季冻区纳米SiO_(2)改性SAP路面混凝土的耐磨性

Abrasion Resistance of Modified SAP-Pavement-Concrete by Nano-SiO_(2)in Seasonal Frozen Area

为解决季冻区高吸水性树脂(SAP)路面混凝土耐磨性下降的问题,通过耐磨性试验探索了纳米SiO_(2)(NS)对季冻区SAP路面混凝土磨损量的影响;采用压汞仪(MIP)和扫描电镜(SEM)研究了冻融前后NS改性SAP路面混凝土孔结构和微观形貌的变化,从细微观角度阐述其耐磨性的提升机理;并对其微观结构与耐磨性进行相关性分析。研究结果表明,经150次冻融循环之后,掺有3%NS的改性SAP路面混凝土在200 N磨耗负荷下的磨损量较基准下降30.92%,20~50nm的孔占比上升,50~200nm的孔占比下降,总孔隙量和孔隙率减少,界面区裂缝数量和尺寸大幅降低,内部密实性程度显著提高,耐磨性明显增强。

In order to solve the problem of the decrease in abrasion resistance of SAP-pavement-concrete in seasonal frozen area,the effect of nano-SiO_(2)(NS)on the abrasion of SAP-pavement-concrete in seasonal frozen area was explored by abrasion resistance test.The pore structure and micromorphology variations of modified SAP-pavement-concrete by NS before and after freeze-thaw were analyzed by mercury intrusion pressure(MIP)and scanning electron microscopy(SEM).The enhancement mechanism of abrasion resistance was revealed from microscopic level.The relationship between pore size distribution and pore parameters with abrasion resistance were analyzed.The results show that after 150 freeze-thawing cycles,the abrasion amount of concrete modified by 3%NS decreases by 30.92%compared with JZ under 200 N load.Concurrently,there was an increase in the proportion of pores at the 20—50 nm,while the proportion of pores at 50—200 nm decreased.Additionally,total pore volume and porosity diminished,accompanied by a significant reduction in the number and size of interface cracks.Internal structure density was increased significantly,and the wear resistance was enhanced significantly.