Development and serviceability of a highway bridge deck using ultra-high performance fiber-reinforced concrete

Lightweight orthotropic steel decks are widely used in urban expressways. However, fatigue cracks occur in the orthotropic steel deck. As a result, their maintenance cost has been increasing. Considering this problem, we have developed a deck slab using ultra-high performance fiber reinforced concrete (UHPFRC), as an alternative to the steel deck slab. The own weight of the UHPFRC deck slab is almost the same as that of an orthotropic steel deck slab. A UHPFRC deck has very thin components as compared with conventional concrete deck, thus the safety of the UHPFRC deck slab was analyzed via finite element analysis, and the fatigue durability of the UHPFRC deck slab was also confirmed via a wheel running fatigue test. The authors confirmed that the durability of the UHPFRC deck slab was sufficiently high and verified the serviceability of the deck using vibration and load tests. The characteristic frequency and impact coefficient of the deck were calculated, and the result indicated low possibility of resonance between the deck and cars.