Estimating thermal conductivity of lightweight nanoporous cement pastes using a hybrid fractal model

TY - JOUR

T1 - Estimating thermal conductivity of lightweight nanoporous cement pastes using a hybrid fractal model

AU - Jiang, Jun

AU - Zheng, Li

AU - Roderick Jones, M.

AU - Lu, Zhongyuan

AU - Li, Jun

N1 - Funding Information: The authors would also like to acknowledge the funding from Open Project of State Key Laboratory of Environment-friendly Energy Materials (19kfhg16), Natural Science Foundation of Southwest University of Science and Technology (20zx7102), and the Science and Technology Project of Sichuan Province (No.2019ZDZX0024). Publisher Copyright: © 2022 Elsevier Ltd

PY - 2022/4/11

Y1 - 2022/4/11

N2 - Nanoporous cement paste (NCP) has been successfully prepared by adding nanopore-forming agent into cement paste, and the measured effective thermal conductivity (λe) of NCP shows that it has excellent thermal insulation performance. To promote NCP design and application, λe estimation is essential. In this paper, a hybrid fractal model (HFM) was developed based on fractal theory and related iterative algorithm using Sierpinski carpets, and electrical equivalent theory. Subsequently, this model was validated with published data and then used to predict the λe of the NCPs prepared. The results indicated that the multi-scale pore structure of NCPs was well simulated by the HFM with randomly generated Sierpinski carpet combinations. Having considered Knudsen effect of nanoporous structure, the λe of the NCPs could be well estimated using iterative algorithm, and the mean relative deviation was low to 4.2%, giving confidence in the application of the HFM method to nanoporous materials.

AB - Nanoporous cement paste (NCP) has been successfully prepared by adding nanopore-forming agent into cement paste, and the measured effective thermal conductivity (λe) of NCP shows that it has excellent thermal insulation performance. To promote NCP design and application, λe estimation is essential. In this paper, a hybrid fractal model (HFM) was developed based on fractal theory and related iterative algorithm using Sierpinski carpets, and electrical equivalent theory. Subsequently, this model was validated with published data and then used to predict the λe of the NCPs prepared. The results indicated that the multi-scale pore structure of NCPs was well simulated by the HFM with randomly generated Sierpinski carpet combinations. Having considered Knudsen effect of nanoporous structure, the λe of the NCPs could be well estimated using iterative algorithm, and the mean relative deviation was low to 4.2%, giving confidence in the application of the HFM method to nanoporous materials.

KW - Effective thermal conductivity

KW - Fractal theory

KW - Knudsen effect

KW - Lightweight nanoporous cement paste

KW - Sierpinski carpet

UR - https://www.scopus.com/pages/publications/85125282546

U2 - 10.1016/j.conbuildmat.2022.126941

DO - 10.1016/j.conbuildmat.2022.126941

M3 - Article

AN - SCOPUS:85125282546

SN - 0950-0618

VL - 327

SP - 1

EP - 11

JO - Construction and Building Materials

JF - Construction and Building Materials

M1 - 126941

ER -