1996 · 13 citations · 0 references
EngineeringCivil EngineeringMaterials EngineeringBridge EngineeringStructural EngineeringStructural MaterialsBridge DesignBridge RehabilitationBridge StrengtheningReinforced Concrete StructuresStructural DesignStructural RehabilitationBridge Deck StrengtheningComposite Beam StrengtheningFlexural DeformationFlexural Strength TestingFlexural TestingReinforced Concrete Beam DesignReinforced Concrete Bridge DecksStrengthening Of Concrete Bridges
The Air Force Materials Directorate of Wright Laboratory is working with Butler County in Ohio to demonstrate the feasibility of strengthening concrete beams in a bridge deck with externally-bonded carbon/epoxy composite plates. This paper describes some of the laboratory evaluations leading to the selection of acceptable materials, designs and techniques to accomplish this. The flexural response of appropriately scaled-down steel-reinforced concrete beams is determined experimentally. The adhesive system, composite lay-up, composite volume and environmental exposure were systematically varied to assist in optimizing the final design. A composite/composite lap joint was introduced at different locations in the beam to simulate field requirements for larger beams, and uniform pressure during the bonding process was achieved with a vacuum bag. The use of appropriate instrumentation allowed identification of the sequence of failure events under flexural testing. The experimental methods, test results and their comparison with control beams are presented.