Mechanical, thermal, and fire properties of composite materials based on gypsum and PCM

  Citation: Stejskalová, K.; Bujdoš, D.; Procházka, L.; Smetana, B.; Zlá, S.; Teslík, J. Mechanical, Thermal, and Fire Properties of Composite Materials Based on Gypsum and PCM. Materials 2022,15, 1253. https://doi.org/10.3390/ma15031253 Academic Editors: Marijana Hadzima-Nyarko and Paola Palmero Received: 13 December 2021 Accepted: 6 February 2022 Published: 8 February 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). materials Article Mechanical, Thermal, and Fire Properties of Composite Materials Based on Gypsum and PCM Kateˇrina Stejskalová1,* , David Bujdoš 1, Lukáš Procházka 1, Bedˇrich Smetana 2, Simona Zlá2and JiˇríTeslík1 1Faculty of Civil Engineering, VSB—Technical University of Ostrava, 70800 Ostrava, Czech Republic; [email protected] (D.B.); [email protected] (L.P.); [email protected] (J.T.) 2Faculty of Materials Science and Technology, VSB—Technical University of Ostrava, 70800 Ostrava, Czech Republic; [email protected] (B.S.); [email protected] (S.Z.) *Correspondence: [email protected] Abstract: One of the solutions for overheating the interior in the summer without increasing energy consumption is the integration of phase change material (PCM) into interior plasters. However, adding PCM to plasters deteriorates their properties and thus their usability. The aim of this paper is to determine how the microencapsulated PCM affects the mechanical, thermal, and fire properties of plasters and how much PCM can be added to the plaster. Two sets of samples were prepared: in set S, part of the aggregate was replaced by PCM; and in set R, only PCM was added. The bulk density, flexural strength, compressive strength, tensile strength perpendicular to the surface, thermal conductivity coefficient, specific heat capacity, melting, and solidification temperatures and enthalpy were measured. A single-flame source fire test and a gross heat of combustion fire test were performed to determine the reaction to the fire class. The results show that with an increasing proportion of PCM, the strength of the samples of set R decreased more significantly than it did with the samples of set S. It was found that only up to about 10% PCM could be added to set R, while up to 30% PCM could be added to set S. Keywords: fire properties; gypsum; mechanical properties; phase change material; thermal properties 1. Introduction Overheating of rooms in the summer months is a common problem, especially when using lightweight structures. Recently, more attention has been paid to this topic; it is necessary to find a long-term effective solution to this problem. With the right design, it is possible to reduce interior overheating in the summer months to ensure thermal comfort for the occupants. The simplest solution is the use of air conditioning, but its energy consumption during operation has a negative impact on the environment. One solution without the need for power consumption for operation is the use of phase change material (PCM) [ 1 ]. PCM is able to store/release latent heat at normal indoor air temperatures [ 2 , 3 ]. When the temperature in the interior reaches the melting temperature of the material, a phase change (melting) occurs in the material, during which energy is stored in the form of latent heat [ 4 ]. The heat storage in the PCM reduces the indoor temperature. Conversely, when the indoor air temperature drops below the solidification temperature, the material solidifies back and releases heat into the interior. This increases the temperature in the interior and saves energy required for heating. There are several ways to integrate PCM into a building’s structure [ 5 , 6 ]; this paper focuses on the integration of PCM into interior plasters [7]. Although the integration of PCM into plaster mixtures will increase the heat storage capacity, it might worsen the mechanical properties, thermal conductivity [ 8 – 12 ], and fire resistance of the plaster [ 13 – 16 ]. The aim of this research is to get as much PCM as possible into the plaster mixture, but at the same time meet the requirements for the usability, strength, and fire resistance of the plaster [ 17 , 18 ]. There are many materials used Materials 2022,15, 1253. https://doi.org/10.3390/ma15031253 https://www.mdpi.com/journal/materials Materials 2022,15, 1253 2 of 17 as PCM [ 4 ]; microencapsulated PCM was used in this research. Zhuk [ 19 ] found in a lifecycle analysis that gypsum plaster with microencapsulated PCM could withstand over 10,000 temperature load cycles without losing its properties, which corresponds to more than 30 years of minimal service life according to RAL-GZ 896 [ 20 ]. PCM has the function of an aggregate in the mixture. However, due to its fine structure, it cannot completely replace the aggregate, so PCM forms only a part of the aggregate in the plaster mixture. The first option is to create completely new mixtures, in which a part of the aggregate is replaced by PCM [ 21 – 23 ], and the second option is to add PCM to the commercial dry plaster mixture [ 24 – 26 ]. In the second option, it is not possible to get too much PCM into the plaster, because its addition increases the amount of aggregate in the mixture, but it is very easy to prepare such a plaster on the construction site. In this paper, both possibilities of creating a plaster mixture were tested and compared. Several research groups have investigated the mechanical and thermal properties of PCM plasters [ 27 ]. Bajare et al. [ 8 ] found that adding 10% microencapsulated PCM to a cement–lime plaster reduced its flexural strength by 40% and its compressive strength by 60%. Pavlík et al. [ 9 ] added 8%, 16%, and 24% PCM to a commercial plaster mixture and investigated the basic physical, mechanical, and thermal properties. The additional phase change enthalpy was up to 13 J/g, but the mechanical parameters decreased by up to 40%, which means that the plasters did not meet the requirements of the standard [ 17 ]. Foˇrt et al. [ 24 ] presented similar research with 4%, 8%, and 12% PCM in a commercial plaster mixture. Based on previous research, Foˇrt et al. [ 28 ] evaluated the designed plasters by computational analysis. Klimeš et al. [ 29 ] developed an optimization model of a thermally activated wall system with a gypsum plaster containing a microencapsulated PCM. Pavlík et al. [ 21 ] presented the results of a DSC analysis (melting and crystallization peak temperature and heat) of lime–pozzolan plaster with 5%, 10%, and 15% of PCM. DSC analysis of lime–pozzolan plaster with 5% was also performed by Pavlíkováet al. [ 30 ]. Kusama et al. [ 23 ] performed a laboratory and residential-scale test of the PCM gypsum plaster. The PCM plaster offered a high solar radiation effective utilization rate (82%). Zhou et al. [31] numerically evaluated a PCM–gypsum composite in a passive solar building in Beijing with an enthalpy model. The PCM–gypsum composite effectively shaved the indoor temperature swing by 46%. Theodoridou et al. [ 32 ] added 5% PCM into plasters with hydrated lime or hydraulic lime and investigated their thermal, physical, and mechanical properties. The plasters with hydrated lime did not meet the requirements of the standard [ 17 ]. Kheradmand et al. [ 33 ] compared a modified cement plaster containing 18.34% PCM to a reference plaster. Compared to the reference plaster without PCM, a 20% reduction in energy consumption for heating/cooling was found. Kusama et al. [ 34 ] evaluated the basic thermal performance and energy-saving effects of a system containing a PCM plaster. The thermal energy-saving effects in Hokkaido, Japan were approximately 52%. Carbonaro et al. [ 35 ] added 14% PCM with melting temperatures of 26 ◦ C (V1) and 23 ◦ C (V2) into a plaster based on lime and gypsum. The thermal conductivities at 6, 21, and 36 ◦ C was measured: for the plaster with PCM V1, there was a reduction of 68%; and for PCM V2 there was a reduction of 47%. To improve the thermal conductivity of a plaster, it is possible to add natural or expanded graphite [ 22 ] or aluminum [ 36 ] to the mixture. To increase the heat storage/release, plasters can be impregnated with PCM [ 37 – 39 ]. Several studies have also focused on the fire properties of building materials containing PCM. Some have researched plasterboards [ 14 , 40 ], and others have researched plasters [ 15 , 41 ]. Using new types of PCM [ 42 , 43 ], improved coatings [ 41 ], or bio-PCM [ 40 ], it is possible to increase the fire resistance of a structure. To determine the usability of a plaster in the interior, the reaction to fire class is also important, which this paper will extend beyond the mentioned research. In this research, the PCM Micronal DS 5008 X (manufactured by BASF SE, Ludwigshafen, Germany) was selected. It is a fine powder consisting of paraffin wax encapsulated in polymeric spherical microcapsules [ 44 ]. Gypsum, which is commonly used for interior plasters, was chosen as the binder [ 45 ]. Two sets of samples with an increasing proportion of PCM of approximately 5–10% were prepared. In the first set, part of the Materials 2022,15, 1253 3 of 17 aggregate was replaced by PCM, and in the second set, PCM was added to the commercial gypsum plaster mixture. The mechanical, thermal, and fire properties of these samples were determined. The aim of this research was to determine the dependence of individual properties on the amount of PCM in the plaster mixture so that it was possible to better predict how a given amount of PCM in a mixture will affect its properties [ 46 ]. From the mechanical properties, the flexural strength P F (MPa), the compressive strength R C (MPa), and the tensile strength perpendicular to the surface R u (MPa) were measured. From the thermal properties, the thermal conductivity coefficient and the specific heat capacity were measured. A DSC (differential scanning calorimetry) analysis determined the melting and solidification temperatures and latent heat of the developed composite material. From the fire properties, the reaction to fire class of the composite material was determined. Gypsum and aggregates are non-flammable materials of class A1 [ 47 ], but PCM is made of paraffin wax and polymer, which are highly flammable. Therefore, a single-flame source fire test and a gross heat of combustion fire test were used to determine how PCM degrades the fire resistance of the developed composite material and in which reaction to fire class according to [47] the composite material would be classified. This paper first describes the materials used and the process for producing individual gypsum plaster samples with different proportions of PCM. The next chapter describes methods for measuring individual mechanical, thermal, and fire properties. This is followed by a description and analysis of the results obtained by that measurement. Finally, the results of both sets are compared. 2. Materials and Methods 2.1. Materials Used For the production of the composite, gypsum, fine quartz sand (0.09–1.25 mm), commercial gypsum plaster mixture, and PCM were selected. PCM Micronal DS 5008 X was used in all test samples. Two sets of test samples with an increasing proportion of PCM were prepared. For the first set, gypsum (CaSO 4· 1/2 H 2 O) class G5 [ 48 ] was used as a binder and sand and PCM as aggregate. As the proportion of PCM in the mixture increased, the amount of sand decreased. This set was marked as S. The second set was made of commercial gypsum plaster mixture (Rigips Rimano UNI) and PCM. Rigips Rimano UNI plaster mixture contains gypsum with additives that improve application and adhesion, lime hydrate and lightweight expanded perlite [ 49 ]. This set was marked as R. The addition of PCM as aggregate to the commercial mixture increases the amount of aggregate in the composite, and therefore it was not possible to add as much PCM to this set as to set S. Samples S0 and R0 were reference and did not contain PCM. 2.2. Production Process A total of eight test samples were produced in set S and five samples in set R. First, the dry components of the mixture were weighed according to Tables 1and 2. The amount of PCM and sand was determined so that in each sample the ratio of aggregate volume to gypsum volume was the same as it was in reference samples S0 and R0. Mixtures of dry components and a sample containing only PCM were used for differential scanning calorimetry and gross heat of combustion measurement. To measure the other properties, water was gradually added in the amounts shown in Tables 1and 2. The mixture was mixed for about one minute. Materials 2022,15, 1253 4 of 17 Table 1. Mixture composition of the S set. Sample Gypsum (g) Water (g) Sand (g) PCM (g) PCM (%) S0 500 700 2000 0 0 S1 500 700 1200 190 10.1 S2 500 700 950 255 15.0 S3 500 700 660 300 20.5 S4 500 700 500 350 25.9 S5 500 700 350 400 32.0 S6 500 700 200 450 39.1 S7 500 700 0 500 50.0 Table 2. Mixture composition of the R set. Sample Gypsum Plaster (g) Water (g) PCM (g) PCM (%) R0 1000 600 0 0 R1 900 540 100 10 R2 800 480 200 20 R3 700 420 250 26 R4 700 420 300 30 To measure the tensile strength perpendicular to the surface, a layer of each plaster mixture was applied to the aerated concrete blocks (Figure 1). The surface of the aerated concrete blocks was penetrated and a layer of each plaster mixture approximately 20 mm thick was applied. These samples were left in the test environment (temperature 23 ± 2 ◦ C and relative air humidity 50 ±5%) for 28 days and then tested [50]. Figure 1. Samples to measure the tensile strength perpendicular to the surface. For the single-flame source fire test, samples measuring 250 × 90 × 15 mm were made [ 51 ]. First, a base measuring 250 × 90 mm and a form were made of 8 mm thick chipboard. These forms were filled with individual plaster mixtures, and the surface of the samples was smoothed with a trowel. These samples were stored in the test environment (temperature 23 ± 2 ◦ C and relative air humidity 50 ± 5%) for 28 days [ 50 ], then removed (Figure 2) and tested. Materials 2022,15, 1253 5 of 17 Figure 2. Sample for the single-flame source fire test. For other tests, samples with dimensions of 160 × 40 × 40 mm (Figure 3) were created by filling the plastic molds with a plaster mixture [ 50 ]. After the mold was filled, air was expelled from the samples, and the surfaces of the samples were smoothed. Due to the sizes of the samples and the presence of PCM, the samples still had high humidity after 28 days. The humidity of the samples for strength testing was measured by the gravimetric method, and the humidity of the samples applied to the aerated concrete blocks was determined with capacitive moisture measurement device GREISINGER GMK 100. While reference samples S0 and R0 had a humidity of about 5% and could be tested, samples with PCM had a humidity of 15% to 20%. PCM slowed the drying and setting of these larger samples. Therefore, the samples were stored in the test environment (temperature 23 ± 2 ◦ C and relative humidity of the air 50 ± 5%) for three months. Before testing, all samples were conditioned at 40 ◦C for 48 h, then left in the test environment for another 2 h. Figure 3. Samples from plastic molds. 2.3. Test Methods All samples were weighed and the dimensions of the samples removed from the molds were measured. The volume of these samples was calculated and their bulk density ρ (kg · m −3 ) was determined. All tests were carried out according to valid standards. The indoor air temperature and relative humidity during sample testing was 24 ◦ C and 45.0%, respectively. 2.3.1. Flexural Strength The samples were placed sideways in the FormTest press on supports spaced 100 mm apart. The longitudinal axis of the samples was perpendicular to the supports of the press. The load was transmitted through the load roller perpendicular to the sample surface. The load was evenly increased at 10 N/s until the sample broke (Figure 4). The force that caused the break of the sample was recorded. The flexural strength P F (MPa) was calculated according to Equation (1). PF=0.00234·P(1) where P(N) is the maximum applied load [50]. Materials 2022,15, 1253 6 of 17 Figure 4. Sample after the flexural strength test. 2.3.2. Compressive Strength The halves of the test samples broken in the flexural strength test were tested for compressive strength over an area of 40 × 40 mm. The samples were placed sideways on the FormTest press and centered relative to the press plates. The load was evenly increased at 50 N/s until the failure occurred in the samples (Figure 5) and the peak load was reached. The maximum force was recorded. The compressive strength R C (MPa) was calculated according to Equation (2). RC= FC 1600 (2) where Fc(N) is the maximum applied load [50]. Figure 5. Sample after the compressive strength test. 2.3.3. Tensile Strength Perpendicular to the Surface First, test cylinders with a diameter of 50 mm were drilled into the plaster layer. Drilling was carried out to a depth of 5 mm in the aerated concrete blocks. Circular steel targets were centrically glued to the surfaces of the cylinders with cyanoacrylate glue. The tensile load was applied perpendicular to the test surface over the circular targets using a Comtest OP3 test device (Figure 6). The load was evenly increased at 5 N/s until the sample was torn off. The maximum applied load and the way the sample was torn off were recorded. The tensile strength perpendicular to the surface R u (MPa) was calculated according to Equation (3). Ru= Fu A(3) where F u (N) is the maximum applied load and A(mm 2 ) is the test area of the cylindrical sample [50]. Materials 2022,15, 1253 7 of 17 Figure 6. Measurement of the tensile strength perpendicular to the surface. 2.3.4. Thermal Conductivity The thermal conductivity coefficient was measured with the ISOMET 2114 device equipped with a surface probe (Figure 7). The surface probe was placed sequentially on the surface of each sample. This device uses a non-stationary hot wire method for measurement [ 52 ]. The principle of this method is to record temperature rises and falls at a defined distance from the heat source, that is, the hot wire. The ISOMET 2114 device records the power per unit length, temperatures, and times and calculates the thermal conductivity coefficient λ(W·m−1·K−1) [53]. Figure 7. ISOMET device with the surface probe on the sample. 2.3.5. Specific Heat Capacity The specific heat capacity was also determined using an ISOMET 2114 device with a surface probe. The measuring principle is the same as that of the thermal conductivity measurements [ 52 ]. The device records the amount of heat per unit volume and changes in temperature and calculates the volumetric heat capacity C ρ (J · m −3· K −1 ) [ 53 ]. Based on the bulk density of individual samples, the specific heat capacity c(J · kg −1· K −1 ) was calculated according to Equation (4). c= Cρ ρ(4) where Cρ(J·m−3·K−1) is the volumetric heat capacity and ρ(kg·m−3) is the bulk density. 2.3.6. Differential Scanning Calorimetry DSC analysis was performed using a 3D DSC calorimeter Setaram SENSYS EVO in horizontal mode equipped with a unique 3D DSC sensor [ 54 ]. Absolute enthalpy calibration by use of Joule effect was performed. Temperature calibration was performed using high purity of In (5N). All the samples were cyclic analyzed. Heating and cooling followed by Materials 2022,15, 1253 8 of 17 second heating and cooling were performed at the rate of 2 ◦ C/min in He (6N) atmosphere. The powdery samples were analyzed in corundum “boats”. The masses of samples were between 50 and 147 mg. The enthalpy (heat effects) of melting and solidification of samples—PCM in prepared samples—were measured. The enthalpy is demonstrated by the peak areas (yellow areas) in Figures 8and 9. The first observed deviation (at 10 ◦ C) from the base line was taken as the start of the melting and the end of the peak (35 ◦ C) denotes the end of the melting process as presented on the DSC curve of pure PCM (Figure 8). The same procedure for peak area evaluation was used for the cooling process. The first observed deviation (at 21 ◦ C) from the base line was taken as the start of the solidification and the end of the peak (6 ◦ C) denotes the end of the solidification process as presented on the DSC curve of the pure PCM (Figure 9). Mean values of enthalpy of melting (from two heating runs) and solidification (from two cooling runs) were calculated. The mean values of start and end of melting and solidification were obtained. Figure 8. DSC curve of pure PCM, peak start and end temperature, and area of the peak (heat absorbed)—heating. Figure 9. DSC curve of pure PCM, peak start and end temperature, area of the peak (heat released)—cooling. 2.3.7. Single-Flame Source Fire Test The ignitability of samples subjected to direct impingement of flame was measured by a single-flame source test in a combustion chamber. Two horizontal axes were marked on the exposed surfaces of the samples. The first axis was 40 mm from the bottom edge of the sample. The second axis was at a distance of 150 mm from the first axis. The first axis determined where the flame of the gas burner touched the surface of the measured sample. The flame height was set at 20 mm, then the gas burner was tilted 45 ◦ with respect to the vertical axis (Figure 10). The samples were exposed to flame for 30 s. During the test, it was recorded whether ignition occurred and whether the flame front exceeded the second axis, as well as the time at which this occurred. The physical behavior of the test samples was Materials 2022,15, 1253 9 of 17 observed during the test [ 51 ]. First, the samples with the highest PCM proportion (S6, S7, and R4) were measured, and if these samples passed this test, the samples with the lower PCM proportion would also pass. Figure 10. Sample in the combustion chamber. 2.3.8. Gross Heat of Combustion The gross heat of combustion (calorific value) Q PCS (MJ · kg −1 ) was measured in an oxygen bomb calorimeter IKA C 200. The measurement was performed under standardized isoperibolic conditions, at constant volume, and in an oxygen atmosphere. The test sample was burned in a bomb calorimeter using the crucible method, and the gross heat of combustion was calculated on the basis of the observed temperature rise, taking into account the heat loss and the latent heat of water vaporization [ 55 ]. As gypsum and sand are non-flammable, only the gross heat of combustion of the pure PCM was measured (Figure 11). PCM is a fine powder; the sample was compressed with an IKA pelleting press prior to measurement. The mass of the samples was approximately 0.50 g. The gross heat of combustion of the other samples was calculated from the measured value according to the percentage of PCM in the mixture. Figure 11. Sample in the crucible of the bomb calorimeter. 3. Results and Discussion Each test was carried out according to standards for several samples. The average of the measured values was calculated. The average values of the quantities are given in Tables 3–6. Materials 2022,15, 1253 16 of 17 4. Cabeza, L.F.; Castell, A.; Barreneche, C.; De Gracia, A.; Fernández, A.I. Materials used as PCM in thermal energy storage in buildings: A review. Renew. Sustain. Energy Rev. 2011,15, 1675–1695. [CrossRef] 5. Cui, Y.; Xie, J.; Liu, J.; Pan, S. Review of Phase Change Materials Integrated in Building Walls for Energy Saving. Procedia Eng. 2015,121, 763–770. [CrossRef] 6. Konuklu, Y.; Ostry, M.; Paksoy, H.O.; Charvat, P. Review on using microencapsulated phase change materials (PCM) in building applications. Energy Build. 2015,106, 134–155. [CrossRef] 7. Al-Absi, Z.A.A.S.; Isa, M.H.M.; Ismail, M. Application of Phase Change Materials (PCMs) in Building Walls: A Review. In The Advances in Civil Engineering Materials; Awang, M., Isa, M., Eds.; ICACE 2018. Lecture Notes in Civil Engineering; Springer: Singapore, 2019; Volume 19. [CrossRef] 8. Bajare, D.; Kazjonovs, J.; Korjakins, A. Development of Latent Heat Storage Phase Change Material Containing Plaster. Mater. Sci. 2016,22, 94–97. [CrossRef] 9. Pavlík, Z.; Foˇrt, J.; Pavlíková, M.; Pokorný, J.; Trník, A.; ˇ Cerný, R. Modified lime-cement plasters with enhanced thermal and hygric storage capacity for moderation of interior climate. Energy Build. 2016,126, 113–127. [CrossRef] 10. Foˇrt, J.; Trník, A.; Pavlík, Z. Influence of the Heating and Cooling Rate on Thermal Performance of Cement-Lime Plaster with PCM Admixture. Key Eng. Mater. 2016,677, 150–154. [CrossRef] 11. Foˇrt, J.; Trník, A.; Pavlík, Z. Latent Heat Storage in Plasters with Incorporated PCM Water Dispersion. Mater. Sci. Forum 2015 ,824, 1–6. [CrossRef] 12. Foˇrt, J.; Novotný, R.; Trník, A.; ˇ Cerný, R. Preparation and Characterization of Novel Plaster with Improved Thermal Energy Storage Performance. Energies 2019,12, 3318. [CrossRef] 13. Gnanachelvam, S.; Ariyanayagam, A.; Mahendran, M. Fire resistance of light gauge steel framed wall systems lined with PCM-plasterboards. Fire Saf. J. 2019,108, 102838. [CrossRef] 14. Kolaitis, D.I.; Asimakopoulou, E.K.; Founti, M.A.; Vallerent, S.; Florence, C. Gypsum plasterboards enhanced with phase change materials: A fire safety assessment using experimental and computational techniques. MATEC Web Conf. 2013 ,9, 06002. [CrossRef] 15. Haurie, L.; Serrano, S.; Bosch, M.; Fernandez, A.I.; Cabeza, L.F. Single layer mortars with microencapsulated PCM: Study of physical and thermal properties, and fire behaviour. Energy Build. 2016,111, 393–400. [CrossRef] 16. Kontogeorgos, D.A.; Semitelos, G.K.; Mandilaras, I.D.; Founti, M.A. Experimental investigation of the fire resistance of multi-layer drywall systems incorporating Vacuum Insulation Panels and Phase Change Materials. Fire Saf. J. 2016,81, 8–16. [CrossRef] 17. EN 13279-1; Gypsum Binders and Gypsum Plasters—Part 1: Definitions and Requirements. CEN: Brussels, Belgium, 2009. 18. ˇ CSN 73 0802; Fire Protection of Buildings—Non-Industrial Buildings. ÚNMZ: Prague, Czech Republic, 2009. 19. Zhuk, P. Lifecycle analysis of finishing products enhanced with phase changing materials. IOP Conf. Ser. Earth Environ. Sci. 2019 , 323, 012154. [CrossRef] 20. RAL German Institute for Quality Assurance and Certification. Phase Change Materials Quality Assurance RAL-GZ 896; RAL Deutsches Institut für Gütesicherung und Kennzeichnung e.V.: Bonn, Germany, 2018; 47p. 21. Pavlík, Z.; Zmeškal, O.; Pavlíková, M.; ˇ Cerný, R. Effect of Heating and Cooling Mode on Temperature and Enthalpy of Phase Changes in PCM Modified Plaster. Appl. Mech. Mater. 2014,595, 149–154. [CrossRef] 22. Ostrý, M.; Dostálová, D.; Klubal, T.; Pˇrikryl, R.; Charvát, P. Micro-encapsulated phase-change materials for latent-heat storage: Thermal characteristics. Mater. Tehnol. 2015,49, 813–816. [CrossRef] 23. Kusama, Y.; Ishidoya, Y. Thermal effects of a novel phase change material (PCM) plaster under different insulation and heating scenarios. Energy Build. 2017,141, 226–237. [CrossRef] 24. Foˇrt, J.; Trník, A.; Pavlík, Z. Cement-Lime Plaster with PCM Addition—A Perspective Material for Moderation of Interior Climate. Key Eng. Mater. 2016,707, 43–50. [CrossRef] 25. Foˇrt, J.; Trník, A.; Pavlík, Z. Influence of PCM Admixture on Thermal Behavior of Composite Plaster. Adv. Mater. Res. 2014 ,1054, 209–214. [CrossRef] 26. Foˇrt, J.; Trník, A.; Pavlík, Z. Utilization of the PCM latent heat for energy savings in buildings. AIP Conf. Proc. 2017 ,1863, 150002. [CrossRef] 27. Tyagi, V.V.; Kaushik, S.C.; Tyagi, S.K.; Akiyama, T. Development of phase change materials based microencapsulated technology for buildings: A review. Renew. Sustain. Energy Rev. 2011,15, 1373–1391. [CrossRef] 28. Foˇrt, J.; Madˇera, J.; Trník, A.; Pavlíková, M.; Pavlík, Z. Computational modeling of latent-heat-storage in PCM modified interior plaster. AIP Conf. Proc. 2016,1738, 280002. [CrossRef] 29. Klimeš, L.; Charvát, P.; Ostrý, M. An optimization study into thermally activated wall system with latent heat thermal energy storage. IOP Conf. Ser. Earth Environ. Sci. 2019,238, 012016. [CrossRef] 30. Pavlíková, M.; Pavlík, Z.; Trník, A.; Pokorný, J.; ˇ Cerný, R. Characterization of a lime-pozzolan plaster containing phase change material. AIP Conf. Proc. 2015,1648, 090004. [CrossRef] 31. Zhou, G.; Zhang, Y.; Wang, X.; Lin, K.; Xiao, W. An assessment of mixed type PCM-gypsum and shape-stabilized PCM plates in a building for passive solar heating. Sol. Energy 2007,81, 1351–1360. [CrossRef] 32. Theodoridou, M.; Kyriakou, L.; Ioannou, I. PCM-enhanced Lime Plasters for Vernacular and Contemporary Architecture. Energy Procedia 2016,97, 539–545. [CrossRef] Materials 2022,15, 1253 17 of 17 33. Kheradmand, M.; Azenha, M.; Castro-Gomes, J.P.; De Aguiar, J.L.B. Energy benefits of cement-based plaster containing hybrid phase-change material. Proc. Inst. Civ. Eng.—Constr. Mater. 2018,171, 117–125. [CrossRef] 34. Kusama, Y.; Ishidoya, Y. Study on a tankless solar heating system using phase-change material plaster. Build. Environ. 2018 ,127, 256–267. [CrossRef] 35. Carbonaro, C.; Cascone, Y.; Fantucci, S.; Serra, V.; Perino, M.; Dutto, M. Energy Assessment of a Pcm–Embedded Plaster: Embodied Energy versus Operational Energy. Energy Procedia 2015,78, 3210–3215. [CrossRef] 36. Mekaddem, N.; Ali, S.B.; Fois, M.; Hannachi, A. Paraffin/ Expanded Perlite/Plaster as Thermal Energy Storage Composite. Energy Procedia 2019,157, 1118–1129. [CrossRef] 37. Foˇrt, J.; Trník, A.; Pavlíková, M.; Pavlík, Z.; ˇ Cerný, R. Fabrication of Dodecanol/Diatomite Shape-Stabilized PCM and Its Utilization in Interior Plaster. Int. J. Thermophys. 2018,39, 137. [CrossRef] 38. Sari, A.; Bicer, A.; Karaipekli, A.; Al-Sulaiman, F.A. Preparation, characterization and thermal regulation performance of cement based-composite phase change material. Sol. Energy Mater. Sol. Cells 2018,174, 523–529. [CrossRef] 39. Karaipekli, A.; Sari, A.; Biçer, A. Thermal regulating performance of gypsum/(C18–C24) composite phase change material (CPCM) for building energy storage applications. Appl. Therm. Eng. 2016,107, 55–62. [CrossRef] 40. Gnanachelvam, S.; Ariyanayagam, A.; Mahendran, M. Fire resistance of LSF wall systems lined with different wallboards including bio-PCM mat. J. Build. Eng. 2020,32, 101628. [CrossRef] 41. Yoo, D.H.; Jeon, I.K.; Kim, H.G.; Lee, J.S.; Ryou, J.-S. Experimental evaluation of fire resistance performance of cement mortar with PCM/Mg(OH)2-based composite fine aggregate. Constr. Build. Mater. 2021,287, 123018. [CrossRef] 42. Jiang, Y.; Yan, P.; Wang, Y.; Zhou, C.; Lei, J. Form-stable phase change materials with enhanced thermal stability and fire resistance via the incorporation of phosphorus and silicon. Mater. Des. 2018,160, 763–771. [CrossRef] 43. Zhang, Y.; Tang, B.; Wang, L.; Lu, R.; Zhao, D.; Zhang, S. Novel hybrid form-stable polyether phase change materials with good fire resistance. Energy Storage Mater. 2017,6, 46–52. [CrossRef] 44. Pavlík, Z.; Trník, A.; Keppert, M.; Pavlíková, M.; Žumár, J.; ˇ Cerný, R. Experimental Investigation of the Properties of Lime-Based Plaster-Containing PCM for Enhancing the Heat-Storage Capacity of Building Envelopes. Int. J. Thermophys. 2014 ,35, 767–782. [CrossRef] 45. EN 13914-2; Design, Preparation and Application of External Rendering and Internal Plastering—Part 2: Internal Rendering. CEN: Brussels, Belgium, 2016. 46. Toppi, T.; Mazzarella, L. Gypsum based composite materials with micro-encapsulated PCM: Experimental correlations for thermal properties estimation on the basis of the composition. Energy Build. 2013,57, 227–236. [CrossRef] 47. EN 13501-1; Fire Classification of Construction Products and Building Elements—Part 1: Classification Using Test Data from Reaction to Fire Tests. CEN: Brussels, Belgium, 2019. 48. ˇ CSN 72 2301; Plaster Binders. Classification. Common Technical Requirements. Testing Methods. ÚNM: Prague, Czech Republic, 1978. 49. Rigips SAINT-GOBAIN. Rimano UNI. Available online: https://www.rigips.cz/produkty/rimano-uni/ (accessed on 12 December 2021). 50. EN 13279-2; Gypsum Binders and Gypsum Plasters—Part 2: Test Methods. CEN: Brussels, Belgium, 2014. 51. EN ISO 11925-2; Reaction to Fire Tests—Ignitability of Products Subjected to Direct Impingement of Flame—Part 2: Single-Flame Source Test. CEN: Brussels, Belgium, 2020. 52. ˇ CSN 72 1105; Determination of the Coefficient of Thermal Conductivity by the Method of Non-Stationary Flow. FÚNM: Prague, Czech Republic, 1991. 53. Applied Precision Ltd. ISOMET 2114 Thermal Properties Analyzer User’s Guide. Version 1.46, Support and Downolands. Available online: https://www.appliedp.com/download/catalog/isomet_pc_en.pdf (accessed on 3 December 2021). 54. Setaram Instrumentation. SENSYS Evo DSC. Available online: https://intercovamex.com/product/sensys-evo/?lang=en (accessed on 3 December 2021). 55. EN ISO 1716; Reaction to Fire Tests for Products—Determination of the Gross Heat of Combustion (Calorific Value). CEN: Brussels, Belgium, 2018. 56. Lewry, A.J.; Williamson, J. The setting of gypsum plaster: Part II The development of microstructure and strength. J. Mater. Sci. 1994,29, 5524–5528. [CrossRef] 57. Lewry, A.J.; Williamson, J. The setting of gypsum plaster: Part III The effect of additives and impurities. J. Mater. Sci. 1994 ,29, 6085–6090. [CrossRef] 58. Raouf, Z.A.M.; Mahdy, N.; Awad, H. Improving the Properties of Gypsum by Using Additives. J. Eng. 2012,18, 1–18. 59. Aljalawi, N.; Awad, H. A Study of the Effect of Using Additives on Some Properties of Gypsum. In Proceedings of the 1st International Conference on Engineering Sciences Applications ICESA, Karbala, Iraq, 24–25 December 2014. 60. Zhang, B.; Tian, Y.; Jin, X.; Lo, T.Y.; Cui, H. Thermal and Mechanical Properties of Expanded Graphite/Paraffin Gypsum-Based Composite Material Reinforced by Carbon Fiber. Materials 2018,11, 2205. [CrossRef] 61. Stejskalová, K.; Ostrý, M. Influence of phase change materials on thermal stability in attic rooms. Int. Multidiscip. Sci. GeoConf. Surv. Geol. Min. Ecol. Manag. SGEM 2019,19, 183–189. [CrossRef]