## 5 Studies on Using other Types of PMC in Concrete for Thermal Energy Storage
Multiple scales of analysis were performed. The latent heat related to various phase-change materials was effectively incorporated into the framework of the simulation. Furthermore, continuum damage mechanics was used in the numerical simulations of the framework for assessing the impact of PCMs upon freeze-thaw-induced concrete damage. The incorporation of PCMs into concrete was shown in simulations to significantly reduce freeze-thaw-caused damage. The numerical simulation framework was used to efficiently optimise the composition and microstructure of such long-lasting PCM-incorporated concretes for pavements. To learn more about how to use the heat stored in PCMs to delay or avoid ice formation in concrete, [PERSON] et al. (2019) [85] looked into the manufacture and evaluation of mortar-PCM systems. After considering their thermal and physical qualities, desirable PCMs and light-weight aggregates (LWA), which carry the PCMs, were chosen. Multiple LWA formulations, including PCMs, were made and evaluated. The findings showed that when the LWA-PCMs were coated in a certain fashion, chemical processes or significant losses in latent heat were not necessary for the steady absorption of PCMs in LWAs. Exothermic/endothermic processes linked with phase changes of the pore solution and PCM confirmed the PCM's capacity to postpone or prevent ice formation in mortar. Furthermore, as shown in Figure 10, when up to 50% vol. of the LWA was substituted as carriers of PCM, the PCM produced enough heat to prevent ice formation. Figure 9: Specim temperature change rates during phase transition (solidification) [82]. To examine how seasonal changes, human comfort temperature, and wall design influence the thermal performance of a single-family home outfitted with multilayer walls containing PCMs in the climate conditions of Oslo (Norway), [PERSON] et al. (2019) [PERSON] et al. (2019) created a numerical model depending upon the technique of Finite Differences. Given their relative neglect in the past, the effects of adding insulation and varying the anticipated human comfort temperature were given special consideration. Microencapsulated phase change materials (MPCM) integrated into geopolymer concrete and pure phase change materials (PCM) added to multilayer walls were shown to greatly increase thermal performance. A yearly energy savings of 28-30% was achieved under ideal circumstances (a thick PCM layer and a thin insulating layer). It was discovered that PCM performed better when placed in a more natural setting. The energy needed to run a heating and cooling system may be drastically cut down by increasing the thickness of the insulating layer and decreasing its thermal conductivity. However, this has the unintended consequence of making the MPCM/PCM less efficient at using its high heat storage capacity. The multilayer walls performed best in the summer, with a decrease in energy use of up to 32% at temperatures below the bottom limit of the accepted human comfort zone (18 \({}^{\circ}\)C). [PERSON] et al. (2019) [PERSON] et al. (2019) introduced a straightforward computational model based on lumped capacitance. The algorithm enables a time-dependent thermal and energetic study of concrete TESs. ENEA (the Italian National Agency for New Technologies, Energy, and Sustainable Economic Development) conducted experiments with two distinct concrete mixes while heating and cooling them using mineral oil as the working fluid, and those results were used to verify the accuracy of the new simulation code. Furthermore, two distinct TES thermal efficiencies were provided based on the energetic analysis to assess the charge or discharge development over time. This straightforward model can drastically cut the amount of time spent simulating the TES, and it can be readily integrated into the simulation models of any concentrated solar power plant (CSP) and associated energy conversion plant for rapid assessment of the entire system's efficiency.