Strengthening of Reinforced Concrete Beams Using Prestressed Glass Fiber-Reinforced Plastic

摘要

In recent years, glass fiber reinforced plastic material (GFRP) has been used as a repair to rehabilitation material for deteriorated R.C. Structures. The main topic of this paper is a study of the strengthening of reinforced concrete beams using prestressed glass fiber reinforced plastic material (PGFRP). The increase in the load capacity and the deflections in R.C. beams using GFRP and PGFRP were tested and compared. Two beam shapes, T-shaped and inverted T beams, were used as under-strengthened and over-strengthened beams in these tests. Test results show that PGFRP can be used to strengthen R.C. beams and cause no crack when the pretension is transferred. For the load capacity, the test results indicate that, for T-shaped beams, using GFRP can increase the load capacity by as much as 55percent compared with the reference beams and PGFRP can increase by 100percent. For inverted T beams, using GFRP can increase the load capacity by as much as 97percent, and PGFRP can increase by 117percent. For the deflections, at the same external loads, beams with GFRP display larger deflections than beams with PGFRP. Test results also show that using glass fiber plates to strengthen R.C. beams will decrease the displacement ductility of the beams. The over-strengthened beams have less displacement ductility than under-strengthened beams.