水饱和聚丙烯纤维混凝土的单轴抗压试验研究

Studies on mechanical properties of water-saturated polypropylene fiber concrete

采用液压伺服试验设备对水饱和状态下掺加聚丙烯纤维的混凝土进行单轴压缩试验研究;分析了水饱和条件及聚丙烯纤维掺量对混凝土的抗压强度、弹性模量和应力-应变关系等力学性能的影响;探讨混凝土抗压强度、弹性模量和应力-应变关系与水饱和条件及聚丙烯纤维掺量的变化规律,发现纤维的掺入能有效改善混凝土塑性,当纤维掺量为2 kg/m3时这种现象尤其显著,水饱和条件导致混凝土塑性变形能力下降,在相同的应力水平下,水饱和混凝土的开裂应力明显低于干燥混凝土的开裂应力,并通过对应力-应变曲线归一化处理,建立了聚丙烯纤维混凝土在干燥与水饱和条件下的应力应变本构关系表达式。

The uniaxial compression tests of water-saturated polypropylene fiber concrete has been conducted by using a servo-hydraulic testing system.The influence of water saturated condition and the amount of polypropylene fibers on mechanical properties of concrete, such as concrete compressive strength, modulus of elasticity and the stress-strain relation have been studied.The mechanism of concrete compressive strength, modulus of elasticity and the stress-strain relation affected by different amount of polypropylene or water-saturated condition have been analyzed, the regular pattern have been found that the plastic of concrete could be improved with the incorporation of the fibers, particularly when the amount of fiber was 2 kg/m3.The concrete plastic declines when under the water-saturated condition.At the same stress level, the cracking stress of water-saturated concrete was significantly lower than the dry concrete.By the normalized process- ing of stress-strain curve, the stress-strain relation expression of polypropylene fiber concrete in drying or water saturated states have been established.