中文摘要：

对掺聚丙烯腈纤维、钢纤维和混杂纤维自密实混凝土的配制进行了系列试验,得到纤维自密实混凝土的配制方法及纤维的适宜掺量。试验结果表明,当聚丙烯腈纤维掺量不高于1.2 kg/m3、钢纤维体积掺量不高于1.5%的情况下,通过适当调整外加剂的掺量、类型以及砂率,可以使混凝土达到自密实的工作性能。纤维自密实混凝土的28 d立方体抗压强度、劈拉强度试验表明,聚丙烯腈纤维掺量对自密实混凝土抗压强度的影响较小,劈拉强度随掺量增大而提高,但当掺量达到1.2 kg/m3时,将导致其劈拉强度的降低,因此聚丙烯腈纤维的掺量宜控制在0.9 kg/m3时为佳;钢纤维体积率变化对自密实混凝土劈拉强度的增强效果明显,混杂纤维的掺入对自密实混凝土抗压强度的影响较小,但对劈拉强度有一定影响,即掺量越大,劈拉强度越高。纤维自密实混凝土早期抗裂性能试验结果表明,在自密实混凝土中掺入纤维,将有助于早期抗裂性能的提高。

英文摘要：

The mix design method of polyacrylonitrile fiber,steel fiber and hybrid fiber reinforced self-compacting concrete（SCC） was studied through a serial of experiments,and the appropriate amount of fiber used in the method was obtained.It can be concluded that,when the dosage of polyacrylonitrile is not higher than 1.2 kg/m3 or the volume fraction of steel fiber is not more than 1.5%,a fine workability of the fiber reinforced SCC（FRSCC） can be obtained by an appropriate adjustment of the sand-aggregate ratio,dosage and type of fiber.From the cube compressive strength and splitting tensile strength at 28 days and the early age cracking behaviors obtained by FRSCC test,the following conclusion can be drawn.The effect of polyacrylonitrile fiber on the compressive strength of FRSCC is limited.The splitting tensile strength of FRSCC enhances with the increase in the dosage of polyacrylonitrile fiber.However,when the dosage of polyacrylonitrile fiber reaches 1.2 kg/m3,it leads to reduction in splitting tensile strength of FRSCC.Therefore,polyacrylonitrile fiber dosage should be controlled at about 0.9 kg/m3.The splitting tensile strength of FRSCC obviously enhances with the increase in the steel fiber volume fraction.The influence of hybrid fiber on the compressive strength of FRSCC is low.The splitting tensile strength of FRSCC enhances with the hybrid fiber dosage increasing.The SCC mixed with fiber may contribute to its crack resistance in the early age.