冻融与侵蚀作用下引气混凝土劣化微观机理

耿娇; 刁波; 陈圣刚

冻融与侵蚀作用下引气混凝土劣化微观机理

北京航空航天大学交通科学与工程学院, 北京 100191

基金项目: 国家自然科学基金资助项目(51178020); 亚热带建筑科学国家重点实验室重点开放课题资助项目(2013KA03); 国家自然科学基金青年基金资助项目(51108015)

详细信息

作者简介:
耿娇(1987-),女,云南宣威人,硕士生,gegjiao0202@sina.com.

中图分类号: TU582
计量
- 文章访问数: 1469
- HTML全文浏览量: 162
- PDF下载量: 649
- 被引次数: 0
出版历程
- 收稿日期: 2012-12-05
- 网络出版日期: 2013-10-30

Degradation mechanism of air-entrained concrete under alternative actions of freeze-thaw cycles and seawater immersion

School of Transportation Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191, China

摘要

摘要: 对经历冻融循环和海水浸泡交替作用后含气量为5.9%的引气混凝土试件进行抗压强度、质量损失、相对动弹性模量及扫描电子显微镜检测,以研究冻融循环和海水浸泡交替作用下引气混凝土的劣化机理.通过观察引气混凝土试件表面和中间处的微观结构,发现未受到冻融循环时,几乎不见裂缝和晶体,随着冻融循环次数增加,微裂缝逐渐发展,当冻融循环达到300次时,主裂缝深入发展,并有晶体产生.可见海水侵蚀和冻融循环交替作用,导致微裂缝产生并发展,同时化学反应产生了晶体.物理和化学损伤累积导致引气混凝土抗压强度降低达8.5%,但是相对动弹性模量和质量损失在冻融循环和海水浸泡交替作用前后均变化较小.
- 引气混凝土 /
- 冻融循环 /
- 劣化机理 /
- 裂缝 /
- 晶体
Abstract: Experiments had been done on air-entrained concrete test cubes(air content is 5.9%) experienced alternative actions of freeze-thaw cycles in the seawater to explore the properties deterioration mechanism via testing the compressive strength, the relative dynamic elastic modulus and the mass loss. Then, observing the microstructure of the concrete by scanning electron microscope (SEM). The SEM observation shows that there was barely cracks and crystals in the normally cured concrete, but cracks emerged and gradually developed as the times of freeze-thaw cycle increased. The main cracks developed further and crystals emerged in the concrete experienced 300 cycles. The results show that the alternative actions of freeze-thaw cycles and seawater immersion give rise to the emergence and development of the cracks, chemical reactions produce some dilatability crystals. Both of the physical changes and the chemical reactions make the compressive strength decrease by 8.5%, but have no apparent influence on the relative dynamic elastic modulus and the mass loss.
- air-entrained concrete /
- freeze-thaw cycle /
- deterioration mechanism /
- cracks, crystals /

HTML全文

参考文献(1)

[1] Ringota E,Bascou A.About the analysis of microcracking in concrete[J].Cement & Concrete Composites,2001,22(3):261-266 [2] Promentilla B,Angelo M,Takafumi S.X-Ray micro tomography of mortars exposed to freezing-thawing action[J].Journal of Advanced Concrete Technology,2010,8,97-111 [3] Sun Zhenhua,Scherer G W.Effect of air voids on salt scaling and internal freezing[J].Cement and Concrete Research,2009,9:260-270 [4] 金祖权,孙伟,张云升,等.混凝土在硫酸盐、氯盐溶液中的损伤过程[J].硅酸盐学报,2006,34 (5):630-635 Jin Zuquan,Sun Wei,Zhang Yunsheng,et al.Damage of concrete in sulfate and chloride solution[J].Journal of the Chinese Ceramic Society,2006,34 (5):630-635(in Chinese) [5] 慕儒,缪昌文,刘加平,等.氯化钠、硫酸钠溶液对混凝土抗冻性的影响及其机理[J].硅酸盐学报,2001,29(6): 523-529 Mu Ru,Miao Changwen,Liu Jiaping,et al.Effect of NaCl and Na2SO4 solution on the frost resistance of concrete and it's mechanism[J].Journal of the Chinese Ceramic Society,2001, 29(6) : 523-529(in Chinese) [6] Shang Huaishuai,Song Yupu,Ou Jinping.Behavior of air-entrained concrete after freeze-thaw cycles[J].Acta Mechanica Solida Sinica,2009,22(3):261-266 [7] Shang H S,Song Y P,Ou J P.Mechanical behaviour of air-entrained concrete[J].Magazine of Concrete Research,2009, 61(2) :87-94 [8] 高润东,李庆斌.复杂环境下混凝土硫酸盐侵蚀微-宏观劣化规律研究[D].北京:清华大学水利水电工程系,2010 Gao Rundong,Li Qingbin.Micro-Macro degradation regularity of sulfate attack on concrete under complex environments[D].Beijing: Hydraulic Engineering,Tsinghua University,2010(in Chinese) [9] 郑晓宁,刁波,孙洋.混合侵蚀与冻融交替作用下持续承载RC梁性能劣化机理研究[J].建筑结构学报,2009,12:287-291 Zheng Xiaoning,Diao Bo,Sun Yang.Properties deterioration mechanism of RC beams sustained loading under alternative actions of mix-aggressive solution and freeze-thaw circles[J].Journal of Building Structures,2009,12:287-291(in Chinese) [10] 李淑进,赵铁军,吴科如.混凝土渗透性与微观结构关系的研究[J].混凝土与水泥制品,2004(4):6-8 Li Shujin,Zhao Tiejun,Wu Keru.Relations of concrete permeability and micro structure[J].China Concrete and Cement Products,2004(4):6-8(in Chinese) [11] Zhang Zhenyu,Dai Changlu,Zhang Quanchang,et al.Research on formation mechanism of as 5-phase and as 3-phase[J].Chinise Sciense B,1991(1):82-89 [12] 王佩玲,王心磊,黄月鸿,等.氯镁水泥硬化体的显微结构及结构强度[J].无机材料学报,1990,5(1) :61-67 Wang Peiling,Wang Xinlei,Huang Yuehong,et al.Micro structure and structural strength of hardened magnesium oxychloride cement[J].Journal of Inorganic Materials,1990,5(1):61-67(in Chinese)

施引文献

资源附件(0)

访问统计