Influence of Steel Fiber Characteristic Parameters and Forming Methods on Tensile Performance of Ultra-high Performance Concrete
To explore the mechanical properties of ultra-high performance concrete (UHPC) with different steel fibers under uniaxial tension, we designed ten sets of uniaxial tensile tests on dog-bone-shaped UHPC specimens. We investigated how the aspect ratio (37, 50, 64, 65), dosage (2%, 3%, 4%), shape (end-...
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| Main Author: | |
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| Format: | Article |
| Language: | zho |
| Published: |
Editorial Office of Journal of Changjiang River Scientific Research Institute
2025-04-01
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| Series: | 长江科学院院报 |
| Subjects: | |
| Online Access: | http://ckyyb.crsri.cn/fileup/1001-5485/PDF/1735279977778-785781858.pdf |
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| Summary: | To explore the mechanical properties of ultra-high performance concrete (UHPC) with different steel fibers under uniaxial tension, we designed ten sets of uniaxial tensile tests on dog-bone-shaped UHPC specimens. We investigated how the aspect ratio (37, 50, 64, 65), dosage (2%, 3%, 4%), shape (end-hooked and curved), and forming methods(mixing and slurry) of steel fibers affect the tensile strength, stress-strain curves, tensile toughness, and failure process of UHPC. Results reveal that as the aspect ratio of hooked steel fiber rises, the tensile strength of UHPC increases by 6.54%-9.37%, and the residual strength ratio in the strain-softening segment grows by 5.00%-38.30%. When the volumetric dosage of end-hooked steel fiber increases from 2% to 3% and 4%, the tensile strength, peak strain, and residual strength ratio in the strain-softening segment of UHPC increase, along with an enhancement in tensile toughness. Compared with specimens formed by the mixing method, those formed by the slurry method with end-hooked steel fibers show no significant change in strength, but the peak strain increases by 53.61%-91.96%. The stress-strain curve of UHPC with curved steel fibers demonstrates strain-hardening characteristics, and its failure process involves the propagation of multiple cracks. In comparison to specimens with end-hooked steel fibers of the same aspect ratio, UHPC with curved steel fibers exhibits a 19.41-19.96-fold increase in peak tensile strain and an 18.00%-70.03% increase in the residual strength ratio in strain-softening segment. This indicates that the toughening effect of curved steel fibers is superior to that of end-hooked steel fibers. By using the hardening index and the residual strength ratio in the strain-softening segment, we can comprehensively evaluate the strain-hardening characteristics before peak axial-tensile strain and the axial-tensile toughness after peak in UHPC. |
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| ISSN: | 1001-5485 |