GFRPロッド筋を用いたコンクリートはりの曲げ変形挙動と光ファイバによるヘルスモニタリング

抄録

This study has two major subjects, the use of a new material to the concrete structure, and the application of health monitoring system on the concrete structure. A glass fiber reinforced plastic (GFRP) rod was used for the concrete structure as tension reinforcement. The flexural loading test was carried out for the beam specimens both of GFRP reinforced concrete and conventional reinforced concrete. The health monitoring system which uses an optical fiber as a sensor of crack detection was manufactured by way of trial for this study and was discussed about the availability to detect the cracks. The followings were obtained from this experimental study;
(1) The failure mode of the GFRP reinforced concrete beam was by shear failure combined with bending stress, though the conventional reinforced concrete beam failed in bending mode. The crack initiating load could be calculated precisely for both reinforced concrete beams, but the ultimate shear capacity could not be calculated accurately.
(2) The cracks generated in the GFRP reinforced concrete beam propagated straightly upward even if in shear span, and then the beam suddenly failed by shear after the cracks began to decline obliquely. The developing rate of cracks was not uniform in bending span.
(3) The crack detection system using the optical fiber, was effective to monitor developed cracks, though the flexural behavior was different between the GFRP reinforced concrete beam and the conventional reinforced concrete beam. Therefore, it was indicated that the health monitoring system using the optical fiber might be applied to the concrete beam structure.