延性纤维混凝土抗弯性能的试验研究

采用正交试验方法,考虑纤维掺量、水胶比、砂胶比和粉煤灰掺量的影响,设计了16组延性纤维混凝土试件,采用四点弯曲试验评定其抗弯性能。通过对弯曲初裂强度、极限抗弯强度、等效弯曲强度和弯曲韧性指数的分析可得:纤维的掺入改变了试件的破坏模式,显著提高了材料的抗弯强度和弯曲韧性;纤维掺量对抗弯性能影响显著,纤维掺量越大,抗弯强度和弯曲韧性越高;水胶比和砂胶比的影响次之,粉煤灰掺量的影响最小,水胶比不低于0.29,砂胶比不超过0.36时,延性纤维混凝土均具有较高的弯曲韧性。

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.