Characteristics of Freeze-thaw Damage of Pore Structure in Concrete Material Using Nuclear Magnetic Resonance Technology

YANG Jing

doi:10.11988/ckyyb.20190045

PDF(3655 KB)

Journal of Changjiang River Scientific Research Institute ›› 2020, Vol. 37 ›› Issue (4) : 127-131. DOI: 10.11988/ckyyb.20190045

HYDRAULIC STRUCTURE AND MATERIAI

Characteristics of Freeze-thaw Damage of Pore Structure in Concrete Material Using Nuclear Magnetic Resonance Technology

YANG Jing

Author information +

History +

Abstract

In the purpose of obtaining variation characteristics of pore distribution for material under freeze-thaw cycles, Nuclear magnetic resonance (NMR) technique was employed in this research to scan concrete specimens undergone 0, 50, 100, and 200 times of freeze-thaw cycles. The spectrum of relaxation time T₂ and NMR scanning images were acquired. The variation of T₂ distribution curve reflected the evolution and expansions of pores in the specimen undergone freeze-thaw cycles. With the proceeding of cyclic freezing and thawing, the T₂ spectral area which characterizes the porosity of the materials surged in the initial stage; but such increment attenuated later. The proportion of small pores reduced whereas the ratio of macropores increased. The NMR scanning images of concrete specimen with various damage degrees synchronized well with the variations of T₂ distribution spectrum, which implied the accuracy of scanning results. In conclusion, the joint failure due to the combined action of osmotic force and frost heave force in freeze-thaw cycles is the fundamental cause for the formation of connecting fracture.

Key words

concrete / NMR / freeze-thaw cycles / pore structure / damage characteristic

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

YANG Jing. Characteristics of Freeze-thaw Damage of Pore Structure in Concrete Material Using Nuclear Magnetic Resonance Technology[J]. Journal of Changjiang River Scientific Research Institute. 2020, 37(4): 127-131 https://doi.org/10.11988/ckyyb.20190045

References

[1]GOKCE A, NAGATAKI S, SAEKI T, et al. Freezing and Thawing Resistance of Air-entrained Concrete Incorporating Recycled Coarse Aggregate: The Role of Air Content in Demolished Concrete[J]. Cement & Concrete Research, 2004, 34(5):799-806.
[2] 汪在芹,李家正,周世华,等.冻融循环过程中混凝土内部微观结构的演变[J].混凝土,2012(1):13-14.
[3] MOHAMMED T U,HAMBDA H. Relationship between Free Chloride and Total Chloride Contents in Concrete[J].Cement and Concrete Research,2003,33(9):1487-1490.
[4] 刘建勋,赵文斌,张戎令,等.极旱、大温差地区养护方式对混凝土桥墩性能的影响[J].raybet体育在线院报,2018,35(12):148-153.
[5] 田威,谢永利,党发宁.冻融环境下混凝土力学性能试验及损伤演化[J].四川大学学报(工程科学版),2015,47(4):38-44.
[6] 李杰林,周科平,张亚民,等.基于核磁共振技术的岩石孔隙结构冻融损伤试验研究[J].岩石力学与工程学报,2012,31(6):1208-1214.
[7] 刘红岩,刘冶,邢闯锋,等.循环冻融条件下节理岩体损伤破坏试验研究[J].岩土力学,2014,35(6):1547-1554.
[8] LEECH C, LOCKINGTON D, DUX P. Unsaturated Diffusivity Functions for Concrete Derived from NMR Images[J]. Materials & Structures, 2003, 36(6): 413-418.
[9] 白松涛,程道解,万金彬,等.砂岩岩石核磁共振T2谱定量表征[J].石油学报,2016,37(3):382-391,414.
[10]刘倩,申向东,薛慧君,等.基于核磁共振技术对不同粗骨料混凝土孔隙特征试验研究[J].功能材料,2017,48(10):10066-10070,10076.
[11]王学兵,王涛,刘劲松.基于低场核磁共振研究掺加磷石膏对水泥硬化体孔结构的影响[J].混凝土与水泥制品,2018(11):82-85.
[12]魏毅萌,柴军瑞,覃源,等.冻融循环下再生混凝土孔隙分布变化及其对抗冻性能的影响[J].硅酸盐通报,2018,37(3):825-830.
[13]陈宝,张康,黄依艺,等.核磁共振技术在非饱和渗透特性研究中的应用[J].raybet体育在线院报,2018,35(3):59-64.
[14]邹欲晓,申向东,李根峰,等.MgSO₄冻融循环作用下风积沙混凝土的微观孔隙研究[J].建筑材料学报,2018,21(5):817-824.
[15]FAURE P, PETER U, LESUEUR D, et al. Water Transfers within Hemp Lime Concrete Followed by NMR[J]. Cement & Concrete Research, 2012, 42(11):1468-1474.