超高性能纤维粉煤灰混凝土力学特性与微结构影响分析
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（1．广西桂商实业投资有限公司，南宁530200；2．广西路桥工程集团有限公司，）
关键词：超高性能纤维混凝土；粉煤灰；力学性能；耐久性；微观结构；多性能综合指数；性能平衡指数中图分类号：TU528 文献标志码：A 文章编号：1005-8249（2026）01-0068-08DOI:10.19860/j.cnki.issn1005- 8249.2026.01.013
Analysis of the Effect of Fly Ash Content on the Mechanical Properties and Microstructure of Ultra -High- Performance Fiber -Reinforced Concrete
LIANG Hongbin'，XIE Weiwei²(1. Guangxi Guishang Industrial Investment Co.， Ltd.， Nanning 530200， China;2. Guangxi Road and Bridge Engineering Group Co.， Ltd.， Nanning 53OOOO，China)
Abstract:Inorder toexplorethesynergisticefectofflyashcontentonmultiplepropertiesofultra-highperformance fiber concrete， six groups of ratios were designed， including blank group， 10% ， 20% ， 30% ， 40% ，and 50% ，and analyzed through mechanics，durabilityand microscopictestingsystems.Theresultsshowthatthe mechanicalpropertiesareoptimalat 20% of the content，and the 28 - day compressive strength reaches 158.2MPa ，which is 58.2% higher than the UC100 specification limit； the durability reaches the peak at 30% of the content. The chloride ion diffusion coefficient is 1.17×102m2/s the gas permeability coefficient is 6.7×102 ，and the electric flux is 69OC，which are 35.7% ， 31.6% and 42.0% lower than the blank group respectively. Microstructural analysis showed that the peak value of C-S-H content was 1. 15 at 30% doping content，and the total porosity dropped to 9.5% ，which was consistent with the best advantage of macro durability. The multiperformance comprehensive index and the performance balance index are O. 98 and O. 95 respectively at 30% doping content，the fitness index R=0.97 ，and the predicted optimal doping range is 25%～32% ．The research reveals the nonlinear law of "appropriate optimizationand excesive weakening"offlyashcontent on UHPFRC，providing aquantitativebasis for green
design of high-performance concrete.
Key words：ultra-high-performance fiber-reinforced concrete；flyash；mechanical properties；durability；microstructure; multi-performance index；balance index
0 引言
超高性能纤维混凝土（UHPFRC）以极低水胶比、致密基体和高效纤维增韧为特征，兼具超高强度与优异耐久性，广泛应用于桥梁面板、装配式节点及极端荷载防护等结构[1]。（剩余13155字）