为了获得腐蚀介质对水泥浆体溶蚀特性的影响规律,采用去离子水和6 M NH_4Cl溶液作为腐蚀介质,分别开展室温(25℃)环境下水灰比为0.45的硬化水泥净浆薄片试件的常规和加速溶蚀,并通过饱水干燥称重法、扫描电子显微镜(SEM/EDS)、X射线衍射...为了获得腐蚀介质对水泥浆体溶蚀特性的影响规律,采用去离子水和6 M NH_4Cl溶液作为腐蚀介质,分别开展室温(25℃)环境下水灰比为0.45的硬化水泥净浆薄片试件的常规和加速溶蚀,并通过饱水干燥称重法、扫描电子显微镜(SEM/EDS)、X射线衍射法(XRD)等测试,分析了2种腐蚀介质中硬化水泥浆体的孔隙率、钙硅比及其物相组成和微结构的演变规律。结果表明,在25℃室温环境下,同去离子水相比,氯化铵溶液中水泥净浆试件孔隙率增加和钙硅比降低的速率均显著提高,而氯化铵溶液中溶蚀9 d后的试件微观形貌与去离子水浸泡360 d的微结构形貌基本一致,且溶蚀后的物相组成也基本相同;氯化铵溶液显著提高了硬化水泥浆体的溶蚀进程,并可较短的时间内获得其溶蚀特性,但并未改变溶蚀过程中硬化水泥浆体的物相组成和微结构特性,可作为混凝土等水泥基材料的加速溶蚀介质。展开更多
The heterogeneous nucleation behaviors of NHaCI crystal on a rough chilling surface of aluminum immerged in NHaCI-H20 solution were experimentally analyzed and the relationship between the surface roughness and the nu...The heterogeneous nucleation behaviors of NHaCI crystal on a rough chilling surface of aluminum immerged in NHaCI-H20 solution were experimentally analyzed and the relationship between the surface roughness and the nucleation site selection behaviors on polished aluminum substrate was investigated, and it was discovered that the number of nucleation sites decreases significantly with decreasing the roughness of the polished substrate. Further nucleation experiments were carried out on chemically etched aluminum substrate with regular micro- morphology on its surface. It has been shown that both the micro-morphology and the wettability vary with the substrate surface prepared by different etching process. The prepared surface with step-like structures has a strong wettability with NH4CI-70 wt% H20 solution and the nucleation density of NH4CI on the its surfaces is significantly higher than that of the reference surfaces, which shows that the geometrical morphology features have important effects on both the wettability and the nucleation behaviors.展开更多
文摘为了获得腐蚀介质对水泥浆体溶蚀特性的影响规律,采用去离子水和6 M NH_4Cl溶液作为腐蚀介质,分别开展室温(25℃)环境下水灰比为0.45的硬化水泥净浆薄片试件的常规和加速溶蚀,并通过饱水干燥称重法、扫描电子显微镜(SEM/EDS)、X射线衍射法(XRD)等测试,分析了2种腐蚀介质中硬化水泥浆体的孔隙率、钙硅比及其物相组成和微结构的演变规律。结果表明,在25℃室温环境下,同去离子水相比,氯化铵溶液中水泥净浆试件孔隙率增加和钙硅比降低的速率均显著提高,而氯化铵溶液中溶蚀9 d后的试件微观形貌与去离子水浸泡360 d的微结构形貌基本一致,且溶蚀后的物相组成也基本相同;氯化铵溶液显著提高了硬化水泥浆体的溶蚀进程,并可较短的时间内获得其溶蚀特性,但并未改变溶蚀过程中硬化水泥浆体的物相组成和微结构特性,可作为混凝土等水泥基材料的加速溶蚀介质。
基金supported by the National Natural Science Foundation of China (No. 50901061 and 50971102)the National Key Basic Research Project of China (No. 2011CB610402)the research fund of the State Key Laboratory of Solidification Processing (NWPU), China(Grant No. 02-TZ-2008, 36-TP-2009)
文摘The heterogeneous nucleation behaviors of NHaCI crystal on a rough chilling surface of aluminum immerged in NHaCI-H20 solution were experimentally analyzed and the relationship between the surface roughness and the nucleation site selection behaviors on polished aluminum substrate was investigated, and it was discovered that the number of nucleation sites decreases significantly with decreasing the roughness of the polished substrate. Further nucleation experiments were carried out on chemically etched aluminum substrate with regular micro- morphology on its surface. It has been shown that both the micro-morphology and the wettability vary with the substrate surface prepared by different etching process. The prepared surface with step-like structures has a strong wettability with NH4CI-70 wt% H20 solution and the nucleation density of NH4CI on the its surfaces is significantly higher than that of the reference surfaces, which shows that the geometrical morphology features have important effects on both the wettability and the nucleation behaviors.
