碳纤维改性粉煤灰-偏高岭土地聚合物混凝土的力学性能研究

Study on Mechanical Properties of Carbon Fiber Modified Fly Ash-metakaolin Geopolymer Concrete

【目的】地聚合物混凝土由于强度高、耐久性好、低碳环保等优点受到了广泛关注,然而抗裂性差、韧性差等缺陷制约了其应用。【方法】将10组不同体积掺量的碳纤维掺入粉煤灰-偏高岭土地聚合物混凝土中,分析碳纤维体积掺量对地聚合物混凝土轴心抗压强度、弹性模量、抗折强度及折压比的影响。【结论】结果表明,掺入碳纤维可同时对地聚合物混凝土产生增强、增韧的效应;随着碳纤维掺量的增加,地聚合物混凝土轴心抗压强度、弹性模量、抗折强度及折压比均呈先增加后减小的变化趋势,最优碳纤维掺量为0.8%~1.0%;碳纤维对地聚合物混凝土抗折强度的提升效能约优于抗压强度的2倍。为碳纤维改性地聚合物混凝土的工程应用提供进一步的参考。

【Purposes】Geopolymer concrete has attracted wide attention because of its high strength,good durability,low carbon,and environmental protection,but its application is restricted by the poor crack resistance and toughness.【Method】In this study,10 groups of carbon fibers with varying volume contents were mixed into fly ash-metakaolin geopolymer concrete,and the effects of carbon fiber volume contents on axial compressive strength,elastic modulus,flexural strength,and the folding-compression ratio of geopolymer concrete were analyzed.【Conclusions】The results show that adding carbon fiber could strengthen and toughen geopolymer concrete at the same time.With the increase in carbon fiber content,the axial compressive strength,elastic modulus,flexural strength,and folding-compression ratio of geopolymer concrete all increased at first and then decreased,and the optimum carbon fiber content was 0.8%~1.0%.The improvement effect of carbon fiber on the flexural strength of geopolymer concrete was about twice that of the compressive strength.Further reference is provided for the engineering application of carbon fiber modified geopolymer concrete.