聚乙烯纤维增强赤泥-碱矿渣复合材料的力学性能

Mechanical properties of polyethylene fiber reinforced red mud-alkali slag composite

为开发赤泥(RM)的资源化利用,采用RM混合矿渣与硅灰并掺加聚乙烯纤维制备中高强、高延性碱激发复合材料,研究其单轴拉伸及抗压性能,结合三点抗弯与单裂缝拉伸等细观试验探究材料的高延性机制,并通过XRD及FTIR分析水化产物。结果表明:聚乙烯纤维增强赤泥-碱矿渣复合材料的抗拉强度可以达到2.4 MPa,同时拥有3.5%的高拉伸应变性能;抗压强度可以达到近50 MPa的较高水平;细观试验得出的较大应变硬化性能指数PSH对应较高拉伸应变;除水化硅酸钙(C-S-H)或水化硅铝酸钙(C-A-S-H)凝胶外,水化产物中还包含碱性硅铝酸盐(N-A-S-H)凝胶。

To develop the resource utilization of red mud(RM),RM mixed with slag and silica fume along with addition of polyethylene fibers was used to prepare moderate-to-high strength and high ductile alkali-activated composite,and the macroscopic uniaxial tensile and compressive properties were investigated.The mechanisms of high ductility were explored by meso-scale experiments including three-point bending and single crack tensile tests.Meanwhile,the products of hydration reaction were analyzed through microscopic characterizing.The results show that the tensile strength of the studied material could be up to 2.4 MPa,along with a relatively high tensile strain capacity of 3.5%.The compressive strength could reach around 50 MPa.The larger pseudo strainhardening PSH indices obtained by meso-scale tests correspond to the higher tensile strain.Apart from calcium silicate hydrate(C-S-H)or calcium aluminosilicate hydrate(C-A-S-H)gels,the hydration products also contain alkaline aluminosilicate(N-A-S-H)gel.