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

verfasst von
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.

Organisationseinheit(en)
Fakultät für Mathematik und Physik
Externe Organisation(en)
Tongji University
Bauhaus-Universität Weimar
Typ
Artikel
Journal
Tunnelling and Underground Space Technology
Band
151
Anzahl der Seiten
20
ISSN
0886-7798
Publikationsdatum
09.2024
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Bauwesen, Geotechnik und Ingenieurgeologie
Elektronische Version(en)
https://doi.org/10.1016/j.tust.2024.105838 (Zugang: Geschlossen)