位置:首页 >> 正文
作者:李华1 孙伟1 左晓宝1 2 
单位:1. 东南大学材料科学与工程学院 江苏省土木工程材料重点实验室 南京 211189  
关键词:矿物掺合料 水泥基材料 硫酸钠侵蚀 微结构 微观测试方法 

  要:采用CTX射线衍射、扫描电子显微镜等测试方法,通过对不掺矿物掺合料以及掺30%粉煤灰或50%矿渣的水泥净浆、水泥砂浆在室温下5% Na2SO4溶液中浸泡2 a后的宏观破坏形态和浆体组分及浆体形貌的分析,从微观层次上研究了矿物掺合料对水泥基材料抗硫酸盐侵蚀破坏的影响。结果表明:侵蚀后不掺矿物掺合料的试件由表及里呈现三层不同侵蚀状态,即表层石膏区、中层钙矾石区以及内层未侵蚀区。矿物掺合料的C3A含量稀释效应、火山灰反应以及微集料填充效应协同作用的结果使得试件的抗硫酸钠溶液侵蚀破坏性能显著提高。但矿渣中活性Al3+含量较高,能与SO42反应生成大量钙矾石晶体,掺量不当会对试件的抗硫酸钠侵蚀性能不利。砂集料有阻碍微裂纹发展及增大试样内部不均匀性的相反作用,集料的含量、颗粒尺寸及分布对水泥基材料的抗硫酸钠侵蚀破坏性能的影响是以后研究中需关注的问题。

women want men how to cheat how do i know if my wife cheated
open open My husband cheated on me
abortion las vegas period after abortion abortion pictures
bystolic copay card bystolic coupon voucher

Abstract: The appearance observation, mineral composition, as well as microstructure morphology towards various cement pastes and motars with and without 30% fly ash or 50% slag dipped in 5% Na2SO4 solution at room temperature for 2 years were characterized by X-CT, X-ray diffraction and scanning electron microscopy to investigate the effects of mineral admixtures such as slag and fly ash on the sulfate resistance performance of cement-based materials from the micro-level angle. The results show that the specimens without mineral admixtures appear three different attack states from surface to inside, i.e., the gypsum area, the ettringite area and the unaffected area. Mineral admixtures can improve the sulfate resistance performance of cement-based materials via synergy effect of reducing C3A content, pozzolanic reaction and micro-aggregates filling. However, the improper content of slag in cement-based materials has a negative effect on the sulfate resistance performance as active Al3+ reacts with SO42 to form massive ettringite. The sand aggregates can hinder the development of micro-cracks and increase the internal heterogeneity of the specimens. It is revealed that the content, particle size and distribution of aggregate all have effects on the sulfate resistant performance of cement-based materials, which should be a further research aspect.

redirect husband cheated unfaithful husband
my wife cheated on me now what i dream my husband cheated on me husband cheat
第一作者:李 华(1987—),女,硕士研究生。 通信作者:孙 伟(1935—),女,教授。
online women that cheat with married men married woman looking to cheat
open cheat women go
how to catch a cheater redirect go
bystolic copay card bystolic coupon voucher

[1]  余红发. 盐湖地区高性能混凝土的耐久性、机理与使用寿命预测方法[D]. 南京: 东南大学, 2004.

YU Hongfa. Study on high performance concrete in salt lake: durability, mechanism and service life prediction (in Chinese, dissertation). Nanjing: Southeast University, 2004.

[2]  高礼雄. 掺矿物掺合料水泥基材料的抗硫酸盐侵蚀性研究[D]. 北京: 中国建筑材料科学研究院, 2005.

GAO Lixiong. Study on resistance to sulfate attack on cement based composite material containing mineral additive (in Chinese, dissertation). Beijing: China Building Materials Aeademy, 2005.

[3]  ROY D M, ARJUNAN P, SILSBEE M R. Effect of silica fume, metakaolin and low-calcium fly ash on chemical resistance of concrete [J]. Cem Concr Res, 2001, 31(12): 18091813.

[4]  牛全林, 张勇. 矿物质混合材对水泥砂浆抗硫酸盐腐蚀的影响[J]. 硅酸盐学报, 2006, 34(1): 114117.

NIU Quanlin, ZHANG Yong. J Chin Ceram Soc, 2006, 34(1): 114117.

[5]  ESHMAIEL G, HOMAYOON S P. Effect of magnesium and sulfate ions on durability of silica fume blended mixes exposed to the seawater tidal zone [J]. Cem Concr Res, 2005, 35(7): 1332–1343.

[6]  NOBST P, STARK J. Investigations on the influence of cement type on thaumasite formation [J]. Cem Concr Compos, 2003, 25(8): 899–906.

[7]  LU S, LANDIS E N, KEANE D T. X-ray microtomographic studies of pore structure and permeability in Portland cement concrete [J]. Mater Struct, 2006, 39(6): 611–620.

[8]  STOCK S R, NAIK N N, WILKINSON A P, et al. X-ray micro- tomography (microCT) of the progression of sulfate attack of cement paste [J]. Cem Concr Res, 2002, 32(10): 16731675.

[9]  BURLION N, BERNARD D, CHEN D. X-ray microtomography: Application to microstructure analysis of a cementitious material during leaching process [J]. Cem Concr Res, 2006, 36(2): 346–357.

[10]  朱红光, 谢和平, 易成, . 岩石材料微裂隙演化的CT识别[J]. 岩石力学与工程学报, 2011, 30(6): 12301238.

ZHU Hongguang, XIE Heping, YI Cheng, et al. CT identification of microcracks evolution for rock materials [J]. Chin J Rock Mech Eng, 2011, 30(6): 12301238.

[11]  MINDESS S, YOUNG J F, DARWIN D. 吴科如等译. 混凝土 (第二版). 北京: 化学工业出版社, 2005: 426430.

MINDESS S, YOUNG J F, DARWIN D. WU Keru, et al (translate), Concrete (2nd ed). Beijing:Chemical Industry Press, 2005: 426–430.

[12]  TIXIER R, MOBASHER B. Modeling of damage in cement-based materials subjected to external sulfate attack. II: comparison with experiments [J]. J Mater Civ Eng, 2003, 15(4): 314322.

[13]  SANTHANAM M, COHEN M D, OLEK J. Mechanism of sulfate attack: A fresh look: Part 1. Summary of experimental results [J]. Cem Concr Res, 2002, 32(6): 915–921.

[14]  SANTHANAM M, COHEN M D, OLEK J. Mechanism of sulfate attack: a fresh look: Part 2. Proposed mechanisms [J]. Cem Concr Res, 2003, 33(3): 341346.


women want men signs of unfaithful husband how do i know if my wife cheated
abortion las vegas abortion pill online abortion pictures
京公网安备 11010802024188号
地址:北京市海淀区三里河路11号    邮政编码:100831
电话:010-57811253  57811254