纤维增强混凝土局部抗压性能试验

基于斜向预应力混凝土道面锚固区应力复杂、混凝土抗裂性能差的特点,开展了纤维混凝土试件局部抗压性能试验,得到了纤维混凝土试件在局部荷载作用下的典型破坏模式,分析了支撑状态、纤维掺量对开裂强度和极限抗压强度的影响,揭示了纤维混凝土在局部受压条件下的破坏机理,并基于拉-压杆模型得到了带孔纤维增强混凝土局部受压承载力提高系数.结果表明试件支撑状态和纤维掺量均显著影响局部抗压承载力和破坏模式;对于相同的支撑状态,随着纤维掺量的增大,试件局部抗压能力逐渐增大;对于相同的纤维掺量,底部完全支撑时试件局部抗压承载力显著高于底部部分支撑状态下的承载力;局部受压面积比、预留孔道尺寸显著影响纤维混凝土试件的局部承载力提高系数.

Research on Local Compressive Properties of Steel Fiber Reinforced Concrete

In view of the characteristics of complex stress and high tensile stress in anchorage zone of cross tensioned prestress concrete pavement, the experimental study on local compressive performance of fiber reinforced concrete is carried out, and the typical failure mode of fiber reinforced concrete under local compressive load is obtained. Furthermore, the influence of the supporting conditions and fiber content on the cracked and ultimate strength is analyzed. The failure mechanism of fiber reinforced concrete under local compressive load is revealed. Additionally, the enhancement coefficient of local compressive bearing capacity of fiber reinforced concrete with ducts is obtained based on the pull rod model. The results show that the supporting conditions and fiber content of fiber reinforced concrete have significantly influence on its local compressive bearing capacity and failure mode. The local compressive bearing capacity of fiber reinforced concrete increases gradually with the increase of fiber content for the same support condition. The local compressive bearing capacity of the fiber reinforced concrete under full supporting condition is significantly higher than that under partial supporting condition for the same fiber content. The ratio of local compressive area and the size of reserved ducts significantly influence the enhancement coefficient of local bearing capacity.