Abstract
Lightweight orthotropic steel decks are widely used in the bridges of an urban expressway in Japan. However, it is observed in the existing bridges that fatigue cracks occur in the orthotropic steel deck. As a countermeasure of this problem, we have developed a light weight highway-bridge deck with high durability using ultra-high strength fiber-reinforced concrete (UFC). Developed UFC deck slab consists slab of 40 mm thickness and ribs of 83 mm in height. This deck slab has an extremely thin thickness as compared to that in the concrete deck slabs. We also verified its fatigue resistance and mechanical characteristic using the wheel running test. We verified from the tests that the fatigue resistance of the UFC deck and feasibility for its application. We conducted a wheel running test to evaluate the fatigue performance of the deck, in which a wheel load was applied 200,000 times (100,000 cycles), and the magnitude was varied from 100 kN to 220 kN. As the result, there was no damage under the design load. When a load roughly two times larger than the design load was applied, minor cracks were detected on the side faces of the ribs. However, there was no reduction of stiffness. We confirm that the fatigue resistance of the UFC deck is sufficiently high.
