UHPC: a Durable Concrete Overlay Solution for Bridge Decks

The key to designing and constructing longer-lasting bridges is through the use of more durable materials. Ultra-high performance concrete (UHPC) is an emerging technology used in bridge infrastructure projects across North America, Europe, and Asia. UHPC is an engineered cementitious fiber-reinforced composite with exceptional strength and durability due to its densely packed matrix, discontinuous pore structure, and micro- crack control. These characteristics significantly delay typical concrete deterioration mechanisms in UHPC. For this reason, bridge specifiers are more frequently including UHPC into their designs. One application of particular interest is the use of UHPC as a thin-bonded, structurally-composite overlay at the surface of the bridge deck. This topping layer provides a riding surface that is both abrasion resistant and virtually impermeable and will protect the conventional materials and elements underneath. Additionally, this layer can be used as a strengthening technique to increase the live load carrying capacity of the existing structure. This solution is being deployed on both new and existing bridges as a rehabilitation strategy and to provide long-term protection to the deck.