Defensive behaviour of building envelopes in terms of mechanical and thermal responsiveness by incorporating PCMs in cement mortar layers

Kontoleon, Karolos J.; Stefanidou, Maria; Shaik, Saboor; Mazzeo, Domenico; Karaoulis, A.; Zegginis, D.; Kraniotis, Dimitrios

doi:10.1016/j.seta.2021.101349

Cited by 8 publications

(3 citation statements)

References 47 publications

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“…As expected, an important decrease in mechanical properties is generally observed as a consequence of the introduction of a PCM, irrespective to the kind of PEG composing the PCM. This behavior has been observed in several other studies; with the inclusion of PCM, the mechanical properties of mortars can significantly decrease [ 23 , 38 , 39 ]. Several reasons may explain this occurrence: (i) An increase in the porosity of the mortar containing the PCM; (ii) a delay of the hydration reaction of the mortar; and (iii) in the case of a form-stable PCM, as in the present study, the polymeric component that constitutes the PCM, a part of which can be located on the surface of the inert support, can take part in the mixing of the mortar, reducing its mechanical properties.…”

Section: Resultssupporting

confidence: 81%

“…This behavior could be attributed to small portions of the PEG800 polymer possessing a low viscosity at room temperature [ 27 ], with portions lying on the surface of the Lecce Stone grains that can contribute to improving the workability of the mortar mix with replacement of a limited amount of the required water. This feature can, nevertheless, represent an important advantage, potentially counteracting the detrimental effects on mechanical properties brought about by the addition of a PCM in the mortars, as previously reported [ 26 , 37 , 38 , 39 ].…”

Section: Resultsmentioning

confidence: 62%

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Physical Properties of Eco-Sustainable Form-Stable Phase Change Materials Included in Mortars Suitable for Buildings Located in Different Continental Regions

2022

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Starting from two low-cost, low-environmental-impact polymers belonging to the Polyethylene Glycol (PEG) family, i.e., PEG 800 and PEG 1000, two form-stable phase change materials were produced. The two PEGs differ in molecular weight and, as a consequence, the melting and crystallization range of temperatures. The PCMs were obtained, including the PEG, in a liquid state, inside the pores of Lecce Stone flakes, obtained as waste pieces from its processing. A simple and inexpensive impregnation process was selected to produce the PCMs, thus adopting low-environmental-impact materials and cheap processes, and respecting circular economy principles. The two PCMs, the first composed of PEG 800, namely LS/PEG800, and the second composed of a 50/50%wt. mix of the different LS/PEGs, i.e., LS/PEG800_LS/PEG1000, were added as aggregates to four types of mortars, based on aerial and hydraulic lime, gypsum, and cement. The obtained mortars were characterized in their fresh state to assess their workability, and in a solid state after a proper cure to determine their characteristic Latent Heat Thermal Energy Storage (LHTES) properties and mechanical properties in both flexural and compressive modes, taking the mortars not containing any PCM as the reference. The results revealed that, with the proper selection of mortar formulations, it was possible to achieve suitable workability and adequate mechanical characteristics. The selection of a PEG with a low range of phase change temperatures, such as PEG 800, allows one to obtain mortars characterized by a melting/crystallization range that can be considered appropriate in applications characterized by cold climates. The production of a mixed PCM, composed of both PEGs, led to mortars displaying a large interval of melting/crystallization temperatures, which could be suitable in both warm and cold climates.

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Section: Resultssupporting

confidence: 81%

Section: Resultsmentioning

confidence: 62%

Physical Properties of Eco-Sustainable Form-Stable Phase Change Materials Included in Mortars Suitable for Buildings Located in Different Continental Regions

2022

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“…The combination of PCM with other materials, such as cement mortar [30], bricks [31,32], concrete [33], diatomite [34], etc., has been extensively studied. However, these studies have only focused on the thermal performance of the combined envelope.…”

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confidence: 99%

Simulation of the Hygrothermal Behavior of a Building Envelope Based on Phase Change Materials and a Bio-Based Concrete

Wu¹,

Rahim²,

Li³

et al. 2022

Fluid Dynamics &Amp; Materials Processing

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Phase Change Materials (PCMs) have high thermal inertia, and hemp concrete (HC), a bio-based concrete, has strong hygroscopic behavior. In previous studies, PCM has been extensively combined with many materials, however, most of these studies focused on thermal properties while neglecting hygroscopic aspects. In this study, the two materials have been combined into a building envelope and the related hygrothermal properties have been studied. In particular, numerical studies have been performed to investigate the temperature and relative humidity behavior inside the HC, and the effect of adding PCM on the hygrothermal behavior of the HC. The results show that there is a high coupling between temperature and relative humidity inside the HC, since the relative humidity changes on the second and third days are different, with values of 8% and 4%, respectively. Also, the variation of relative humidity with temperature indicates the dominant influence of temperature on relative humidity variation. With the presence of PCM, the temperature variation inside the HC is damped due to the high thermal inertia of the PCM, which also leads to suppression of moisture evaporation and thus damping of relative humidity variation. On the second and third days, the temperature changes at the central position are reduced by 4.6% and 5.1%, compared to the quarter position. For the relative humidity change, the reductions are 5.3% and 5.4% on the second and third days, respectively. Therefore, PCM, with high thermal inertia, acts as a temperature damper and has the potential to increase the moisture buffering capacity inside the HC. This makes it possible for such a combined envelope to have both thermal and hygric inertia. KEYWORDSPhase change material (PCM); bio-based concrete; passive building envelope; heat and moisture transfer; hygrothermal performance Nomenclature C hc heat capacity of HC (J/(kg•K)) C Ã effective specific heat capacity of PCM (J/(kg•K)) K w liquid water permeability (kg/(Pa•m•s)) L v heat of vaporization (J/kg) M w molar mass of water (kg/mol) p v,sat saturation pressure (Pa) q stisosteric heat (J/kg)

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Numerical analysis on phase change progress and thermal performance of different roofs integrated with phase change material (PCM) in Moroccan semi-arid and Mediterranean climates

Huang

Yang²,

Aadmi³

et al. 2022

Build. Simul.

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Defensive behaviour of building envelopes in terms of mechanical and thermal responsiveness by incorporating PCMs in cement mortar layers

Cited by 8 publications

References 47 publications

Physical Properties of Eco-Sustainable Form-Stable Phase Change Materials Included in Mortars Suitable for Buildings Located in Different Continental Regions

Physical Properties of Eco-Sustainable Form-Stable Phase Change Materials Included in Mortars Suitable for Buildings Located in Different Continental Regions

Simulation of the Hygrothermal Behavior of a Building Envelope Based on Phase Change Materials and a Bio-Based Concrete

Numerical analysis on phase change progress and thermal performance of different roofs integrated with phase change material (PCM) in Moroccan semi-arid and Mediterranean climates

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