of different number densities and sizes of precipitates, which affect the SME and yield stress. As a result, the recovery stress varies. In the first part of this project, the impact of heat treatment of an existing FeMnSi-SMA with the composition of Fe-17Mn-5Si-10Cr-4Ni-1(V, C) (mass) % on the recovery stress will be studied. Besides, in the second and third parts of the Ph.D. work, the effect of thermomechanical treatment (i.e., deformation of the FeMnSi-SMA at elevated temperature) on the recovery stress and the modification of the alloy composition to achieve better performance will be studied.

Involved staff: Yajiao Yang, Christian Leinenbach, Moslem Shahverdi

 

Project Partners:

  • BÖHLER, Austria
  • re-fer
  • CSC, China
  • ETH Zurich

 

Short- and Long-Term Creep and Stress Relaxation of Fe-based Shape Memory Alloys
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Fe-based shape memory alloy (Fe-SMA) application as prestressed reinforcements for structural strengthening and retrofitting increases with time. A typical life span of a reinforced concrete structure is in the range of 50-100 years. Therefore, time-sensitive properties such as creep and stress relaxation of reinforcement play a crucial role in determining the service life of prestressed concrete structures. A short-term recently showed a pronounced amount of creep and relaxation in Fe-SMA at low temperatures. These properties are influenced by the phases present in Fe-SMA and factors leading to transformation. However, transformation kinetics, creep and relaxation mechanism, and long-term behavior remain unknown. Thus, in this project, transformation kinetics will be investigated using an in-situ synchrotron creep and relaxation test. First, various material and application parameters influencing creep and relaxation will be studied. Later, ex-situ experiments will shed light on the long-term behavior of Fe-SMA. Subsequently, long-term data will be used to model the creep and relaxation behavior.

Involved staff: Meet Jaydeepkumar Oza, Christian Leinenbach, Moslem Shahverdi

Project Partners:

  • BÖHLER, Austria
  • re-fer
  • EPFL Laussane
Self-Centering and Confining Memory Steel Reinforcements for Bridge Columns
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RC bridge piers may witness a tilt once the earthquake load is over. This tilt can adversely affect the functionality of individual piers and the entire bridge structure by causing misalignment with the elements of the superstructure. Past research has shown that a recentering ability can be added to the bridge piers by prestressing. However, the available prestressing techniques are very cumbersome to implement. To address this challenge, an innovative and easy-to-implement technique that utilizes the unique prestressing characteristics of iron-based shape memory alloy reinforcement will be developed for self-centering and active confinement of bridge piers. The successful implementation of the project will have a tremendous societal impact with respect to keeping bridges and highway networks functional after the extreme loading events and thus ensuring smooth post-disaster response and recovery. Such applications will be studied for the first time, and the developed technique/product will be applied in a pilot project.

Involved staff: Saim Raza, Moslem Shahverdi

Project Partners:

  • re-fer AG
  • Swiss Innovation Agency - Innosuisse, financing
FRP Bogie for Freight Wagons-Feasibility Study
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Employing composite materials and structures in the railway transit systems, particularly in rail vehicles, brings several significant advantages to this industry: remarkable weight reduction, less noise emission, improved running dynamic, etc. However, the higher cost of materials and manufacturing for FRP structures is the main barrier to such FRP–metal replacements. Therefore, the focus of this project in the feasibility phase is to develop and introduce an FRP bogie concept, not only to be employed as the load-bearing component but also to be capable of integrating some functions into the bogie frame to present enhanced mechanical behavior like innovative metallic bogies (e.g., DDRS-25L).

Involved staff: Ali Saeedi, Masoud Motavalli, Moslem Shahverdi

Project Partners:

  • BAFU/BAV, Ittigen
  • PROSE, Winterthur
  • Ensinger, Otelfingen
  • Empa 509, Dubendorf
  • SBB, Basel
  • Wascosa AG, Lucerne

 

 

 

 


fib webinar by M. Shahverdi about shape memory alloys