{"id":1042,"date":"2023-08-30T18:03:27","date_gmt":"2023-08-30T22:03:27","guid":{"rendered":"https:\/\/research.coe.drexel.edu\/caee\/aim\/?page_id=1042"},"modified":"2023-09-03T16:20:32","modified_gmt":"2023-09-03T20:20:32","slug":"pcm-con","status":"publish","type":"page","link":"https:\/\/research.coe.drexel.edu\/caee\/aim\/research\/pcm-con\/","title":{"rendered":"Phase Change Self-Thermal Responsive Concrete"},"content":{"rendered":"\n
\n
\n

Investigating Temperature Change Rate and Pore Confinement Effect of Thermal Properties of Phase Change Materials for De-icing and Low-temperature Applications in Cementitious Composites<\/strong><\/strong><\/h4>\n\n\n\n

Incorporation techniques of phase change materials (PCM) in cementitious composites have a significant influence on thermal properties. This study investigated the thermal behavior of low-temperature PCM when subjected to varying temperature change rates and pore confinement inside the porous network of lightweight aggregates (LWA) and encapsulation using melamine-formaldehyde-based polymer. Three categories of thermal energy storage (TES) specimens were prepared: (i) Bulk PCM (i.e., liquid PCM), (ii) micro-encapsulated PCM (MPCM), and (iii) four different LWAs infused with PCM (PCM-LWA). The thermal properties of small-scale individual TES specimens were analyzed using a low-temperature differential scanning calorimeter (LT-DSC) to evaluate the effect of ramp rates. Dynamic vapor sorption (DVS) analysis was utilized to characterize the pore structure of LWAs. LT-DSC results show that undercooling of the PCM significantly increases with the rise in ramp rate for all the specimens; the temperature change rate affects the nucleation and crystallization growth process during the phase transition. Pore structure characterization of LWAs indicates that the majority of the pores (> 92 %) were larger than 17.3 nm (i.e., macropores). Confined liquid properties are subjected to modification due to interaction with the confining surfaces, as explained by Gibbs-Thomson’s theory. PCM incorporated in the LWA porous network experienced variable degrees of supercooling during phase transition; the magnitude of confinement pressure is dependent on the pore diameter, structure, and tortuosity. Experimental evidence suggested that PCM-LWA will exhibit gradual expulsion of enthalpy of fusion over a larger temperature range\u00a0(i.e., ~-5 oC to 4.28 oC) in comparison to MPCM (i.e., ~4.28 oC).Incorporation techniques of phase change materials (PCM) in cementitious composites have a significant influence on thermal properties. This study investigated the thermal behavior of low-temperature PCM when subjected to varying temperature change rates and pore confinement inside the porous network of lightweight aggregates (LWA) and encapsulation using melamine-formaldehyde-based polymer. Three categories of thermal energy storage (TES) specimens were prepared: (i) Bulk PCM (i.e., liquid PCM), (ii) micro-encapsulated PCM (MPCM), and (iii) four different LWAs infused with PCM (PCM-LWA). The thermal properties of small-scale individual TES specimens were analyzed using a low-temperature differential scanning calorimeter (LT-DSC) to evaluate the effect of ramp rates. Dynamic vapor sorption (DVS) analysis was utilized to characterize the pore structure of LWAs. LT-DSC results show that undercooling of the PCM significantly increases with the rise in ramp rate for all the specimens; the temperature change rate affects the nucleation and crystallization growth process during the phase transition. Pore structure characterization of LWAs indicates that the majority of the pores (> 92 %) were larger than 17.3 nm (i.e., macropores). Confined liquid properties are subjected to modification due to interaction with the confining surfaces, as explained by Gibbs-Thomson’s theory. PCM incorporated in the LWA porous network experienced variable degrees of supercooling during phase transition; the magnitude of confinement pressure is dependent on the pore diameter, structure, and tortuosity. Experimental evidence suggested that PCM-LWA will exhibit gradual expulsion of enthalpy of fusion over a larger temperature range\u00a0(i.e., ~-5 oC to 4.28 oC) in comparison to MPCM (i.e., ~4.28 oC).<\/p>\n\n\n\n

View Full Paper<\/strong><\/strong><\/h5>\n<\/div>\n\n\n\n
\n
\"\"<\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n
<\/div>\n\n\n\n
\n
\n
\"\"<\/figure>\n<\/div><\/div>\n\n\n\n
\n

Development of Self-Heating Concrete using Low-Temperature Phase Change Materials: Multi-scale and In-situ Real-Time Evaluation of\u00a0 Snow-Melting and Freeze-thaw Performance<\/h4>\n\n\n\n

This work examined the performance of self-heating concrete under laboratory thermal conditions and outdoor real-time conditions during the fall and winter seasons. Snow melting<\/p>\n\n\n\n

and freeze-thaw performance of low-temperature phase change materials (PCM) incorporated self-heating concrete slabs in various scales were evaluated. PCM exhibited high enthalpy of fusion (\u0394Hf \u2248 170-180 J\/g), long-term thermal stability, and desirable supercooling. The experimental program includes: (i) optimization of concrete mix designs for maximum PCM incorporation, (ii) characterization of thermal properties of PCM-mortar specimens using longitudinal guarded comparative calorimetry (LGCC), and (iii) large-scale PCM concrete slabs in outdoor conditions to evaluate the real-time thermal performance against freeze-thaw events and snow-melting efficiency. Two different approaches were used to incorporate PCM in concrete: (i) submersion of liquid PCM in porous lightweight aggregates (PCM-LWA) and (ii) micro-encapsulated PCM (MPCM). Both PCM-LWA and MPCM concrete not only exhibit promising snow melting capabilities but also lowered the number of freeze-thaw cycles during cold seasons. PCM-LWA concrete performed better in decreasing the number of freeze-thaw (F-T) cycles due to the undercooling phenomenon created by the LWA pore network confinement pressure, allowing gradual latent heat release; the undercooling phenomenon in PCM-LWA results in phase transformation in a wider low-temperature range (i.e., 3.94 oC to -13.04 oC). Therefore, the PCM-LWA concrete was effective in melting snow within a wider range of low temperatures. MPCM concrete was found to provide a rapid melting capability during a snowfall event due to its \u2018one-shot\u2019 heat release phenomenon. Both LWA-PCM and MPCM concrete slabs demonstrate promising heat response and snow melting capability.<\/p>\n\n\n\n

View Full Paper<\/strong><\/strong><\/h5>\n<\/div>\n<\/div>\n\n\n\n
<\/div>\n","protected":false},"excerpt":{"rendered":"

Investigating Temperature Change Rate and Pore Confinement Effect of Thermal Properties of Phase Change Materials for De-icing and Low-temperature Applications in Cementitious Composites Incorporation techniques of phase change materials (PCM) in cementitious composites have a significant influence on thermal properties. This study investigated the thermal behavior of low-temperature PCM when subjected to varying temperature change…<\/span><\/p>\n

Read More<\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"parent":476,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1042","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/pages\/1042","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/comments?post=1042"}],"version-history":[{"count":5,"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/pages\/1042\/revisions"}],"predecessor-version":[{"id":1198,"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/pages\/1042\/revisions\/1198"}],"up":[{"embeddable":true,"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/pages\/476"}],"wp:attachment":[{"href":"https:\/\/research.coe.drexel.edu\/caee\/aim\/wp-json\/wp\/v2\/media?parent=1042"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}