UNI-AXIAL AND BENDING TESTS ON HYBRID FIBRE REINFORCED CONCRETE

Based on the idea to take simultaneous advantage of the effects of different types of fibres, new materials called Hybrid FRCs have been developed by combining fibres of different geometry and material. In the present paper, the benefits in terms of concrete toughness from a combination of micro and macro steel-fibers are evaluated under both uniaxial and bending tests on specimens of different sizes. Freely rotating platens made with spherical hinges and an appropriate apparatus for centering the specimen on the platens were adopted in the uni-axial tensile tests. Experimental results are highly sensitive to the strain gradient in the cracked section, to the fibre geometry and to the area of the cracked surface. In fact, a larger scatter in the experimental results was observed in specimens with smaller cracked surfaces where a larger scatter of the macro-fibre density was present. For this reason, beside the size effects, the dimension of the cracked section markedly influenced the characteristic value of the fracture parameters. Hybrid combination of short and long steel fibres can improve concrete toughness for both small and large crack opening displacement.

• INTRODUCTION

• MATERIALS

• EXPERIMENTAL SET-UP

• EXPERIMENTAL RESULTS

• CONCLUDING REMARKS

• ACKNOWLEDGMENTS

• REFERENCES