关键词: 纳米颗粒;道路粉煤灰混凝土;耐磨性能;影响;作用机理

Abstract: In order to investigate the effect of nano-particles on the wer resistance of road concrete containing fly ash,nano-modified fly ash cement mortar specimens were prepared by replacing equivalent cement with nano-materials and ultra-fine fly ash,and on this basis,three types of nano-modified fly ash concrete were prepared,which was nano-SiO2 concrete,nano-SiC concrete and nano double-doped concrete,respectively,afterwords the effects and mechanisms of two types of nano-materials on the mechanical properties of fly ash cement mortar and the wear resistance of road fly ash concrete were studied.The results indicate that the wear resistance of road fly ash concrete is improved significantly when nano-materials are added.The optimum content of nano-SiO2 for single doping NS concrete is 2％,and the optimum content of nano-SiC for single doping NC concrete is 3％;the wear resistance of nano double-doped concrete is the best when the mixing content of NS and NC is 2％ and 2％,respectively,compared with the reference concrete,the wear loss has decreased by 75％.Analysis shows that nano-materials have larger surface energy due to its surface effect,active effect and microscopic aggregate filling effect,the nano-particles react with Ca (OH)2 crystal when the secondary reaction of hydration happen in the cement paste,which has changed the orientation degree of Ca(OH) 2 and strengthened the microstructure in cement paste,has optimized the pore diameter distribution and pore structure of cement matrix,making the slurry more dense,thereby improving the wear resistance of road fly ash concrete.

Key words: nano-particle;road fly ash concrete;wear resistance;effect;mechanism