Laboratory Investigations on the Repair of GFRP-Reinforced Concrete Bridge deck Slabs

摘要

Recently, the non-corrodible fibre reinforced polymer (FRP) reinforcing bars, especially glass FRP bars, have been increasingly used in concrete bridge deck slabs. Although corrosion of steel reinforcement in a major cause of a bridge deterioration, almost every bridge component requires some kind of repair/rehabilitation due to various kinds of damage or changed circumstances such as freeze-thaw and wet-dry damage, accidental (vehicle) damage, excessive cracking, poor design details, poor quality construction, inadequate maintenance, changes in level of service, etc. Therefore, there have been concerns regarding the feasibility and economics of repairing concrete elements reinforced with FRP materials. This paper presents an experimental study on the rehabilitation of concrete bridge deck slabs reinforced with GFRP internal reinforcement. The main objectives of this study are to (1) determine the most suitable concrete demolition method causing minimal or no damage to GFRP bars used as main reinforcement in concrete slabs; (2) evaluate the most effective repair technique by verifying the flexural strength and load-transfer efficiency of concrete slabs after repair. To fulfil these objectives, 16 full-scale concrete slabs (1500x2250x200 mm) totally reinforced with GFRP bars were constructed and tested in the laboratory. The test parameters include concrete demolition technique, type of GFRP bars, concrete compressive strength, number of reinforcement layers, thickness of concrete cover, and repair technique. It is concluded that GFRP-reinforced deck slabs can be easily and effectively repaired.