Mechanical Properties of Composite Materials with High Strength Steel(780N/mm2)and CFRP Plate

The new high-strength steel (tensile strength is 780N/mm ) for steel buildings was developed by a Japanese company. The stronger the steel material becomes, the lighter form of steel structure can be made. Essentially steel structure has the problem of lack of stiffness in entire structure. The weak point of high-strength steel may be overcome in the near future because stronger steel is being developed. To solve the difficulty, we propose the high-strength steel composite member with high-stiffness materials in this study. High-stiffness carbon-fiberreinforced-plastic (CFRP) plate has 296kN/mm2 in its Young's Modulus which is greater than steel one. Although we reported the effectiveness of the normal steel composite member with CFRP plate, there is no data of composite member in combination with high-strength steel and CFRP plate such as structural performance, bond strength, etc. In this paper, we report the data from elementary tests such as tensile tests, bending tests, bond strength tests on composite members to show the possibility of the composite member made of CFRP plate and high-strength steel.