Author(s)

Jae Yoon Kang^*, Jong Sup Park, Woo Tai Jung, Moon Seoung Keum

Structural Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology, Goyang, Republic of Korea.

As part of a research intending to develop steel-concrete hybrid girder using ultra high performance concrete with compressive strength of 80 MPa, this study conducts loading test on this girder to investigate the methods for its composition with a slab using 30 MPa-concrete and the corresponding interfacial behavior. Prior to the loading test, the design formula of the Eurocode for the shear resistance developed in concrete-to-concrete interface is examined for the interface between concrete layers of different strengths. The effect of the surface roughness on the shear resistance is examined using this formula and finite element analysis to verify the applicability of the formula. Based upon the results, loading test is conducted on girder specimens to evaluate the actual behavior with respect to the interfacial surface condition. The test results reveal that the specimen with rough interface could not develop perfectly composite behavior and experienced adhesive failure. In case of simultaneous action of flexure and shear, it appears that conservative design should be applied without consideration of the interfacial condition when determining the arrangement of shear reinforcement.

Shear Resistance, Interface between Concrete Layers, Surface Roughness, Steel-Concrete Hybrid Girder, Ultra High Performance Concrete (UHPC)

Kang, J. , Park, J. , Jung, W. and Keum, M. (2015) Connection between Concrete Layers with Different Strengths. Engineering, 7, 365-372. doi: 10.4236/eng.2015.77032.