Assessment of Lightweight Concrete Thermal Properties at Elevated Temperatures
Structural lightweight concrete (LWC) has recently acquired research importance because of its good thermal insulation properties. However, there is a lack of knowledge about its thermal properties at elevated temperatures. The thermal properties, such as thermal conductivity and specific heat, of p...
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| Format: | Article |
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MDPI AG
2021-10-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/11/21/10023 |
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| author | Juan Enrique Martínez-Martínez Felipe Pedro Álvarez Rabanal Mariano Lázaro Mar Alonso-Martínez Daniel Alvear Juan José del Coz-Díaz |
| author_facet | Juan Enrique Martínez-Martínez Felipe Pedro Álvarez Rabanal Mariano Lázaro Mar Alonso-Martínez Daniel Alvear Juan José del Coz-Díaz |
| author_sort | Juan Enrique Martínez-Martínez |
| collection | DOAJ |
| description | Structural lightweight concrete (LWC) has recently acquired research importance because of its good thermal insulation properties. However, there is a lack of knowledge about its thermal properties at elevated temperatures. The thermal properties, such as thermal conductivity and specific heat, of porous LWC vary depending on the aggregates, air voids, and moisture content of the LWC in question. To study these effects, in this paper, we measured the thermal properties of three types of structural LWCs at different temperatures, combining different characterization techniques, namely, differential scanning calorimetry (DSC), laser flash analysis (LFA), and modified transient plane source (MTPS). Bulk density and porosity were also evaluated. Specific heat is analyzed by the DSC technique from 20 to 1000 °C and the MTPS technique from 20 to 160 °C. Thermal conductivity is studied using MTPS and LFA techniques at temperatures ranging from 20 to 160 °C and 100 to 300 °C, respectively. The results indicate that the thermal properties of LWC are highly affected by moisture content, temperature, and porosity. For LWC, the current Eurocodes 2 and 4 assume a constant value of specific heat (840 J/kg°C). This research reveals variability in temperatures near 150, 450, and 850 °C due to endothermic reactions. Furthermore, for low temperatures, the higher the porosity, the higher the thermal conductivity, while, at high temperatures, the higher the porosity, the lower the thermal conductivity. Thus, Eurocodes 2 and 4 should be updated accordingly. This research contributes to a deeper understanding and more accurate prediction of LWC’s effects on thermal properties at elevated temperatures. |
| first_indexed | 2024-03-10T06:07:07Z |
| format | Article |
| id | doaj.art-006aa8bc93dd4d26865eff02a79edec3 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T06:07:07Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-006aa8bc93dd4d26865eff02a79edec32023-11-22T20:26:35ZengMDPI AGApplied Sciences2076-34172021-10-0111211002310.3390/app112110023Assessment of Lightweight Concrete Thermal Properties at Elevated TemperaturesJuan Enrique Martínez-Martínez0Felipe Pedro Álvarez Rabanal1Mariano Lázaro2Mar Alonso-Martínez3Daniel Alvear4Juan José del Coz-Díaz5GICONSIME Research Group, University of Oviedo, 33204 Gijón, SpainGICONSIME Research Group, University of Oviedo, 33204 Gijón, SpainGIDAI Research Group, University of Cantabria, 39005 Santander, SpainGICONSIME Research Group, University of Oviedo, 33204 Gijón, SpainDirección General de Industria, Energía y Minas, Gobierno de Cantabria, 39011 Santander, SpainGICONSIME Research Group, University of Oviedo, 33204 Gijón, SpainStructural lightweight concrete (LWC) has recently acquired research importance because of its good thermal insulation properties. However, there is a lack of knowledge about its thermal properties at elevated temperatures. The thermal properties, such as thermal conductivity and specific heat, of porous LWC vary depending on the aggregates, air voids, and moisture content of the LWC in question. To study these effects, in this paper, we measured the thermal properties of three types of structural LWCs at different temperatures, combining different characterization techniques, namely, differential scanning calorimetry (DSC), laser flash analysis (LFA), and modified transient plane source (MTPS). Bulk density and porosity were also evaluated. Specific heat is analyzed by the DSC technique from 20 to 1000 °C and the MTPS technique from 20 to 160 °C. Thermal conductivity is studied using MTPS and LFA techniques at temperatures ranging from 20 to 160 °C and 100 to 300 °C, respectively. The results indicate that the thermal properties of LWC are highly affected by moisture content, temperature, and porosity. For LWC, the current Eurocodes 2 and 4 assume a constant value of specific heat (840 J/kg°C). This research reveals variability in temperatures near 150, 450, and 850 °C due to endothermic reactions. Furthermore, for low temperatures, the higher the porosity, the higher the thermal conductivity, while, at high temperatures, the higher the porosity, the lower the thermal conductivity. Thus, Eurocodes 2 and 4 should be updated accordingly. This research contributes to a deeper understanding and more accurate prediction of LWC’s effects on thermal properties at elevated temperatures.https://www.mdpi.com/2076-3417/11/21/10023lightweight concretethermal conductivityspecific heatelevated temperatures |
| spellingShingle | Juan Enrique Martínez-Martínez Felipe Pedro Álvarez Rabanal Mariano Lázaro Mar Alonso-Martínez Daniel Alvear Juan José del Coz-Díaz Assessment of Lightweight Concrete Thermal Properties at Elevated Temperatures Applied Sciences lightweight concrete thermal conductivity specific heat elevated temperatures |
| title | Assessment of Lightweight Concrete Thermal Properties at Elevated Temperatures |
| title_full | Assessment of Lightweight Concrete Thermal Properties at Elevated Temperatures |
| title_fullStr | Assessment of Lightweight Concrete Thermal Properties at Elevated Temperatures |
| title_full_unstemmed | Assessment of Lightweight Concrete Thermal Properties at Elevated Temperatures |
| title_short | Assessment of Lightweight Concrete Thermal Properties at Elevated Temperatures |
| title_sort | assessment of lightweight concrete thermal properties at elevated temperatures |
| topic | lightweight concrete thermal conductivity specific heat elevated temperatures |
| url | https://www.mdpi.com/2076-3417/11/21/10023 |
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