Concrete Bridge Decks Reinforced with Fiber-Reinforced Polymer Bars

Abstract

Corrosion of metallic reinforcement is a primary cause of reinforced concrete bridge deck deterioration. A potential innovative solution to this problem is to eliminate this corrosion by using nonmetallic fiber-reinforced polymer (FRP) bars. FRP bars consist of continuous fibers of glass (GFRP), aramid (AFRP), carbon (CFRP), or a combination of these (hybrid FRP), impregnated with and bound by a resin matrix through a pultrusion, braiding, or weaving manufacturing process. Each of these fiber types is linearly elastic to failure. Characteristics of FRP bars include electrochemical inertness, high tensile strength, low weight, low elastic modulus (primarily GFRP and AFRP), and low shear strength. For increased bridge deck service life, electrochemical inertness is the most important characteristic of FRP bars. The structural design of a concrete bridge deck with FRP top mat reinforcement is presented. The deck is supported on five prestressed concrete Type C beams. The 200-mm (8-in.) nominal-depth deck is designed for self-weight, bridge rails, overlay, MS18 (HS20) wheel loads, and bridge rail impact loads. The continuous beam analysis with distribution of force effect is based on AASHTO distribution formulas. The discussion includes required flexural strength, limits on calculated crack width, FRP bar bond stress characteristics, durability, and shear strength of the concrete deck reinforced with embedded FRP bars.