Multi-scale method for thermal conductivity of polypropylene fiber reinforced cementitious composites after high temperature

被引：0
|
作者：
Yao X. [1 ]
Han Y. [1 ]
Shen L. [2 ]
Zhu D. [1 ]
Cao M. [2 ]
机构：
[1] School of Civil Engineering, Henan University of Technology, Zhengzhou
[2] Department of Engineering Mechanics, Hohai University, Nanjing
来源：
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | 2021年 / 38卷 / 10期
关键词：
Cementitious composites; Effective thermal conductivity; High temperature; Polypropylene fiber; Thermal resistance cracks;
D O I：
10.13801/j.cnki.fhclxb.20201211.001
中图分类号：
学科分类号：
摘要：
The effective thermal conductivity (ETC) is a key physical parameter for predicting the temperature distribution of concrete structure under fire. Responding to this demand, a multi-scale homogenization method based on the improved Maxwell-Eucken model, considering interfacial thermal resistance and random particle shape, was proposed to estimate the thermal conductivity of cementitious composites after high temperature. Firstly, the thermal conductivity and porosity of mortar, high performance concrete and polypropylene fiber reinforced concrete with thermal treatment at different temperatures (20, 60, 150, 300, 450 and 600℃) were measured and a part of experimental data was used to calibrate the proposed method. Finally, the method was verified by good agreement between experimental data and numerical results of concrete with different heating temperatures and different fiber contents and size. The results show that: The particle shape (fiber length) has a marginal effect on the ETC; The interfacial thermal resistance (ITR) caused by particle and matrix debonding has a significant effect on the ETC, and the ITR coefficient is in direct proportion to the heating temperature; The polypropylene fiber melts and evaporates at high temperature and then the 'tunnel crack' filled with dry air forms a thermal resistance. In addition, the melting and evaporation of soft fine polypropylene fiber adhering on the coarse aggregate surface enhances the ITR effect between aggregate and mortar. © 2021, Editorial Office of Acta Materiae Compositae Sinica. All right reserved.
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页码：3531 / 3542
页数：11
相关论文
共 38 条
  • [11] WANG J F, CARSON J K, NORTH M F, Et al., A new approach to modelling the effective thermal conductivity of heterogeneous materials, International Journal of Heat & Mass Transfer, 49, 17-18, pp. 3075-3083, (2006)
  • [12] ZHANG W P, XING Y S, GU X L., Theoretical models of effective thermal conductivity of concrete based on compo-site materials in mesoscale, Structural Engineers, 28, 2, pp. 39-45, (2012)
  • [13] HU X P, LI X Y, HAN B Q, Et al., Characterization of thermal behavior of foamed concrete by GEM equation, Bulletin of the Chinese Ceramic Society, 33, 10, pp. 2597-2603, (2014)
  • [14] TANG S B, TANG C A, LIANG Z Z, Et al., Numerical study of the influence of material structure on effective thermal conductivity of concrete, Heat Transfer Engineering, 33, 8, pp. 732-747, (2012)
  • [15] ZHANG W P, MIN H G, GU X L, Et al., Mesoscale model for thermal conductivity of concrete, Construction and Building Materials, 98, pp. 8-16, (2015)
  • [16] FU Y F, WONG Y L, TANG C A, Et al., Thermal induced stress and associated cracking in cement-based composite at elevated temperatures-Part Ⅱ: Thermal cracking around multiple inclusions, Cement and Concrete Composites, 26, 2, pp. 113-126, (2004)
  • [17] FU Y F, WONG Y L, TANG C A, Et al., Thermal induced stress and associated cracking in cement-based composite at elevated temperatures--Part I: Thermal cracking around single inclusion, Cement and Concrete Composites, 26, 2, pp. 99-111, (2004)
  • [18] KHOURY G A, WILLOUGHBY B., Polypropylene fibres in heated concrete. Part 1: Molecular structure and materials behaviour, Magazine of Concrete Research, 60, 2, pp. 125-136, (2008)
  • [19] ZHENG W Z, LI H Y, WANG Y., Compressive behaviour of hybrid fiber-reinforced reactive powder concrete after high temperature, Materials and Design, 41, pp. 403-409, (2012)
  • [20] SIMPSON T K., Figures of thought: A literary appreciation of Maxwell's treatise on electricity and magnetism, (2005)
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