Mechanical behavior of ultra-high toughness concrete (UHTC) tunnel segmental joints

authored by: Minjin Cai, Hehua Zhu, Qing Chen, Timon Rabczuk, Xiaoying Zhuang
Abstract: Segmental joints in tunnel linings are considered weak points due to their limited tensile strength and poor crack resistance. Ultra-high toughness concrete (UHTC) offers a solution to these issues, thanks to its exceptional tensile strength, outstanding crack resistance, and impressive durability. However, the application of UHTC in tunnel segmental joints remains underexplored. To assess its suitability, this paper conducted comprehensive full-scale tests on UHTC and traditional reinforced concrete (RC) segmental joints. The study analyzed the mechanical properties of UHTC and RC joints, including material characteristics, segmental deflection, joint behavior, bolt strain, damage propagation, and failure modes. The results showed that: (1) UHTC joints exhibited superior stable bearing capacity, exceeding that of RC joints by 25 %, with a 42 % higher initial cracking strength. (2) UHTC joints also demonstrated excellent crack control, maintaining crack widths below 0.2 mm and preserving structural integrity. In contrast, RC joints experienced extensive cracking, leading to concrete fracture and spalling. (3) UHTC joints displayed remarkable toughness, surpassing RC joints by 2.48 times during the elastic growth stage and 1.55 times in the plastic stable growth stage. Meanwhile, UHTC joints exhibited 1.47 times greater ductility than RC joints. (4) Considering multi-scale mechanical effects, UHTC joints enhanced the toughness and strength advantages of UHTC over RC by over 30 % during the elastic stage. These findings highlight the potential of UHTC in shield tunnel construction, especially in challenging environments like high ground stress areas and earthquake fault zones.
Organisation(s): Institute of Photonics
External Organisation(s): Tongji University
Bauhaus-Universität Weimar
Type: Article
Journal: Tunnelling and Underground Space Technology
Volume: 151
No. of pages: 20
ISSN: 0886-7798
Publication date: 09.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Building and Construction, Geotechnical Engineering and Engineering Geology
Electronic version(s): https://doi.org/10.1016/j.tust.2024.105838 (Access: Closed)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{98a7ea259c454e18b18f8b417bf55d28,
title = "Mechanical behavior of ultra-high toughness concrete (UHTC) tunnel segmental joints",
abstract = "Segmental joints in tunnel linings are considered weak points due to their limited tensile strength and poor crack resistance. Ultra-high toughness concrete (UHTC) offers a solution to these issues, thanks to its exceptional tensile strength, outstanding crack resistance, and impressive durability. However, the application of UHTC in tunnel segmental joints remains underexplored. To assess its suitability, this paper conducted comprehensive full-scale tests on UHTC and traditional reinforced concrete (RC) segmental joints. The study analyzed the mechanical properties of UHTC and RC joints, including material characteristics, segmental deflection, joint behavior, bolt strain, damage propagation, and failure modes. The results showed that: (1) UHTC joints exhibited superior stable bearing capacity, exceeding that of RC joints by 25 %, with a 42 % higher initial cracking strength. (2) UHTC joints also demonstrated excellent crack control, maintaining crack widths below 0.2 mm and preserving structural integrity. In contrast, RC joints experienced extensive cracking, leading to concrete fracture and spalling. (3) UHTC joints displayed remarkable toughness, surpassing RC joints by 2.48 times during the elastic growth stage and 1.55 times in the plastic stable growth stage. Meanwhile, UHTC joints exhibited 1.47 times greater ductility than RC joints. (4) Considering multi-scale mechanical effects, UHTC joints enhanced the toughness and strength advantages of UHTC over RC by over 30 % during the elastic stage. These findings highlight the potential of UHTC in shield tunnel construction, especially in challenging environments like high ground stress areas and earthquake fault zones.",
keywords = "Crack control, High toughness, Segmental joint, UHTC",
author = "Minjin Cai and Hehua Zhu and Qing Chen and Timon Rabczuk and Xiaoying Zhuang",
note = "Publisher Copyright: {\textcopyright} 2024 Elsevier Ltd",
year = "2024",
month = sep,
doi = "10.1016/j.tust.2024.105838",
language = "English",
volume = "151",
journal = "Tunnelling and Underground Space Technology",
issn = "0886-7798",
publisher = "Elsevier Ltd.",
}

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