Faserbeton im Tunnelbau

Research output: ThesisDoctoral Thesis

Abstract

For using shield machines in tunneling, segmental lining elements are used as supporting elements and inner linings. Due to a conflict in Austrian guidelines, the use of fiber reinforced segmental lining elements is not permitted. However, since fiber reinforced concrete lining elements are already being used successfully in numerous countries, the behavior of fiber reinforced segmental lining elements should be analyzed, using an extensive research program. The influence of different fiber dosages on the fresh and hardened concrete behavior was shown in initial laboratory scale mixing tests. In addition to steel fibers, plastic fibers were also used as reinforcement materials. Based on the knowledge gained from the laboratory tests, one plastic and one steel fiber mixture were used to produce in total twelve segmental lining elements in a precast concrete plant. The following loading tests provided numerous insights into the load bearing and deformation behavior of fiber reinforced segmental lining elements. The results of these tests were compared with those from the previously tests in the laboratory scale. The aim was to describe the full-scale tests by using standard laboratory tests. Another focus of the research involved the study of fiber orientation and distribution in the segmental lining element. For this analysis, drill cores were taken from fiber reinforced segmental lining elements and analyzed by using computer tomography. This was followed by a series of petrophysical and geotechnical tests on the drill cores in the laboratory to demonstrate the influence of the fiber orientation in the samples. This also included compression tests on the samples by simultaneously x-raying the samples to determine the crack development in the sample. Finally, topics regarding durability and practical usability of fiber reinforced segmental lining elements are discussed. In this context, tests were done to evaluate stray current corrosion, and the ecological aspect of fiber reinforced concrete was studied in comparison to steel rebar reinforced concrete.

Details

Translated title of the contributionFiber reinforced concrete for tunnelling
Original languageGerman
QualificationDr.mont.
Awarding Institution
Supervisors/Advisors
  • Thewes, Markus, Assessor A (external), External person
  • Gegenhuber, Nina, Co-Supervisor (internal)
  • Nguyen, Viet Tue, Assessor B (external), External person
  • Galler, Robert, Supervisor (internal)
Publication statusPublished - 2024