PVA纤维增强尾矿砂水泥基复合材料力学性能研究

摘要

[Abstract]A type o f high toughness tailing sand cementitious composite reinforced by PVA fibers was de tailing sand cementitious composite veloped. The compressive strength, flexural strength and breaking resistance of this type of material were studied by uniaxial compressive tests, four-point flexural tests and Impact tests. The results show that the compressive strength is similar to that of concrete but the elastic modulus is lower and the compressive deformation capacity is much higher than that of concrete; It exhibits the characteristics of pseudo strain -hardening, multiple cracking and high ductility as well as high energy absorption, The ultimate strain excesses 2%and the crack width at ultimate load is about 60Lm;the performance of dynamic load resistance is stronger than the ordinary concrete, the ductility index is 8.04, PVA fiber prevents materials open and extension of cracks, and absorbing energy, improve the impact of the material performance, little injury, integrity is strong, energy dissipation power.%研制了采用高强高弹模PVA纤维作为增强材，以特制的尾矿砂水泥砂浆为基体制备PVA尾矿砂水泥基复合材料。本文通过单抗压试验、四点弯曲试验、冲击试验研究这种新型材料的抗压、抗弯和动力荷载作用下的抗裂性能。试验结果表明：该材料抗压强度类似混凝土，弹性模量较低，破坏状态有一定的延性；该材料在弯曲荷载作用下具有假应变硬化和多缝开裂特性,弯曲试验测得的极限拉伸应变在2%以上,极限荷载时薄板试件的最大裂缝宽度在60Lm左右；该材料在动力荷载作用下抵抗动力荷载的性能明显强于普通混凝土，延性指标为8.04，PVA纤维抑制水泥基复合材料裂缝的张开和扩展，并且吸收能量，提高材料的冲击性能，损伤小，整体性强，能量耗散力强。