PENINGKATAN DAYA DUKUNG DAN DAKTILITAS BALOK BETON BERTULANG DENGAN MENGGUNAKAN PERKUATAN CFRP (CARBON FIBER REINFORCED POLYMER)

Abstract

This paper presents a research on the ductility of normal-strength concrete beams which were designed under gravity load only. The beams were then strengthened with CFRP. The ductility of the strengthened beams was compared with that without CFRP. The analytical study employed the formulas proposed by Mander, Fardis, Pullido, and ACI Committee 440. The beams considered in the study were taken from a Moment Resisting Frame System (MFRS) which neglected the seismic loading. The behavior of the beam section at the column face was simulated with that at the midspan which possessed the same flexural and shear reinforcements as that at the end section. The beams were then wrapped with two layers of CFRP. The result of the experiment was the significant improvement in the curvature ductility of the beams strengthened with two-layered CFRP compared with that without CFRP. The increase in ductility was about 265 percent. The shape of the moment-curvature relation M– from the experiment was similar to that obtained from the analytical study by Mander, Fardis, Pullido, and ACI Committee 440. The curvature ductility of the beams strengthened with two-layered CFRP could reach up to beyond 30. According to Park and Paulay (1975), this value satisfies the full ductility requirement for seismic design. Thus, it can be used for strengthening the seismic-resistant structures.