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Home

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Research

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Teaching

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Featured projects and achievements

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● Two major intertwined questions of elastic limit tensile stress of UHPFRC

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i) Suggested and validated a reliable method for determining the elastic limit, which has been adopted in the Swiss UHPFRC standard (SIA 2052).

ii) Identified the significant influence of fibers on matrix tensile strength, and developed an original model relating the elastic limit to fiber parameters. This model catalyzed key advancements in UHPFRC technology, including criteria for achieving strain-hardening behavior and the development of a tensile fatigue model for UHPFRC.

Two tensile stress–strain models in international standards

                       *Elastic limit tensile stress model*

Relevant Publications:

[1] J. Zhan*, E. Denarié & E. Brühwiler. Elastic limit tensile stress of UHPFRC: method of determination and effect of fiber orientation. Cement and Concrete Composites 140 (2023): 105122. https://doi.org/10.1016/j.cemconcomp.2023.105122

[2] I. Bayane, J. Zhan* & E. Brühwiler. Exploration of fracture mechanism of UHPFRC by acoustic Emission, DIC and magnetoscopy testing. Cement and Concrete Research 197 (2025): 107984. https://doi.org/10.1016/j.cemconres.2025.107984

[3] J. Zhan*, E. Denarié and E. Brühwiler. Influence of Fiber Orientation on the Elastic Limit Tensile Stress of UHPFRC. Third International Interactive Symposium on Ultra-High Performance Concrete 2023, Wilmington, USA, 2023. https://doi.org/10.21838/uhpc.16742

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● Tensile fatigue of UHPFRC materials and structures

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Revealed the governing mechanisms of tensile fatigue in UHPFRC and steel rebar reinforced-UHPFRC, using five advanced measurement techniques (e.g., magnetoscopy, acoustic emission, and fiber optic sensing).

Developed reliable fatigue design models and guidelines for UHPFRC and reinforced-UHPFRC members, which have been adopted in the Swiss UHPFRC standard, the first globally to explicitly address UHPFRC fatigue. These models are being considered in standard development in North America (ACI 239C) and China.

Tensile fatigue model of UHPFRC for typical structural applications

Tensile fatigue model of steel rebar reinforced-UHPFRC for typical structural applications

Relevant Publications:

[1] E. Brühwiler* and J. Zhan. Fatigue behavior of UHPFRC and its implementation for design. UHPFRC 2024: Ultra High Performance Fiber Reinforced Concrete International Symposium, Menton, France, 2024. https://doi.org/10.5075/epfl.20.500.14299/242030

[2] J. Zhan*, I. Bayane, E. Brühwiler & A. Nussbaumer. Deciphering tensile fatigue behavior of UHPFRC using magnetoscopy, DIC and acoustic emission. Cement and Concrete Research 196 (2025): 107924. https://doi.org/10.1016/j.cemconres.2025.107924

[3] J. Zhan*, A. Nussbaumer & E. Brühwiler. High cycle tensile fatigue behavior of steel rebar reinforced-UHPFRC at High R-Ratio. International Journal of Fatigue (2024): 108749. https://doi.org/10.1016/j.ijfatigue.2024.108749

[4] J. Zhan*, A. Nussbaumer & E. Brühwiler. Influence of fiber orientation on the high cycle tensile fatigue resistance of UHPFRC. International Journal of Fatigue (2024): 108103. https://doi.org/10.1016/j.ijfatigue.2023.108103