全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...

预测水化水泥浆体离子扩散性能的一种新方法

Full-Text   Cite this paper   Add to My Lib

Abstract:

为了预测水泥基复合材料的离子扩散性能并进而将其用于耐久性研究与寿命预测模型中,基于Einstein–Smoluchowski公式,提出了一个将宏观离子扩散行为和微观粒子Brown运动相关联的方法。为了验证这个方法的可靠性,首先用计算机模拟的方法生成一个水化水泥浆体的微观结构(HYMOSTRUC3D),然后用自回避随机行走算法预测这个微观结构的离子有效扩散系数。在这个过程中,应用统计分析的方法确定了水泥浆体微观结构的代表性体积单元的大小,此后在这个代表性体积单元的基础上,通过与文献数据比较,验证了用该方法预测水泥浆体宏观氯离子扩散行为的合理性,最后应用该方法预测了水泥浆体氯离子有效扩散系数随水胶比和养护龄期变化的关系。

References

[1]  LIU L, SUN W, CHEN H S, et al. Prediction of effective diffusion coefficient of concrete based on multiscale approach [C]//KOVLER K ed. Concrete Durability and Service Life Planning – ConcreteLife’09. Bagneux, France: RILEM publications SARL, 2009: 423–431. [2] ZHENG J, ZHOU X. Analytical solution for the chloride diffusivity of hardened cement paste [J]. J Mater Civ Eng, 2008, 20(5): 384–391. [3] EUROPEAN UNION, DuraCrete probabilistic performance based durability design of concrete structures [R]. BE95–1347/R17, 2000: 44. [4] BOCKRIS J O M, REDDY A K N. Modern Electrochemistry. Vol.1 Ionics [M]. New York: Plenum, 2002. [5] CRANK J. The Mathematics of Diffusion [M]. 2nd Ed, Oxford: Clar-endon, 1975: 4. [6] NAKASHIMA Y, KAMIYA S. Mathermatica programs for the analysis of three-dimensional pore connectivity and anisotropic tortuosity of porous rocks using X-ray computed tomography image date [J]. J Nucl Sci Techol, 2007, 44(9): 1233–1247. [7] TUMIDAJSKI P J, SCHUMACHER A S, PERRON S, et al. On the relationship between porosity and electrical resistivity in cementitious systems [J]. Cem Concr Res, 1996, 26(4): 539–544. [8] PROMENTILLA M A B, SUGIYAMA T, HITOMI T, et al. Quan- tification of tortuosity in hardened cement pastes using synchrotron- based X-ray computed microtomography [J]. Cem Concr Res, 2009, 39(6): 548–557. [9] TRTIK P, MUNCH B, LURA P. A critical examination of statistical nanoindentation on model materials and hardened cement pastes based on virtual experiments [J]. Cem Concr Compos, 2009, 31(10): 705– 714. [10] van BREUGEL K. Simulation of hydration and formation of structure in hardening cement-based materials [D]. Delft: Delft University of Technology, 1991. [11] CHEN H S, STROEVEN P, YE G, et al. Influence of boundary condi-tions on pore percolation in model cement paste [J]. Key Eng Mater, 2006, 302–303: 486–492. [12] YE G, VAN BREUGEL K, FRAAIJ A L. Three-dimensional microstructure analysis of numerically simulated cementitious materials [J]. Cem Concr Res, 2003, 33(2): 215–222. [13] GHONIEM A F, SHERMAN F S. Grid-free simulation of diffusion using random walk methods [J]. J Comput phys, 1985, 61(1): 1–37. [14] VAMOS C, SUCIU N, VEREECKEN H. Generalized random walk algorithm for the numerical modeling of complex diffusion process [J]. J Comput Phys, 2003, 186(2): 527–544. [15] BENTZ D P, DETWILER R J, GARBOCZI E J, et al. Multi-scale modelling of the diffusivity of mortar and concrete [C]//NILSSON L O, OLLIVIER J P, eds., Proceedings of Chloride Penetration into Con-crete, Saint-Rémy-lès-Chevreuse, France: RILEM publications SARL, 1997: 85–94. [16] MADRAS N, SLADE G. The Self-Avoiding Walk [M]. Boston: Birk-hauser, 1996. [17] TANG L, NILSSON L-O. Rapid determination of the chloride diffusi- vity in concrete by applying an electrical field [J]. ACI Mater J, 1992, 89(1): 49–53. [18] NGALA V T, PAGE C L, PARROTT L J, et al. Diffusion in cementi- tious materials: II, further investigations of chloride and oxygen diffu-sion in well-cured OPC and OPC/30%PFA pastes [J]. Cem Concr Res, 1995, 25(4): 819–826. [19] PAGE C L, SHORT N R, TARRAS A El. Diffusion of chloride ions in hardened cement pastes [J]. Cem Concr Res, 1981, 11(3): 395–406. [20] LIDE D. CRC Handbook of Chemistry and Physics [M]. 89st ed, Washington DC: CRC Press, 2008. [21] GITMAN I M, ASKES H, SLUYS L J. Representative volume: exis-tence and size determination [J]. Eng Fract Mech, 2007, 74(16): 2518– 2534. [22] NIST/SEMATECH. e-Handbook of Statistical Methods. http:// www. itl.nist.gov/div898/handbook/, 2010. [23] YU S W, PAGE C L. Diffusion in cementitous materials: 1. compa- rative study of chloride and oxygen diffusion in hydrated cement pastes [J]. Cem Concr Res, 1991, 21(4): 581–588.

Full-Text

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133