聚丙烯纤维高性能混凝土用于海洋浪溅区的研究与应用  

Research and Application of Polypropylene Fiber Reinforced High Performance Concrete in Marine Tidal Zone

作　　者：刘竞[1] 邓德华[1] 黄波[1] 刘新林 

机构地区：[1]中南大学,湖南长沙410075 [2]中国铁建十二局,山西太原030900

出　　处：《施工技术》2008年第4期93-96,99,共5页Construction Technology

基　　金：铁道部科技司项目"铁路客运专线高性能混凝土施工技术研究";中南大学研究生创新基金项目(053720010)

摘　　要：将聚丙烯纤维高性能混凝土用于浪溅与水位变动区。通过抗压强度、Cl-渗透、平板抗裂、冻融循环以及加速腐蚀的护筋性试验发现:加纤维与硅灰的混凝土强度明显高于单掺纤维或粉煤灰,抗渗性显著提高;经300次冻融循环,动弹性模量下降率和质量损失率分别为8.7%、1.84%;钢筋加速腐蚀电位明显高于同期其他钢筋。加入纤维对抑制早期开裂效果显著,降低浇筑振捣不当及材料沉降对混凝土匀质性的不利影响。单掺纤维未对强度和抗Cl-渗透有显著改善,加入硅灰增加纤维的有效性。加纤维与硅灰的混凝土性能显著改善是纤维阻裂和硅灰对纤维-基体、骨料-浆体界面过渡区增强的复合作用。Polypropylene fibers reinforced high performance concrete was used in tidal zone tentatively. By experiments including compressive strength, chloride diffusion, anti-cracking test, freezing-thawing cycles and rapid corrosion potential of steel bar test, results showed the incorporation of polypropylene fibers and silica fume increased compressive strength obviously, and caused a significant increase of chloride permeability. Relative dynamic modulus and mass loss of concrete after 300 freezing-thawing cycles in simulative sea water were 8.7%, 1.84% respectively. Its corrosion potential of steel bar was higher than others in corresponding period. The incorporation of fibers improved the performance of anti-cracking at early age significantly, reduced the adverse influence of improper placement or consolidation and materials sedimentation on concrete homogeneity. Just incorporating fiber had no obvious improvement on strength and impermeability, however, the addition of silica fume was noted to significantly enhance the polypropylene fibers effectiveness. Therefore the significant improvement on concrete properties resulted from both the anti-cracking effect of polypropylene fibers and reinforcement action to the interfacial transition zone of fiber-matrix and aggregate-cement paste by silica fume.

关 键 词：高性能混凝土 聚丙烯纤维 氯离子渗透 抗裂性 冻融循环 浪溅区 

分 类 号：TU528.36[建筑科学—建筑技术科学]