Assessment of lightweight concrete thermal properties at elevated temperatures
| Autor: | Mariano Lázaro, Juan J. del Coz-Díaz, Juan Enrique Martínez-Martínez, Felipe Pedro Álvarez Rabanal, Daniel Alvear, Mar Alonso-Martínez |
|---|---|
| Přispěvatelé: | Universidad de Cantabria |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Technology
Materials science QH301-705.5 QC1-999 Endothermic process Laser flash analysis Lightweight concrete Differential scanning calorimetry Thermal conductivity Thermal insulation Thermal General Materials Science thermal conductivity Composite material Biology (General) Porosity Instrumentation Water content QD1-999 Fluid Flow and Transfer Processes business.industry Process Chemistry and Technology Physics General Engineering lightweight concrete Engineering (General). Civil engineering (General) Computer Science Applications Chemistry specific heat Specific heat TA1-2040 business elevated temperatures Elevated temperatures |
| Zdroj: | Scopus Applied Sciences Volume 11 Issue 21 Applied Sciences, 2021, 11(21), 10023 RUO. Repositorio Institucional de la Universidad de Oviedo instname Applied Sciences, Vol 11, Iss 10023, p 10023 (2021) UCrea Repositorio Abierto de la Universidad de Cantabria Universidad de Cantabria (UC) |
| Popis: | 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. This research was funded by FICYT and the Spanish Ministry of Science, Innovation, and Universities, co-financed with FEDER funds under the Research Projects PGC2018-098459-B-I00 and FC-GRUPIN-IDI/2018/000221. Finally, the authors would like to thank the Consejo de Seguridad Nuclear for the cooperation and co-financing the project “Metodologías avanzadas de análisis y simulación de escenarios de incendios en centrales nucleares”. |
| Databáze: | OpenAIRE |
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