摘要
为了考察混凝土建筑在酸雨环境腐蚀下的耐久性问题,研究不同配合比的混凝土材料在酸雨侵蚀作用下的抗压强度、抗折强度和抗冲击性等性能,通过X射线衍射(XRD)、压汞测孔法(MIP)、扫描电镜和能谱仪(SEM-EDS)等测试方法,从粉煤灰、膨胀剂、聚丙烯纤维的作用机理入手,研究了侵蚀前后混凝土试块中水化产物微观结构及内部孔结构特征的变化。结果表明,聚丙烯纤维粉煤灰膨胀混凝土的抗酸雨腐蚀性效果最佳。基准混凝土水化产物在酸雨介质侵蚀下易转换为石膏和SiO2.nH2O,而聚丙烯纤维粉煤灰膨胀混凝土结构致密,有害孔显著减少,可有效阻碍酸雨介质侵蚀作用。
In order to evaluate the durability of concrete constructions exposed to acid rain, such properties of concrete corroded by acid rain are investigated here as compressive strength, flexural strength and resistance to impact. By means of X ray diffraction （XRD） , mercury intrusion poremea- surement（ MIP）, scanning electron microscope （ SEM ） and energy dispersive spectrometer （ EDS ）, mechanism of fly ash, expansive agent and polypropylene fiber are investigated. Microstructure and porosity characteristics of hydrated products before and after corrosion are also examined. The results indicate that the polypropylene fiber reinforced concrete incorporated with fly ash and expansion agent exhibit better anti acid rain corrosion performance than other mixes. The hydration products of the reference sample are easily converted to gypsum and SlO2·nH2 0 under the action of acid rain.Microstructure of concrete adding admixture is denser so as to effectively prevent concrete damage induced by acid rain.
出处
《南京理工大学学报》
EI
CAS
CSCD
北大核心
2012年第4期717-723,共7页
Journal of Nanjing University of Science and Technology
基金
国家自然科学基金(51178221)
国家住建部科学技术项目(2011-K4-24)
关键词
酸雨
聚丙烯纤维
孔结构
水化产物
acid rain
polypropylene fibers
pore structures
hydration products
