Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature

Foam concrete is conventionally used in non-structural applications (e.g. thermal and acoustic insulation) due to its lightweight nature and poor mechanical properties. However, interest in adopting foam concrete as structural components has increased phenomenally in recent years due to its lightwei...

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Main Authors: Wang, Su, Ng, Yan Hao, Tan, Kang Hai, Dasari, Aravind
Other Authors: School of Civil and Environmental Engineering
Format: Article
Language:English
Published: 2022
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Online Access:https://hdl.handle.net/10356/162323
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1623232022-10-14T05:52:23Z Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature Wang, Su Ng, Yan Hao Tan, Kang Hai Dasari, Aravind School of Civil and Environmental Engineering Engineering::Civil engineering Engineering::Materials Ultrahigh Performance Concrete Thermal Properties Foam concrete is conventionally used in non-structural applications (e.g. thermal and acoustic insulation) due to its lightweight nature and poor mechanical properties. However, interest in adopting foam concrete as structural components has increased phenomenally in recent years due to its lightweight and sustainable feature. A new type of foam concrete termed as carbon nanofibers enhanced lightweight cementitious composite (CNF-LCC) was developed by blending micro-foam bubbles with carbon nanofibers enhanced ultra-high performance concrete; it has superior mechanical properties, long-term properties and bond performance with steel bar compared with conventional foam concrete. In this paper, thermal properties of CNF-LCC during heating were investigated and compared with normal weight concrete (NWC) and lightweight aggregate concrete (LWAC). From room temperature to 800 ℃, the thermal diffusivity of CNF-LCC was lower than NWC and similar to LWAC while the specific heat and thermal conductivity of CNF-LCC was lower than both NWC and LWAC. CNF-LCC showed better structural efficiency than NWC and LWAC in combination of mechanical and thermal insulation properties. The measured thermal insulation properties under high temperature were verified by conducting one-dimensional heat transfer tests and numerical analysis on CNF-LCC blocks. Furthermore, the thermal strain of CNF-LCC during heating is lower and more stable than NWC and LWAC. Dehydration reaction at isothermal elevated temperature was characterised for the analysis of experimental results. Foam bubbles could reduce both thermal insulation and strain properties while a low dosage of CNFs had minimum effect on the thermal insulation properties but could improve the mechanical properties and decrease the thermal shrinkage. CNF-LCC showed potential for fire resistant as a structural lightweight concrete due to the excellent thermal insulation and lower thermal strain properties. The authors would like to acknowledge financial and materials support from ceEntek Pte Ltd. 2022-10-14T05:29:09Z 2022-10-14T05:29:09Z 2021 Journal Article Wang, S., Ng, Y. H., Tan, K. H. & Dasari, A. (2021). Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature. Construction and Building Materials, 307, 124358-. https://dx.doi.org/10.1016/j.conbuildmat.2021.124358 0950-0618 https://hdl.handle.net/10356/162323 10.1016/j.conbuildmat.2021.124358 2-s2.0-85115410493 307 124358 en Construction and Building Materials © 2021 Elsevier Ltd. All rights reserved.
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Civil engineering
Engineering::Materials
Ultrahigh Performance Concrete
Thermal Properties
spellingShingle Engineering::Civil engineering
Engineering::Materials
Ultrahigh Performance Concrete
Thermal Properties
Wang, Su
Ng, Yan Hao
Tan, Kang Hai
Dasari, Aravind
Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature
description Foam concrete is conventionally used in non-structural applications (e.g. thermal and acoustic insulation) due to its lightweight nature and poor mechanical properties. However, interest in adopting foam concrete as structural components has increased phenomenally in recent years due to its lightweight and sustainable feature. A new type of foam concrete termed as carbon nanofibers enhanced lightweight cementitious composite (CNF-LCC) was developed by blending micro-foam bubbles with carbon nanofibers enhanced ultra-high performance concrete; it has superior mechanical properties, long-term properties and bond performance with steel bar compared with conventional foam concrete. In this paper, thermal properties of CNF-LCC during heating were investigated and compared with normal weight concrete (NWC) and lightweight aggregate concrete (LWAC). From room temperature to 800 ℃, the thermal diffusivity of CNF-LCC was lower than NWC and similar to LWAC while the specific heat and thermal conductivity of CNF-LCC was lower than both NWC and LWAC. CNF-LCC showed better structural efficiency than NWC and LWAC in combination of mechanical and thermal insulation properties. The measured thermal insulation properties under high temperature were verified by conducting one-dimensional heat transfer tests and numerical analysis on CNF-LCC blocks. Furthermore, the thermal strain of CNF-LCC during heating is lower and more stable than NWC and LWAC. Dehydration reaction at isothermal elevated temperature was characterised for the analysis of experimental results. Foam bubbles could reduce both thermal insulation and strain properties while a low dosage of CNFs had minimum effect on the thermal insulation properties but could improve the mechanical properties and decrease the thermal shrinkage. CNF-LCC showed potential for fire resistant as a structural lightweight concrete due to the excellent thermal insulation and lower thermal strain properties.
author2 School of Civil and Environmental Engineering
author_facet School of Civil and Environmental Engineering
Wang, Su
Ng, Yan Hao
Tan, Kang Hai
Dasari, Aravind
format Article
author Wang, Su
Ng, Yan Hao
Tan, Kang Hai
Dasari, Aravind
author_sort Wang, Su
title Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature
title_short Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature
title_full Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature
title_fullStr Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature
title_full_unstemmed Thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature
title_sort thermal properties of carbon nanofibers enhanced lightweight cementitious composite under high temperature
publishDate 2022
url https://hdl.handle.net/10356/162323
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