Concrete Research and Technology
Online ISSN : 2186-2745
Print ISSN : 1340-4733
ISSN-L : 1340-4733
Fundamental Study on Crack Behavior of Bending Stress and on Improvement of Waterproof Properties of UHPFRC with Self-Healing Agent
Keishiro IriyaHideo FujiiHiroshi Koyano
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2023 Volume 34 Pages 71-82


This study was carried out on UHPFRC for repairing concrete slabs that have suffered deterioration. Waterproof properties are required for decreasing LCC. Bending tests, bending fatigue tests and water penetration tests were carried out focusing on crack behavior, especially the microcrack restraint ability in the strain hardening zone of UHPFRC. Significant strain hardening was observed in UHPFRC with 3vol% steel fiber content, with effective crack dispersal and no visually detectable cracks until 1000 μ in bottom strain. Crack width was constrained to less than 0.07 mm in a 4,800,000 cycle bending fatigue test applying 15 N/mm2 to 20 N/mm2 in bending stress. Most cracks could be healed by the self-healing agent, indicating the possibility of achieving higher waterproof performance. In light of the above, the newly developed UHPFRC can be expected to be of use as a waterproof top layer for RC slabs in future.

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© 2023 Japan Concrete Institute
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