【摘要】 为了提高煤矸石地聚物混凝土的力学性能，探索其工程应用潜力，以煤矸石、矿渣为原料制备地聚物混凝土，研究纳米SiO₂（0～2.5%）和钢纤维（0～1.25%）单独及复合掺入对地聚物混凝土力学性能的影响，并用扫描电子显微镜观察了地聚物混凝土的微观形貌，分析改性机理。结果表明：适量的钢纤维或纳米SiO₂掺入均能显著提高地聚物混凝土的力学性能，两者混合使用改性效果则更好。在抗压强度方面，纳米SiO₂改性煤矸石混凝土优于钢纤维；在劈裂抗拉和抗折强度方面，钢纤维改性效果更好。纳米SiO₂和钢纤维的复合使用改性效果更好，是由于纳米SiO₂不仅提高了地聚物凝胶的微密度，而且增强了钢纤维与基体之间的结合。研究结果丰富了纳米SiO₂和钢纤维改性地聚物复合材料性能的知识体系，有助于煤矸石地聚物混凝土的进一步推广应用。更多还原

【Abstract】 In order to improve the mechanical properties of coal gangue geopolymer concrete and explore its engineering application potential, geopolymer concrete was prepared with coal gangue and slag as raw materials, and the effects of single addition and mix addition of nano-SiO₂（0～2.5%,mass fraction） and steel fiber（0～1.25 %,volume fraction） on the mechanical properties of geopolymer concrete were studied.Further more, the microstructure of geopolymer concrete was studied by SEM to help analyze the modification mechanism.The results showed that the mechanical properties of geopolymer concrete can be significantly improved by adding appropriate amount of steel fiber or nano-SiO₂,and the effect was better when the two were mixed.In terms of compressive strength, nano-SiO₂ modified effect was better than steel fiber, while in terms of splitting, tensile and flexural strength, steel fiber modification effect was better, presumably due to the different mechanism of action of the two.The combination of nano-SiO₂ and steel fiber has better modification effect because nano-SiO₂ not only improves the micro-density of geopolymer gel, but also enhances the bond between steel fiber and matrix.The research results enrich the knowledge system of the properties of nano-SiO₂ and steel fiber modified geopolymer composites, and guide the further application of coal gangue geopolymer concrete.更多还原