Experimental and numerical analysis of flexural concrete-UHPFRC/RC composite members

Abstract

This paper presents experimental and numerical analysis of newly cast flexural concrete-UHPFRC/RC beams. In total, 4 intermediate-scale composite beams were cast and tested using 4-point bending test setup. Midspan deflection, curvature and reinforcement strains were measured during experimental program. Clear efficiency of composite beams was observed in comparison to RC beams: Enhanced flexural capacity, increased stiffness, reduced crack widths and spacing, and reduced reinforcement tensile stress. All experimental results were compared with numerical calculations. Analysis of variety of tensile strength of UHPFRC showed significant influence on the results of composite beams. As well as, using post-failure tensile stress-displacement or tensile stress-fracture energy relations, it is not possible to evaluate strain-hardening effect of tensile UHPFRC, and the material model has to be simplified. However, experimental and numerical results were in sufficiently good agreement.