HPFRCC常规三轴受压强度和变形特性

摘要

通过常规三轴受压强度和变形特性试验,研究了围压以及PVA纤维掺量对高性能PVA纤维增强水泥基复合材料(HPFRCC)受压性能的影响.结果表明:随着围压的增加,HPFRCC的轴向极限抗压强度以及峰值应变均显著提高;PVA纤维掺量对HPFRCC抗压强度的影响较小,在低围压受力状态下使用PVA纤维增强HPFRCC要比在高围压受力状态下更能发挥纤维的增强阻裂作用,而且PVA纤维掺量对应力-应变曲线下降段也有一定影响.根据试验数据建立了HPFRCC的轴向极限抗压强度、轴向峰值应变与围压之间的关系.%Based on experiments for strength and deformation under conventional triaxial compression, the influences of confining pressure and PVA fiber content by volume on compressive performance of high performance fiber reinforced cement composite(HPFRCC) were studied. Study results indicate that ultimate strength and peak strain were significantly improved as the confining pressure increased. Because confining pressure is the significant factor, the confining effect introduced by PVA fiber content by volume is minor. PVA fiber played main role for the strength under the lower confining pressure. The axial stress-strain curves with different confining pressure and different PVA fiber content by volume are obtained. Lateral confining pressure constraints the lateral expansion of HPFRCC, so there is a big deformation capacity with its ultimate strength improved. At lower confining pressure, PVA fiber content by volume has some effect on the decreased section of stress-strain curve. According to test results, the relation among confining pressure, ultimate strength and axial peak strain is established.