Properties of Fiber Reinforced High Performance Cement Based Overlays for Orthotropic Bridge Decks

Abstract

An increasing number of steel orthotropic bridge deck require repair due to fatigue cracking. For the rib to deckplate joint, a possible solution is to reinforce the fatigue prone deck plate by replacing the asphalt wearing surface with a reinforced high strength concrete overlay. However, this process has been proven very difficult to execute and consequently has some issues regarding durability. This paper reports on high performance fiber reinforced cement based overlay solutions with gritted epoxy interlayer for a typical orthotropic deck with inadequate plate dimensions. Material characterization of three mix designs includes determination of compressive and tensile strength, and post crack behavior by CMOD registration from 3PBT. Furthermore, the steel-concrete composite action in the positive and negative bending moment zone is investigated experimentally. The test results give insight into the concrete behavior, the steel-epoxy-concrete interaction, and are used as input for a 3D finite element model of the reinforced deck under fatigue loading. The results indicate that fiber reinforced cement based overlay solutions may be a viable option for orthotropic decks with inadequate deck plate thicknesses