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Thermo-physical and mechanical investigation of cementitious composites enhanced with microencapsulated phase change materials for thermal energy storage
Highlights Thermal Energy Storage (TES) of cement pastes enhanced with hydrophobic MPCMs is investigated. Three water-to-binder ratios (0.33, 0.40 and 0.45) and MPCM volume substitutions of 0%, 20% and 40%, were analyzed. Volumetric latent enthalpy was 20–25 MJ/m3 for paste samples with 20% MPCM and 55–60 MJ/m3 for 40% MPCM, independently of the w/b ratio. Thermal conductivity values measured at 25 and 45 °C ranged between 0.93 and 0.44 W/m × K. Comprehensive thermal, physical and mechanical tests were also performed.
Abstract This paper reports a comprehensive experimental investigation of cement pastes enhanced with Microencapsulated Phase Change Materials (MPCM) for Thermal Energy Storage (TES) purposes. The experimental plan considers three water-to-binder ratios and three MPCM volume fractions, for a total of nine different MPCM paste mixtures. The water-to-binder ratios of the pastes are 0.33, 0.40 and 0.45, which were mixed with a commercial MPCM, namely Nextek 37D® having a melting/solidification temperature of 37 °C, with volume percentage substitutions of 0%, 20% and 40%, respectively. Thermal, physical and mechanical tests were performed to investigate the effect MPCM have on the resulting TES, strengths and conductive properties of the considered mixtures by employing DSC, Hot-Disk, and mechanical tests. The measured latent heat of MPCM was 197.3 J/g and 194.6 J/g for heating and cooling, respectively. The volumetric latent enthalpies for the MPCM-based composites showed an almost constant average of 20–25 MJ/m3 for samples with 20% MPCM and 55–60 MJ/m3 for samples with 40% MPCM, independently of the w/b ratio. Thermal conductivity values measured at 25 and 45 °C ranged between 0.93 and 0.44 W/m × K. MPCM substitution turned out to significantly affect the overall porosity of the composite resulting in a lower thermal conductivity for the MPCM-pastes in comparison to the plain cement matrix. Finally, mechanical tests were conducted that showed a strength loss due to either increasing w/b ratios or for enhanced amounts of MPCM (e.g., up to a 74% and 69% of strength loss were registered for bending and compression, respectively). The thermo-physical and mechanical characterizations were conducted according to an experimental plan that provided a wide set of research results for both sole MPCM and MPCM-cement systems analyzed by SEM, EDS/elemental mapping, contact angle tests, particle size distribution analysis and Mercury Intrusion Porosimetry technique.
Thermo-physical and mechanical investigation of cementitious composites enhanced with microencapsulated phase change materials for thermal energy storage
Highlights Thermal Energy Storage (TES) of cement pastes enhanced with hydrophobic MPCMs is investigated. Three water-to-binder ratios (0.33, 0.40 and 0.45) and MPCM volume substitutions of 0%, 20% and 40%, were analyzed. Volumetric latent enthalpy was 20–25 MJ/m3 for paste samples with 20% MPCM and 55–60 MJ/m3 for 40% MPCM, independently of the w/b ratio. Thermal conductivity values measured at 25 and 45 °C ranged between 0.93 and 0.44 W/m × K. Comprehensive thermal, physical and mechanical tests were also performed.
Abstract This paper reports a comprehensive experimental investigation of cement pastes enhanced with Microencapsulated Phase Change Materials (MPCM) for Thermal Energy Storage (TES) purposes. The experimental plan considers three water-to-binder ratios and three MPCM volume fractions, for a total of nine different MPCM paste mixtures. The water-to-binder ratios of the pastes are 0.33, 0.40 and 0.45, which were mixed with a commercial MPCM, namely Nextek 37D® having a melting/solidification temperature of 37 °C, with volume percentage substitutions of 0%, 20% and 40%, respectively. Thermal, physical and mechanical tests were performed to investigate the effect MPCM have on the resulting TES, strengths and conductive properties of the considered mixtures by employing DSC, Hot-Disk, and mechanical tests. The measured latent heat of MPCM was 197.3 J/g and 194.6 J/g for heating and cooling, respectively. The volumetric latent enthalpies for the MPCM-based composites showed an almost constant average of 20–25 MJ/m3 for samples with 20% MPCM and 55–60 MJ/m3 for samples with 40% MPCM, independently of the w/b ratio. Thermal conductivity values measured at 25 and 45 °C ranged between 0.93 and 0.44 W/m × K. MPCM substitution turned out to significantly affect the overall porosity of the composite resulting in a lower thermal conductivity for the MPCM-pastes in comparison to the plain cement matrix. Finally, mechanical tests were conducted that showed a strength loss due to either increasing w/b ratios or for enhanced amounts of MPCM (e.g., up to a 74% and 69% of strength loss were registered for bending and compression, respectively). The thermo-physical and mechanical characterizations were conducted according to an experimental plan that provided a wide set of research results for both sole MPCM and MPCM-cement systems analyzed by SEM, EDS/elemental mapping, contact angle tests, particle size distribution analysis and Mercury Intrusion Porosimetry technique.
Thermo-physical and mechanical investigation of cementitious composites enhanced with microencapsulated phase change materials for thermal energy storage
Sam, Mona (author) / Caggiano, Antonio (author) / Dubyey, Liliya (author) / Dauvergne, Jean-Luc (author) / Koenders, Eddie (author)
2022-04-18
Article (Journal)
Electronic Resource
English