TY - JOUR
T1 - Porous inclusions as hosts for phase change materials in cementitious composites
T2 - Characterization, thermal performance, and analytical models
AU - Aguayo, Matthew
AU - Das, Sumanta
AU - Castro, Cesar
AU - Kabay, Nihat
AU - Sant, Gaurav
AU - Neithalath, Narayanan
N1 - Publisher Copyright:
© 2016 Elsevier Ltd
PY - 2017/3/1
Y1 - 2017/3/1
N2 - This paper examines the influence of four different porous hosts (lightweight aggregates (LWA)) having different pore structure features, as hosts for phase change materials (PCM). The porosity and absorption capacity of the LWAs significantly influence the composite thermal conductivity. The incorporation of 5% of PCMs by total volume of the cementitious system reduces the composite thermal conductivity by ⩾10%. The fact that the inclusions (LWAs) in these composites are by themselves heterogeneous, and contain multiple components (solid phase, PCM, water, and air) necessitate careful application of predictive models. Multi-step Mori-Tanaka mean-field homogenization methods, either based on known microstructural arrangement in the composite, or property contrast between the constituents, are applied to predict the composite thermal conductivity. A microstructural contrast factor is used to account for both the thermal conductivities and the volume fractions of the phases with the highest property contrast. Smaller contrast factors result in improved agreement of the models with the experiments, thereby aiding in the selection of suitable predictive schemes for effective properties of such multi-phase composites.
AB - This paper examines the influence of four different porous hosts (lightweight aggregates (LWA)) having different pore structure features, as hosts for phase change materials (PCM). The porosity and absorption capacity of the LWAs significantly influence the composite thermal conductivity. The incorporation of 5% of PCMs by total volume of the cementitious system reduces the composite thermal conductivity by ⩾10%. The fact that the inclusions (LWAs) in these composites are by themselves heterogeneous, and contain multiple components (solid phase, PCM, water, and air) necessitate careful application of predictive models. Multi-step Mori-Tanaka mean-field homogenization methods, either based on known microstructural arrangement in the composite, or property contrast between the constituents, are applied to predict the composite thermal conductivity. A microstructural contrast factor is used to account for both the thermal conductivities and the volume fractions of the phases with the highest property contrast. Smaller contrast factors result in improved agreement of the models with the experiments, thereby aiding in the selection of suitable predictive schemes for effective properties of such multi-phase composites.
KW - Homogenization models
KW - Lightweight aggregate
KW - Microstructure
KW - Phase change materials (PCM)
KW - Thermal conductivity
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U2 - 10.1016/j.conbuildmat.2016.12.185
DO - 10.1016/j.conbuildmat.2016.12.185
M3 - Article
AN - SCOPUS:85008186494
SN - 0950-0618
VL - 134
SP - 574
EP - 584
JO - Construction and Building Materials
JF - Construction and Building Materials
ER -