为了考察地聚物微观结构与强度的关系,在碱激发剂的作用下制备了硅铝比(结构单元中硅氧四面体与铝氧四面体的个数比)分别为1、1.2、1.5的粉煤灰基地聚物。测试了50°C恒温下养护7d时的抗压强度,并采用SEM、XRF、XRD对地聚物材料进行微观结构测试与分析。结果表明,Si/Al=1的地聚物材料强度最高,在其微观结构中粉煤灰玻璃体被反应层包裹的程度较小,且材料内部无定型物质的反应程度较好。研究揭示了,反应程度偏低是我国粉煤灰基地聚物强度低的主要原因。
In order to study the relationship between mirostructure and strength,geopolymers were prepared by Nantong fly ash under the action of alkali activator withsilica alumina ratio of 1,1.2,1.5.The compressive strength of three kinds of geopolymers which were maintained at 50℃ for seven days was investigated.The three samples were characterized by SEM and XRD to analysize the microscopic characterization.The results showed that the samples with low ratio of silica alumina had better compressive strength.Inside these low silica alumina materials,the vitreous body of fly ash was less wrapped by the reaction layer,and the reaction of amorphous material was better.The study revealed that the low reaction degree was the main reason for geopolymer based on fly ash in China.
[1] Davidovits J.Early high-strength mineral polymer:US,4509985[P].1985-04-09.
[2] 吴小缓,张杨,袁鹏,等.地质聚合物的研究进展与应用[J].硅酸盐通报,2016,35(12):4032-4037.
[3] 孙道胜,王爱国,胡普华.地质聚合物的研究与应用发展前景[J].材料导报,2009,23(4):61-65.
[4] 袁鸿昌,江尧忠.地聚合物材料的发展及其在我国的应用前景[J].硅酸盐通报,1998(2):46-50.
[5] 吴波,房帅,冯玮.采用地聚物粘贴碳纤维布加固混凝土梁试验研究[J].建筑工程学报,2012,33(1):111-118.
[6] 宁松瑞,韩霁昌,张扬,等.粉煤灰在土地整治工程中的研究及应用现状[J].环境工程,2016(S1):1025-1028.
[7] 孟宪娴,韩敏芳,贾屹海,等.粉煤灰基地质聚合物材料性能研究[J].新型建筑材料,2011,37(12):67-70.
[8] He Jian,Zhang Jianhong,Yu Yuzhen,et al.The strength and microstructure of two geopolymers derived from metakaolin and red mud-fly ash admixture:a comparative study[J].Construction and Building Materials,2012,30(5):80-91.
[9] Fletcher R A,MacKenzie K J D,Nicholson C L,et al.The composition range of aluminosilicate geopolymers[J].European Ceram Soc,2005,25(9):1471-1477.
[10] 张书政,龚克成.地聚合物[J].材料科学与工程学报,2003,21(3):430-436.
[11] Kong D L K,Sanjayan J G,Crentsil K S.Comparative performance of geopolymers made with metakaolin and fly ash after exposure to elevated temperature[J].Cem Concr Res,2007,37(12):1583-1589.
[12] 陈瑜,韩汤益,邓怡帆.粉煤灰基地聚合物若干关键问题研究综述[J].硅酸盐通报,2015,34(7):1864-1870.
基金资助
国家自然科学基金项目(51479113)
PDF
(2671KB)
