EXPERIMENTAL STUDY OF FLEXURAL BEHAVIOR OF DUCTILE FIBER REINFORCED CONCRETE

To study the effects of fiber content，water-binder ratio，sand-binder ratio，and fly-ash content，16 groups of ductile high performance concrete specimens were designed for the orthogonal test，whose flexural performance was tested through the four-point bending test． The analysis of first-crack strength，ultimate flexural strength，equivalent flexural strength，and toughness indexes of 16 groups specimens indicated that the fiber content changed the concrete failure mode and greatly improved the concrete bending strength and flexural toughness． The fiber content greatly influenced the flexural behavior，the more fiber content，the higher the bending strength，and toughness． The effects of water-binder ratio，sand-binder ratio，and fly-ash content on the flexural performance were smaller，and the effect of fly-ash content on them was the smallest． When the water-binder ratio was higher than 0. 29，sand-binder ratio was less than 0. 36，the ductile fiber reinforced concrete in the experiment showed a high flexural toughness．