Skip to main content
Log in

Thermal conductivity and specific volume heat capacity of bentonite–fly ash-based fluidized thermal backfill

  • Published:
Journal of Thermal Analysis and Calorimetry Aims and scope Submit manuscript

Abstract

Thermal characteristics such as thermal conductivity and specific volume heat capacity are the significantly important parameters for the backfill materials for underground power cable. Herein, the thermal characteristics of fly ash (fluidizer), bentonite, and their mixes (fly ash content: 20%, 40%, 50%, and 70% by mass) were measured using a KD2 Pro thermal probe, and the effect of fly ash content and volumetric water content were studied. The experimental results indicate that the thermal conductivity and specific volume heat capacity increased with increase in the fly ash content and the volumetric water content. Further, a correlation between thermal conductivity versus volumetric air content and fly ash has been established based on experimental results. The established correlation was verified with the data obtained from the present study as well as from the data available in existing works of the literature. The proposed calculation model estimated the thermal conductivity with relative error of 8.53–16.40% of bentonite and bentonite–fly ash mixture. The predicted result showed that the established correlation will be useful to predict the thermal conductivity of bentonite–fly ash or similar soil and soil mixtures. The experimental outcomes can be widely applicable for thermal backfill applications for underground power cable systems.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10

Similar content being viewed by others

Availability of data and materials

The data of this study are available from the corresponding author upon reasonable request.

References

  1. Ocłoń P, Bittelli M, Cisek P, Kroener E, Pilarczyk M, Taler D, et al. The performance analysis of a new thermal backfill material for underground power cable system. Appl Therm Eng. 2016;108:233–50.

    Google Scholar 

  2. Maximov S, Venegas V, Guardado JL, Moreno EL, López R. Analysis of underground cable ampacity considering non-uniform soil temperature distributions. Electr Power Syst Res. 2016;132:22–9.

    Google Scholar 

  3. Suleiman BM, Daoudi K, Attaelmanan AG, Alzaylaie M, Gustavsson M. Modified clay as thermal backfill material for buried electrical cables. Therm Sci Eng Prog. 2020;19: 100589.

    Google Scholar 

  4. de León F, Anders GJ. Effects of backfilling on cable ampacity analyzed with the finite element method. IEEE Trans Power Deliv. 2008;23:537–43.

    Google Scholar 

  5. Ocłoń P, Cisek P, Matysiak M. Analysis of an application possibility of geopolymer materials as thermal backfill for underground power cable system. Clean Technol Environ Policy. 2021;23:869–78.

    Google Scholar 

  6. Gouda OE, Osman GFA. Enhancement of the thermal analysis of power cables installed in polyvinyl chloride (PVC) ducts under continuous and cyclic current loading conditions. IET Gener Transm Distrib. 2021;15:1144–58.

    Google Scholar 

  7. Salata F, Nardecchia F, Gugliermetti F, De Lieto VA. How thermal conductivity of excavation materials affects the behavior of underground power cables. Appl Therm Eng. 2016;100:528–37.

    Google Scholar 

  8. Gouda OES, Osman GFA, Salem WAA, Arafa SH. Cyclic loading of underground cables including the variations of backfill soil thermal resistivity and specific heat with temperature variation. IEEE Trans Power Deliv. 2018;33:3122–9.

    Google Scholar 

  9. Metwally IA, Al-Badi AH, Al Farsi AS. Factors influencing ampacity and temperature of underground power cables. Electr Eng. 2013;95:383–92.

    Google Scholar 

  10. Javadi H, Ajarostaghi SSM, Rosen MA, Pourfallah M. A comprehensive review of backfill materials and their effects on ground heat exchanger performance. Sustainability. 2018;10:4486.

    Google Scholar 

  11. Park K, Lee J, Yoon HK, Kim D. Hydraulic and thermal conductivities of kaolin-silica mixtures under different consolidation stresses. Mar Georesources Geotechnol. 2016;34:532–41.

    CAS  Google Scholar 

  12. Tang AM, Cui YJ, Le TT. A study on the thermal conductivity of compacted bentonites. Appl Clay Sci. 2008;41:181–9.

    CAS  Google Scholar 

  13. Xu Y, Chung DDL. Effect of sand addition on the specific heat and thermal conductivity of cement. Cem Concr Res. 2000;30:59–61.

    CAS  Google Scholar 

  14. Li HF, Chen MQ, Fu BA, Liang B. Evaluation on the thermal and moisture diffusion behavior of sand/bentonite. Appl Therm Eng. 2019;151:55–65.

    CAS  Google Scholar 

  15. Mahmoud M, Ramadan M, Pullen K, Abdelkareem MA, Wilberforce T, Olabi AG, et al. A review of grout materials in geothermal energy applications. Int J Thermofluids. 2021;10: 100070.

    CAS  Google Scholar 

  16. Cho WJ, Lee JO, Kwon S. An empirical model for the thermal conductivity of compacted bentonite and a bentonite-sand mixture. Heat Mass Transf und Stoffuebertragung. 2011;47:1385–93.

    Google Scholar 

  17. Agrawal KK, Misra R, Das AG. Improving the thermal performance of ground air heat exchanger system using sand-bentonite (in dry and wet condition) as backfilling material. Renew Energy. 2020;146:2008–23.

    Google Scholar 

  18. Chen YG, Liu XM, Mu X, Ye WM, Cui YJ, Chen B, et al. Thermal conductivity of compacted GO-GMZ bentonite used as buffer material for a high-level radioactive waste repository. Adv Civ Eng. 2018;2018:1–11.

    Google Scholar 

  19. Peng F, Tan Y, Sun D. Thermal conductivity of bentonite-graphite mixture and its prediction for high-level radioactive waste repository. Ann Nucl Energy. 2021;154: 108142.

    CAS  Google Scholar 

  20. Liang B, Chen M, Guan J. Assessment on the thermal and moisture migration of sand-based materials coupled with kaolin additive. J Therm Anal Calorim. 2022;147:10163–76.

    CAS  Google Scholar 

  21. Gupt CB, Bordoloi S, Sahoo RK, Sekharan S. Mechanical performance and micro-structure of bentonite-fly ash and bentonite-sand mixes for landfill liner application. J Clean Prod. 2021;292: 126033.

    CAS  Google Scholar 

  22. Lini Dev K, Robinson RG. Pond ash based controlled low strength flowable fills for geotechnical engineering applications. Int J Geosynth Gr Eng. 2015;1:1–13.

    Google Scholar 

  23. Kaliyavaradhan SK, Ling TC, Guo MZ. Upcycling of wastes for sustainable controlled low-strength material: A review on strength and excavatability. Environ Sci Pollut Res. 2022;29:16799–816.

    CAS  Google Scholar 

  24. Alrtimi AA, Rouainia M, Manning DAC. Thermal enhancement of PFA-based grout for geothermal heat exchangers. Appl Therm Eng. 2013;54:559–64.

    Google Scholar 

  25. Do TM, Kang GO, Kim YS. Thermal conductivity of controlled low strength material (CLSM) under various degrees of saturation using a modified pressure plate extractor apparatus—a case study for geothermal systems. Appl Therm Eng. 2018;143:607–13.

    Google Scholar 

  26. Sang KY, Do TM, Kim MJ, Kim BJ, Kim HK. Utilization of by-product in controlled low-strength material for geothermal systems: engineering performances, environmental impact, and cost analysis. J Clean Prod. 2018;172:909–20.

    Google Scholar 

  27. Dinh BH, Sang KY, Kang GO. Thermal conductivity of steelmaking slag-based controlled low-strength materials over entire range of degree of saturation: a study for ground source heat pump systems. Geothermics. 2020;88:101910.

    Google Scholar 

  28. Sang KY, Do TM, Ki KH, Kang G. Utilization of excavated soil in coal ash-based controlled low strength material (CLSM). Constr Build Mater. 2016;124:598–605.

    Google Scholar 

  29. Ramme BW, Scholer CF. ACI 229R-99 Controlled Low-strength materials. Am Concr Inst. 1999;1–15.

  30. Do TM, Do AN, Kang GO, Kim YS. Utilization of marine dredged soil in controlled low-strength material used as a thermal grout in geothermal systems. Constr Build Mater. 2019;215:613–22.

    Google Scholar 

  31. Kolay PK, Singh DN. Application of coal ash in fluidized thermal beds. J Mater Civ Eng. 2002;14:441–4.

    CAS  Google Scholar 

  32. Sah PK, Sreedeep S. Evaluation of bentonite-based thermal backfill materials. Environ Geotech. 2014;1:179–88.

    Google Scholar 

  33. Choorackal E, Riviera PP, Dalmazzo D, Santagata E, Zichella L, Marini P. Performance-related characterization of fluidized thermal backfills containing recycled components. Waste Biomass Valor. 2020;11:5393–404.

    CAS  Google Scholar 

  34. Do TM, Kim HK, Kim MJ, Kim YS. Utilization of controlled low strength material (CLSM) as a novel grout for geothermal systems: laboratory and field experiments. J Build Eng. 2020;29: 101110.

    Google Scholar 

  35. ASTM. Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use. Annu B ASTM Stand. 2010;3–6.

  36. Sah PK, Shankar S, Sreedeep KS. Thermophysical properties of bentonite—sand/fly ash-based materials for underground power cable. Int J Thermophys. 2023;44:57.

    CAS  Google Scholar 

  37. Priyadarshee A, Gupta D, Kumar V, Sharma V. Comparative study on performance of tire crumbles with fly ash and kaolin clay. Int J Geosynth Gr Eng. 2015;1:1–7.

    Google Scholar 

  38. Decagon Devices I. KD2 Pro thermal Properties analyzer. 2016;1–71.

  39. Bristow KL, White RD, Kluitenberg GJ. Comparison of single and dual probes for measuring soil thermal properties with transient heating. Soil Res. 1994;32:447–64.

    Google Scholar 

  40. Abu-Hamdeh NH. Thermal properties of soils as affected by density and water content. Biosyst Eng. 2003;86:97–102.

    Google Scholar 

  41. Nikoosokhan S, Nowamooz H, Chazallon C. Effect of dry density, soil texture and time-spatial variable water content on the soil thermal conductivity. Geomech Geoengin. 2016;11:149–58.

    Google Scholar 

  42. Zhang T, Jin WC, Yu WC, Zhang N, Wei ZT. Assessment of soil thermal conduction using artificial neural network models. Cold Reg Sci Technol. 2020;169:102907.

    Google Scholar 

  43. Yan X, Duan Z, Sun Q. Influences of water and salt contents on the thermal conductivity of loess. Environ Earth Sci. 2021;80:1–14.

    Google Scholar 

  44. Zhao Y, Si B. Thermal properties of sandy and peat soils under unfrozen and frozen conditions. Soil Tillage Res. 2019;189:64–72.

    Google Scholar 

  45. Singh DN, Devid K. Generalized relationships for estimating soil thermal resistivity. Exp Therm Fluid Sci. 2000;22:133–43.

    CAS  Google Scholar 

  46. Zhao Y, Si B, Zhang Z, Li M, He H, Hill RL. A new thermal conductivity model for sandy and peat soils. Agric For Meteorol. 2019;274:95–105.

    Google Scholar 

  47. Manh Do T, Kim Y-S, Kang G-O, Quoc Tran T. Thermal conductivity of controlled low strength material (CLSM). 2–3.

  48. Liang B, Chen M, Orooji Y. Effective parameters on the performance of ground heat exchangers: a review of latest advances. Geothermics. 2022;98: 102283.

    Google Scholar 

  49. He H, Li M, Dyck M, Si B, Wang J, Lv J. Modelling of soil solid thermal conductivity. Int Commun Heat Mass Transf. 2020;116: 104602.

    Google Scholar 

  50. Różański A. Relating thermal conductivity of soil skeleton with soil texture by the concept of local thermal conductivity fluctuation. J Rock Mech Geotech Eng. 2022;14:262–71.

    Google Scholar 

  51. Tong B, Kool D, Heitman JL, Sauer TJ, Gao Z, Horton R. Thermal property values of a central Iowa soil as functions of soil water content and bulk density or of soil air content. Eur J Soil Sci. 2020;71:169–78.

    Google Scholar 

  52. Zhi TY, Yang XZ, Peng F, Hong QF, Jun MH. Optimal mixing scheme for graphite–bentonite mixtures used as buffer materials in high-level waste repositories. Environ Earth Sci. 2021;80:1–13.

    Google Scholar 

  53. Tian Z, Ren T, Heitman JL, Horton R. Estimating thermal conductivity of frozen soils from air-filled porosity. Soil Sci Soc Am J. 2020;84:1650–7.

    CAS  Google Scholar 

  54. Rashid HMA, Sardar A, Ismail A. Geotechnical characterization of bentonite-fly ash mixtures for their application as landfill liner in Pakistan. Arab J Geosci. 2021;14.

  55. Tang AM, Cui YJ, Barnel N. Thermo-mechanical behaviour of a compacted swelling clay. Geotechnique. 2008;58:45–54.

    Google Scholar 

Download references

Acknowledgements

The authors are very thankful to Prof. Sreedeep S., Indian Institute of Technology Guwahati, Assam and Indian Institute of Technology Guwahati, Assam, for providing the facilities to conduct the experiments and their kind support during this study.

Funding

Not applicable.

Author information

Authors and Affiliations

Authors

Contributions

PKS contributed to conceptualization, methodology, laboratory work, writing—original draft preparation. SSK contributed to conceptualization, formal analysis, writing—review and editing, and supervision. SS contributed to conceptualization, formal analysis, review and editing and supervision.

Corresponding author

Correspondence to Pawan Kishor Sah.

Ethics declarations

Conflict of interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Sah, P.K., Kumar, S.S. & Sreedeep, S. Thermal conductivity and specific volume heat capacity of bentonite–fly ash-based fluidized thermal backfill. J Therm Anal Calorim 148, 11607–11617 (2023). https://doi.org/10.1007/s10973-023-12523-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10973-023-12523-4

Keywords

Navigation