干旱区生态环境知识资源中心(Arid): 冻融循环下纤维水泥改良风积沙NMR试验研究

Arid

	冻融循环下纤维水泥改良风积沙NMR试验研究
其他题名	Experimental study by nuclear magnetic resonance on basalt fiber reinforced cement improve aeolian sand under freeze-thaw cycles
	徐长文; 阮波
来源期刊	铁道科学与工程学报
ISSN	1672-7029
出版年	2021
卷号	18 期号:9 页码:2289-2298
中文摘要	新疆和若铁路沿线属于季冻区,路基基床表层采用玄武岩纤维加筋水泥改良风积沙填筑时,运营期间会长期受冻融循环的影响。为了研究冻融循环作用对玄武岩纤维加筋水泥改良风积沙微观结构的影响,对其进行0,4,7,10,14和18次冻融循环条件下的核磁共振试验,单次冻融循环的冻结和融化时间均为12 h,冻结温度和融化温度分别为-20 ℃和20 ℃。研究结果表明:T2时间分布于0.1~10 000 ms之间,随着冻融循环次数增加,纤维水泥改良风积沙的T2谱向右移动,达到14次冻融循环后,T2谱的变化不明显;纤维水泥改良风积沙的小孔和中孔的比例随冻融循环次数的增加而降低,而大孔的比例逐渐提高,14次冻融循环后,孔径分布趋于稳定;纤维水泥改良风积沙的孔隙率和最可几孔径随冻融循环次数呈双曲线增长。本文成果解释了冻融循环作用对纤维水泥改良风积沙力学性能影响的微观机理,对沙漠季冻区铁路路基基床的设计与施工具有参考价值。
英文摘要	The Hetian-Ruoqiang Railway in Xinjiang belongs to seasonal frozen area. When the surface layer of subgrade bed is filled with basalt fiber reinforced cement improve aeolian sand, it will be affected by freeze-thaw cycle for long time during operation. In order to obtain the effect of freeze-thaw cycles on the microstructure of basalt fiber reinforced cement improve aeolian sand, nuclear magnetic resonance tests were carried out under 0, 4, 7, 10, 14 and 18 freeze-thaw cycles. The freezing time and thawing time of a single freeze-thaw cycle were 12 h, and the freezing temperature and thawing temperature were -20 ℃ and 20 ℃ respectively. The results show that T2 time distribution is between 0.1 ms and 10 000 ms. With the increase of freeze-thaw cycles, the T2 spectrum of fiber reinforced cement improve aeolian sand moves to the right. The change of T2 spectrum is not obvious after 14 freeze-thaw cycles. The proportion of small pore and medium pore decreases, while the proportion of large pore increases gradually with the increase of freeze-thaw cycles. The pore size distribution tends to be stable after 14 freeze-thaw cycles. The porosity and the most probable pore size of fiber reinforced cement improve aeolian sand increase hyperbolically with the number of freeze-thaw cycles. The results of this paper explain the micro mechanism of the influence of freeze-thaw cycles on the mechanical properties of fiber reinforced cement improve aeolian sand, and it is of reference value to the design and construction of railway subgrade bed in desert and seasonal frozen areas.
中文关键词	冻融循环 ; 玄武岩纤维 ; 水泥改良风积沙 ; 核磁共振 ; T2谱 ; 孔径分布 ; 孔隙率
英文关键词	freeze-thaw cycle basalt fiber cement improve aeolian sand nuclear magnetic resonance T2 spectrum pore size distribution porosity
类型	Article
语种	中文
收录类别	CSCD
WOS类目	Construction & Building Technology
CSCD记录号	CSCD:7069345
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/377959
作者单位	徐长文, 湖南省铁路第二工程有限公司, 长沙, 湖南 410075, 中国.; 阮波, 中南大学土木工程学院, 长沙, 湖南 410075, 中国.
推荐引用方式 GB/T 7714	徐长文,阮波. 冻融循环下纤维水泥改良风积沙NMR试验研究[J],2021,18(9):2289-2298.
APA	徐长文,&阮波.(2021).冻融循环下纤维水泥改良风积沙NMR试验研究.铁道科学与工程学报,18(9),2289-2298.
MLA	徐长文,et al."冻融循环下纤维水泥改良风积沙NMR试验研究".铁道科学与工程学报 18.9(2021):2289-2298.