PENGARUH PENGGUNAAN CARBON FIBER REINFORCED PLATE TERHADAP PERILAKU LENTUR STRUKTUR BALOK BETON BERTULANG

Strengthening of reinforced concrete beam can be developed by using steel plate or carbon fiber reinforced plate (CFRP) on the tension concrete fiber as an external reinforcement. Experimental study on reinforced concrete strengthening with CFRP has been conducted to estimate the effectiveness of using CFRP on the concrete structure as flexural strengthening material and external reinforcement. In this research, three specimens were tested. The first specimen is the reinforced concrete beam with single steel reinforcement (BT), which is used as control beam. The second specimen is the reinforced concrete beam with single steel reinforcement and laminated CFRP (BTF). The last specimen is the concrete beam with laminated CFRP without steel bar (BF). The second and third beam, CFRP laminated on the bottom of beam with epoxy. Dimension of the beams are 150/250 mm with effective length 1900 mm. All beams were tested using four-point loading to get pure bending in the middle span. The result of the experimental research showed that the ultimate load of the strengthened beams BTF is 49% higher than BT; stiffness of the strengthened beam BTF is 68% higher than BT; and cracking moment of the strengthened beam BTF is 50% higher than BT. However, the deformation and ductility of the strengthened beam BTF is lower than BT 77.6% and 73% respectively. In spite of using laminated CFRP on the concrete beam (BF) may increase the stiffness 33.3% and cracking moment 50%, but using laminated CFRP on the concrete beams as external reinforcement without reinforcing steel bar (BF) is not effective, because the strain of CFRP is only 41% of the maximum strain that may be reached. The failure phenomenon of the concrete beam with laminated CFRP (BTF san BF) is prior de-bonding CFRP that makes maximum performance of the CFRP not be reached