材料期刊网

针对项目组研发的高性能环保型建材即替代比率达50％的尾矿砂PVA纤维水泥基复合材料，采用立方体抗压实验、薄板四点弯曲实验和薄板拉伸实验，分别测得了该复合材料的抗压强度、弯曲荷载-挠度位移和拉伸应力-应变等特性曲线，获得了该复合材料的弯曲韧性和弯曲强度以及断裂能和抗拉强度。通过实验，研究PVA纤维掺量和水胶比等因素对尾矿砂PVA纤维水泥基复合材料增强和增韧性能的影响。实验结果表明，配合比对尾矿砂PVA纤维增韧水泥基复合材料的力学性能有显著影响；合适的配合比可使该复合材料获得准应变硬化和多裂缝特征，使其具有良好的弯曲韧性和抗拉延性以及较好的抗压强度、弯曲强度和抗拉强度。综合评价了尾矿砂PVA纤维增强水泥基复合材料的强度、韧性及其适用性，为该环保型复合材料的工程应用提供了依据。

The toughening properties of the PVA fiber tailings cementitious composites developed by the proj ect team were studied based on the cube resisting compression test,the four-point bending test of thin plates and the tensile test of thin sheets.The composite is a kind of high performance building material with environmental protection characteristics,the replacement ratio of natural sand with tailings of wicth is 50%.The characteristic curves of bending load-deflection and tensile stress-strain and compressive strength of were tested,and the flex-ural toughness,the bending strength,the fracture energy and the tensile strength of the composites were ob-tained.The effect of the fiber content and water-binder ratio on reinforcing and toughening properties of the PVA fiber reinforced tailings cementitious composites was studied by experiments.The results showed that the composite mix proportion has significant effect on the mechanical properties of the PVA fiber reinforced tailings cementitious composites;the composite materials with appropriate mix proportion would present pseudo-strain-hardening and multi-crack characteristics and have excellent flexural toughness,tensile ductility and better com-pressive,bending and tensile strength.This paper comprehensively evaluated the strength,toughness and ap-plicability of the PVA fiber reinforced tailings cementitious composites,and provided the basis for the engineer-ing application of the environmental protection composite material.