Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Experimental Investigation of a New Design of Insulation Gypsum Plaster Blocks

Experimental Investigation of a New Design of Insulation Gypsum Plaster Blocks buildings Article Experimental Investigation of a New Design of Insulation Gypsum Plaster Blocks 1 , 1 2 , 3 Herda Yati Binti Katman * , Wong Jee Khai , Omrane Benjeddou * and Nuha Mashaan Institute of Energy Infrastructure, Universiti Tenaga National, Putrajaya Campus, Jalan IKRAM-UNITEN, Kajang 43000, Selangor, Malaysia Civil Engineering Department, College of Engineering, Prince SattamBin Abdulaziz University, Alkharj 16273, Saudi Arabia Department of Civil Engineering, School of Civil and Mechanical Engineering, Curtin University, Kent Street, Bentley, WA 6102, Australia * Correspondence: herda@uniten.edu.my (H.Y.B.K.); benjeddou.omrane@gmail.com (O.B.) Abstract: Green building materials are an alternative to ordinary materialsoffering multiple environ- mental benefits. This study consists of an experimental investigation of a new design of gypsum plaster blocks. First, a mix design of gypsum plaster and water mixture was prepared. The optimal mix composition was determined according to the mechanical and physical properties, such as the water absorption, the temperature of hydration, the density, and the compressive strength of different gypsum plaster and water mixtures made by varying the water dosage. The second part of this investigation aims to study a new design of green blocks prepared from the optimal water and gypsum plaster mixture. The new blocks are perforated to lighten them and to reduce their thermal conductivity in order to make them moreinsulate. Experimental tests were conducted on the block prototype, such as the measurement of dimensional tolerances, compressive strength, density, flatness, water absorption, residual moisture, surface hardness, and thermal conductivity. Experimental test results show that the new blocks have very low density, and their compressive strength is sufficient Citation: Binti Katman, H.Y.; Khai, for wall construction. In addition, the manufacturing process of the new blocks is very easy and very W.J.; Benjeddou, O.; Mashaan, N. Experimental Investigation of a New fast. Finally, the obtained physical and mechanical properties of the new gypsum plaster blocks give Design of Insulation Gypsum Plaster it the opportunity to be used for interior walls for building constructions. Blocks. Buildings 2022, 12, 1297. https://doi.org/10.3390/ Keywords: experimental investigation; energy; insulation; green; gypsum plaster; mixture; block buildings12091297 Academic Editors: Luca Pelà and Antonio Formisano 1. Introduction Received: 12 May 2022 The traditional fired clay bricks industry is a source of environmental pollution. This is Accepted: 10 August 2022 due to the high gas emissions into the atmosphere generated during the process of firing in Published: 24 August 2022 this industry [1]. In order to resolve this problem, little research has investigated reducing Publisher’s Note: MDPI stays neutral or controlling the gases evolved from the firing process of the clay bricks industry. In this with regard to jurisdictional claims in case, Santos et al. [2] and Toledo et al. [3] studied the correlations between clay properties published maps and institutional affil- and the amount of gas emissions as a function of the temperature of firing. On the other iations. hand, Gonzalez et al. [4] and Cusido et al. [5] show that the control of mineral contents of clay and the temperature during the firing process allows reducing gas emissions, especially fluorine, chlorine, and sulfur gases. Nowadays, researchers investigated new materials for the development of sustainable Copyright: © 2022 by the authors. green blocks. This aims first to decrease the traditional brick industry’s impacts on human Licensee MDPI, Basel, Switzerland. health and on the environment, and second, to reduce the high energy consumption of the This article is an open access article traditional brick industry. distributed under the terms and Gypsum plaster is one of materials providing many solutions to conventional ma- conditions of the Creative Commons terial problems. This is due to its interesting physical and mechanical properties, such Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ as low thermal conductivity, low density, and high firing resistance [6]. Many studies 4.0/). have investigated the improvement of the thermal insulation of gypsum plaster blocks for Buildings 2022, 12, 1297. https://doi.org/10.3390/buildings12091297 https://www.mdpi.com/journal/buildings Buildings 2022, 12, 1297 2 of 17 interior walls [7–12]. Other studies have investigated the incorporation of other natural raw materials and chemical additives in gypsum plaster blocks to improve their physical properties, especially the thermal conductivity and the density [13–17]. In the other case, the results of the works of Zach et al. [18], Korjenic et al. [14], and Hroudová et al. [17] show that the capillary activity of gypsum plaster blocks has a significant effect on the residual moisture of buildings. In addition, Gencel et al. [19], Khalil et al. [20], and Be- nazzouk et al. [21] show that the mechanical and physical properties of gypsum plaster mixture are improved by adding some additives’ waste to the mixtures. As an example, Gencel et al. [19] demonstrate that the sound-proofing property and thermal property of gypsum plaster mixture were improved by adding pore-forming agents. Finally, this study aims to explore the advantages of gypsum plaster mixture for developing a new design of gypsum plaster blocks perforated using circular alveolar. he holes perforated on blocks aim to lighten them and to reduce their thermal conductivity in order to make them more insulate. Notice that if the mechanical and physical properties of the new blocks verify the requirements of the international standards, they will be a good alternative for the con- struction of buildings interior walls with high thermal insulation. The first part of this study consists of studying both the physical and chemical proper- ties of the used gypsum plaster. The second part aims to elaborate an optimal mix design of gypsum plaster and water mortar. The second parts consists of evaluating both the physical and mechanical properties of the optimal mixture. The third part aims to validate the possibility of use of perforated gypsum plaster as an ecological green block by experimental tests on the newly designed block prototypes. 2. Experimental Program The objective of this work is the development of new perforated blocks using gypsum plaster and water mixture. The experimental study flow chart representing all conducted experiment tests is shown in Figure 1. The main parts of this experimental study are the following: - Evaluate the chemical, physical, and mineral properties of the gypsum plaster used in this study, such as: Chemical composition using an X-ray fluorescence spectrometry (XRF). Microstructure analysis by scanning electron microscope. Particle size analysis. Densities. Blaine specific surface (BSS). - Mix design of gypsum plaster and water mixture in order to determine the optimal mixture composition. - Study of the mechanical and the physical properties of gypsum and water mixture, such as: Density. Water absorption. Temperature of hydration. Compressive strength. - Preparation of the block prototypes. - Study of the mechanical and the physical properties of gypsum plaster block prototype: Dimensional tolerances. Density. Compressive strength. Flatness. Residual moisture. Water absorption. Surface hardness. Buildings 2022, 12, x FOR PEER REVIEW 3 of 18 Buildings 2022, 12, 1297 3 of 17 • Residual moisture. • Water absorption. • Surface hardness. • Therma Thermal l conducti conductivity vity. . Figure 1. Experimental study flow chart. Figure 1. Experimental study flow chart. 3. Materials and Methods 3. Materials and Methods 3.1. Gypsum Plaster 3.1. Gypsum Plaster 3.1.1. Chemical Analysis 3.1.1. Chemical Analysis Gypsum plaster used in this work is a local product. The chemical analysis was Gypsum plaster used in this work is a local product. The chemical analysis was performed by an X-ray fluorescence spectrometry (XRF). This test consists of evaluating the performed by an X-ray fluorescence spectrometry (XRF). This test consists of evaluating content in percent of Al O , CaO, F O , K O, MgO, Na O, SiO and SO . The chemical 2 3 e2 3 2 2 2, 3 the content in percent of Al2O3, CaO, Fe2O3, K2O, MgO, Na2O, SiO2, and SO3. The chemical analysis result of gypsum plaster is presented in Table 1. Result shows that the tested analysis result of gypsum plaster is presented in Table 1. Result shows that the tested gypsum plaster is too rich in calcium oxide (CaO  35%) and in sulfur dioxide (SO  47%). 3 Buildings 2022, 12, x FOR PEER REVIEW 4 of 18 Buildings 2022, 12, 1297 4 of 17 gypsum plaster is too rich in calcium oxide (CaO ≈ 35%) and in sulfur dioxide (SO3 ≈ 47%). Table 1. Gypsum plaster chemical composition. Table 1. Gypsum plaster chemical composition. Component Al O CaO Fe O K2O MgO Na O SO SiO 2 3 2 3 2 3 2 Component Al2O3 CaO Fe2O3 K2O MgO Na2O SO3 SiO2 Percentage 0.10 34.85 0.08 0.03 0.53 0.09 46.63 0.70 Percentage 0.10 34.85 0.08 0.03 0.53 0.09 46.63 0.70 3.1.2. Microstructure Analysis by Scanning Electron Microscope 3.1.2. Microstructure Analysis by Scanning Electron Microscope The morphological forms of the used gypsum plaster were studied using a scanning The morphological forms of the used gypsum plaster were studied using a scanning Electron Microscope (SEM). Results of SEM image, presented in Figure 2, show that al- Electron Microscope (SEM). Results of SEM image, presented in Figure 2, show that al- most all plaster grains have a spherical shape, which means that this gypsum plaster is most all plaster grains have a spherical shape, which means that this gypsum plaster is highly semihydrated. highly semihydrated. Figure 2. SEM image of marble paste (×10,000). Figure 2. SEM image of marble paste (10,000). 3.1.3. Particle Size Analysis 3.1.3. Particle Size Analysis The distribution of gypsum plaster grain size was carried out using the sedimentation The distribution of gypsum plaster grain size was carried out using the sedimenta- method according to NF P 94-057 [22] standard requirements. tion method according to NF P 94-057 [22] standard requirements. Figure 3 shows the curve the distribution of the particle size of gypsum plaster. Figure 3 shows the curve the distribution of the particle size of gypsum plaster. According to this curve, the fineness modulus is about 0.95, which means that the tested According to this curve, the fineness modulus is about 0.95, which means that the tested plaster is very fine. plaster is very fine. Two other important factors, characterizing grains size distribution, are determined: the curvature coefficient (C ) and the uniformity coefficient (C ). C and C are expressed c u c u as follow [23]: D D 30 30 C = (1) D D 10 60 C = (2) where D , D , and D are the grain size at 10%, 30%, and 60% passing, respectively. 10 30 60 Test results indicate that C and C of the used gypsum plaster are, respectively, 5.6 u c and 1.6. Indeed, due to C > 2 and 1 < C < 3, it can be concluded that the gypsum plaster u c is effectively graded and graduated. Buildings 2022, 12, 1297 5 of 17 Buildings 2022, 12, x FOR PEER REVIEW 5 of 18 0.001 0.01 0.1 1 0,001 0,01 0,1 1 Diameter (mm) Figure 3. Particle size distribution of gypsum plaster. Figure 3. Particle size distribution of gypsum plaster. Two other important factors, characterizing grains size distribution, are determined: 3.1.4. Physical Properties the curvature coefficient (Cc) and the uniformity coefficient (Cu). Cc and Cu are expressed Table 2 presents the physical properties of gypsum plaster. Tests results demonstrate as follow [23]: that gypsum plaster has a bulk density and an absolute density equal to 0.60 g/cm and 2.65 g/cm , respectively. Results also show that D.D the Blaine specific surface (BSS) of gypsum 30 30 C = 2 (1) plaster, determined using the NF EN 196-6 [24] requirements, is about 5705 cm /g. This D.D 10 60 result confirms that gypsum plaster used in this study is very fine. (2) C = Table 2. Physical properties of gypsum plaster. where D10, D30, and D Absolute 60 are th Density e grain size at 10%, 30%, and 60% passing, resp Blaine Specific ectively. Surface Parameters Particle Size (mm) Bulk Density (g/cm ) 3 2 (g/cm ) (BSS) (cm /g) Test results indicate that Cu and Cc of the used gypsum plaster are, respectively, 5.6 and 1.6. Indeed, due to Cu > 2 and 1 < Cc < 3, it can be concluded that the gypsum plaster is Standard NF P 94-056 [22] NF EN 1097-7 [25] NF EN 196-6 [24] effectively graded and graduated. Test result 0/0.5 2.65 0.60 5705 3.1.4. Physical Properties 3.2. Tests Setup on Gypsum Plaster and Water Mixture Table 2 presents the physical properties of gypsum plaster. Tests results demon- 3.2.1. Mix Design of the Mixture strate that gypsum plaster has a bulk density and an absolute density equal to 0.60 g/cm and 2.65 g/cm , respectively. Results also show that the Blaine specific surface (BSS) of The objective of this part is to evaluate the mix design of the gypsum plaster and gypsum plaster, determined using the NF EN 196-6 [24] requirements, is about 5705 water mixture. The appropriate water volume is that given a workability that makes the cm /g. This result confirms that gypsum plaster used in this study is very fine. mixture molding without any vibration process easy. To perform this, different mixtures are prepared by varying the water/gypsum plaster ratio, and thereafter their flow times Table 2. Physical properties of gypsum plaster. were measured by using an LCL mortar maniabilimeter (Figure 4). The flow time Partic measur le Size ements Absolute results Densi are tpr y esented Bulk Densi- in Table Blaine Sp 3 and in ecif Figur ic Sur e 4 -. The Parameters 3 3 2 presented results show that the flow time decreases when increasing the water amount. In (mm) (g/cm ) ty(g/cm ) face (BSS) (cm /g) addition, results of Figure 5 show that until a water/gypsum plaster ratio of 0.60, the flow Standard NF P 94-056 [22] NF EN 1097-7 [25] NF EN 196-6 [24] times of the mixtures remain constant, and thereafter the workability of these mixtures Test result 0/0.5 2.65 0.60 5705 is the same. As a conclusion, the water amount is chosen as equal to 60% of the gypsum plaster amount. 3.2. Tests Setup on Gypsum Plaster and Water Mixture 3.2.1. Mix Design of the Mixture Cumulative (%) Buildings 2022, 12, x FOR PEER REVIEW 6 of 18 Buildings 2022, 12, x FOR PEER REVIEW 6 of 18 The objective of this part is to evaluate the mix design of the gypsum plaster and water mixture. The appropriate water volume is that given a workability that makes the mixture molding without any vibration process easy. To perform this, different mixtures The objective of this part is to evaluate the mix design of the gypsum plaster and are prepared by varying the water/gypsum plaster ratio, and thereafter their flow times water mixture. The appropriate water volume is that given a workability that makes the were measured by using an LCL mortar maniabilimeter (Figure 4). mixture molding without any vibration process easy. To perform this, different mixtures Buildings 2022, 12, 1297 6 of 17 are prepared by varying the water/gypsum plaster ratio, and thereafter their flow times were measured by using an LCL mortar maniabilimeter (Figure 4). Figure 4. Measurement of flow time using LCL mortar maniabilimeter. The flow time measurements results are presented in Table 3 and in Figure 4. The presented results show that the flow time decreases when increasing the water amount. In addition, results of Figure 5 show that until a water/gypsum plaster ratio of 0.60, the Figure 4. Measurement of flow time using LCL mortar maniabilimeter. Figure 4. Measurement of flow time using LCL mortar maniabilimeter. flow times of the mixtures remain constant, and thereafter the workability of these mix- tures is the same. As a conclusion, the water amount is chosen as equal to 60% of the T gyp able sum The flow 3. p Results laster am tim of flow oe u measureme nttime . measur nements ts results test.are presented in Table 3 and in Figure 4. The presented results show that the flow time decreases when increasing the water amount. Table 3. Results of flow time measurements test. Water/Gypsum plaster 0.54 0.58 0.59 0.60 0.61 0.62 0.63 0.64 In addition, results of Figure 5 show that until a water/gypsum plaster ratio of 0.60, the Flow time (s) flow times of the mixtures remain const 5.23 4.53 3.41 2.38 ant, and ther 1.99 eafter the wo 1.75 rkability 1.55 of these mix- 1.49 Water/Gypsum plaster 0.54 0.58 0.59 0.60 0.61 0.62 0.63 0.64 tures is the same. As a conclusion, the water amount is chosen as equal to 60% of the Flow time (s) 5.23 4.53 3.41 2.38 1.99 1.75 1.55 1.49 gypsum plaster amount. Table 3. Results of flow time measurements test. Water/Gypsum plaster 0.54 0.58 0.59 0.60 0.61 0.62 0.63 0.64 Flow time (s) 5.23 4.53 3.41 2.38 1.99 1.75 1.55 1.49 1 4 0.52 0.54 0.56 0.58 0.60 0.62 0.64 0.66 0,52 0,54 0,56 0,58 0,6 0,62 0,64 0,66 Water/Gypsum plaster Figure 5. Flow time as function of water/gypsum plaster ratio. Figure 5. Flow time as function of water/gypsum plaster ratio. 3.2.2. Test Specimens Preparation 3.2.2. Test Specimens Preparation In this experimental study, cubic and cylindrical specimens are manufactured using a gypsum plaster and 60% water mixture. The dimensions and the number of each specimen 0.52 0.54 0.56 0.58 0.60 0.62 0.64 0.66 0,52 0,54 0,56 0,58 0,6 0,62 0,64 0,66 shape per test are shown in Table 4. Water/Gypsum plaster Table 4. Specimens shape and dimensions. Figure 5. Flow time as function of water/gypsum plaster ratio. Test Specimen Shape Specimen Dimensions Number of SpecimensbyTest 3.2.2. Test Specimens Preparation Density Cubic 100  100  100 mm 3 Absorption degree Cubic 100  100  100 mm 3 Hydration temperature Cubic 100  100  100 mm 3 Compressive strength Cylindrical 50  100 mm 12 The mixing process of gypsum plaster and water mixture are the following: Flow time [s] Flow time [s] Buildings 2022, 12, x FOR PEER REVIEW 7 of 18 In this experimental study, cubic and cylindrical specimens are manufactured using a gypsum plaster and 60% water mixture. The dimensions and the number of each specimen shape per test are shown in Table 4. Table 4. Specimens shape and dimensions. Test Specimen Shape Specimen Dimensions Number of SpecimensbyTest Density Cubic 100×100 × 100 mm 3 Absorption degree Cubic 100 × 100 × 100 mm 3 Hydration temperature Cubic 100 × 100 × 100 mm 3 Buildings 2022 Compr , 12, 1297 essive strength Cylindrical 50 × 100 mm 12 7 of 17 The mixing process of gypsum plaster and water mixture are the following: n Add the gypsum plaster amount to 60% water (Figure 6a).  Add the gypsum plaster amount to 60% water (Figure 6a). n Mix in wet condition first for 30 s with slow speed and then for 1 min with high speed  Mix in wet condition first for 30 s with slow speed and then for 1 min with high (Figure 6b). speed (Figure 6b). n Prepare the molds (Figure 6c,d).  Prepare the molds (Figure 6c,d). n Pour the mixture on the molds (Figure 6e).  Pour the mixture on the molds (Figure 6e). n Dry the specimens for 10 min before demolding (Figure 6f,g).  Dry the specimens for 10 min before demolding (Figure 6f,g). n Demold the specimens (Figure 6h).  Demold the specimens (Figure 6h). n Finally, keep specimens under a temperature degree of 23 C and a relative humidity  Finally, keep specimens under a temperature degree of 23 °C and a relative humid- between 55 and 65% to the testing date. ity between 55 and 65% to the testing date. Figure 6. Steps of specimens’ preparation process :(a) Add the gypsum plaster to water, (b) Mix in Figure 6. Steps of specimens’ preparation process: (a) Add the gypsum plaster to water, wet condition, (c,d) Molds preparation, (e) Molds casting, (f,g) Specimens drying, (h) Specimens (b) Mix in wet condition, (c,d) Molds preparation, (e) Molds casting, (f,g) Specimens drying, demolding (h) Specimens demolding. 3.2.3. Density 3.2.3. Density Buildings 2022, 12, x FOR PEER REVIEW 8 of 18 Density measurements consist, as presented in Figure 7, of weighting a cubic specimen Density measurements consist, as presented in Figure 7, of weighting a cubic as a function of time until its mass is stabilized. specimen as a function of time until its mass is stabilized. Figure 7. Density measurement process. Figure 7. Density measurement process. 3.2.4. Water Absorption Degree This test consists of measuring the mass of water absorbed by a cubic specimen of gypsum plaster and water mixture as a function of time. Measurement process steps, presented in Figure 8, consist of weighting the sample both in its dry state and in its wet state. Figure 8. Measurement of specimen absorption degree. 3.2.5. Temperature of Hydration Measurement of the hydration temperature of gypsum plaster and water mixture steps are as follows:  Prepare an insulating cubic mold (Figure 9a).  Pour the mixture on the molds (Figure 9b).  Place a thermometer in a copper tube containing oil in the specimen center (Figure 9c).  Measure hydration temperature with time.  Measure the ambient temperature using another thermometer. Buildings 2022, 12, x FOR PEER REVIEW 8 of 18 Buildings 2022, 12, x FOR PEER REVIEW 8 of 18 Buildings 2022, 12, 1297 8 of 17 Figure 7. Density measurement process. Figure 7. Density measurement process. 3.2.4. Water Absorption Degree 3.2.4. Water Absorption Degree 3.2.4. Water Absorption Degree This This test te st cons cons ist ist s sof of me meas asu ur ring ing t th he m e m aa sss of s of w w ater ater ab ab sorbed by sorbed by a c ua c bicu spec bic spec imenime of n of This test consists of measuring the mass of water absorbed by a cubic specimen of gypsum plaster and water mixture as a function of time. Measurement process steps, gypsum plaster and water mixture as a function of time. Measurement process steps, gypsum plaster and water mixture as a function of time. Measurement process steps, presented in Figure 8, consist of weighting the sample both in its dry state and in its wet presented in Figure 8, consist of weighting the sample both in its dry state and in its wet presented in Figure 8, consist of weighting the sample both in its dry state and in its state. state. wet state. Figure 8. Measurement of specimen absorption degree. Figure 8. Measurement of specimen absorption degree. Figure 8. Measurement of specimen absorption degree. 3.2.5. Temperature of Hydration Measurement of the hydration temperature of gypsum plaster and water mixture 3.2.5. Temperature of Hydration 3.2.5. Temperature of Hydration steps are as follows: Measurement of the hydration temperature of gypsum plaster and water mixture Measurement of the hydration temperature of gypsum plaster and water mixture  Prepare an insulating cubic mold (Figure 9a). steps are as follows: steps are as follows:  Pour the mixture on the molds (Figure 9b). n Prepare an insulating cubic mold (Figure 9a).  Place a thermometer in a copper tube containing oil in the specimen center (Figure  Prepare an insulating cubic mold (Figure 9a). n Pour the mixture on the molds (Figure 9b). 9c).  Pour the mixture on the molds (Figure 9b). n Place a thermometer in a copper tube containing oil in the specimen center (Figure 9c).  Measure hydration temperature with time.  n Place a t Measur he erm hydration ometer in a c temperatur oppe er t with ubtime. e containing oil in the specimen center (Figure  Measure the ambient temperature using another thermometer. n Measure the ambient temperature using another thermometer. 9c).  Measure hydration temperature with time.  Measure the ambient temperature using another thermometer. Figure 9. Measurement of hydration temperature: (a) Preparation of insulating cubic mold, (b) Molds casting, (c) Thermometer placing. 3.2.6. Compressive Strength Compressive strength tests are carried out on cylindrical specimens of gypsum plaster mixture at the ages of 1, 3, 5, 7, 14, 21, and 28 days. Compressive tests were carried out using a UTM machine according to the requirements of EN 12390-4 [26] standard. 4. Properties of Gypsum Plaster and Water Mixture 4.1. Density The density measurement results of gypsum plaster and water mixture are presented in Table 5. Results show that the initial density, measured just after removing the specimen, 3, is about 1.711 g/cm and the stabilized density, measured after specimen mass stabilization, is about 1.278 g/cm . Indeed, the total water loss is about 25.30% of the initial weight. Buildings 2022, 12, x FOR PEER REVIEW 9 of 18 Figure 9. Measurement of hydration temperature : (a) Preparation of insulating cubic mold, (b) Molds casting, (c) Thermometer placing 3.2.6. Compressive Strength Compressive strength tests are carried out on cylindrical specimens of gypsum plaster mixture at the ages of 1, 3, 5, 7, 14, 21, and 28 days. Compressive tests were carried out using a UTM machine according to the requirements of EN 12390-4 [26] standard. 4. Properties of Gypsum Plaster and Water Mixture 4.1.Density The density measurement results of gypsum plaster and water mixture are pre- sented in Table 5. Results show that the initial density, measured just after removing the Buildings 2022, 12, 1297 9 of 17 3, specimen, is about 1.711 g/cm and the stabilized density, measured after specimen mass stabilization, is about 1.278 g/cm . Indeed, the total water loss is about 25.30% of the ini- tial weight. Figure 10 presents the density of mixture and time relationship. Two conclusions are Table 5. Physical properties of gypsum plaster specimen. deduced from this result: first, the density of specimen decreases with time, and second, the weight of the specimen was stabilized after 16 days, which is the end of the hardening Final Density Degree of Absorption Initial Density (g/cm ) Water Loss (%) (g/cm ) (%) step. Finally, a final density of 1.278 g/cm classifies the gypsum plaster blocks as 1.711 1.278 25.30 24.3 high-density building materials [27]. Table 5. Physical properties of gypsum plaster specimen. Figure 10 presents the density of mixture and time relationship. Two conclusions are deduced from this result: first, the density of specimen decreases with time, and second, the 3 3 Initial Density (g/cm ) Final Density (g/cm ) Water Loss (%) Degree of Absorption (%) weight of the specimen was stabilized after 16 days, which is the end of the hardening step. 1.711 1.278 25.30 24.3 0 2 4 6 8 10 1214 161820 Time (Days) Figure 10. Gypsum plaster density as function of time. Figure 10. Gypsum plaster density as function of time. 4.2. Degree of Absorption Finally, a final density of 1.278 g/cm classifies the gypsum plaster blocks as high- The results presented in Table 5 show that the maximum water absorption of gyp- density building materials [27]. sum plaster specimen is about 24.3%. The curve presented in Figure 11 shows the ab- sorption degree and time relationship. It can be concluded that the absorption degree of 4.2. Degree of Absorption the specimen increases with time, and the maximum absorption degree was reached after The results presented in Table 5 show that the maximum water absorption of gypsum 25 h. Results also show that 50% of the maximum degree of absorption was reached plaster specimen is about 24.3%. The curve presented in Figure 11 shows the absorption during only the three first hours. degree and time relationship. It can be concluded that the absorption degree of the specimen increases with time, and the maximum absorption degree was reached after 25 h. Results Buildings 2022, 12, x FOR PEER REVIEW 10 of 18 also show that 50% of the maximum degree of absorption was reached during only the three first hours. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (h) Figure 11. Specimen absorption degree as a function of time. Figure 11. Specimen absorption degree as a function of time. 4.3. Temperature of Hydration The curve of temperature of gypsum plaster and water specimen as a function of time is presented in Figure 12. The first remark observed from this curve is that the maximum temperature of the mixture is about 47°C, reached during the first 25 min. The second remark is that the setting of mixture due to the hydration reaction is very quick. Indeed, setting begins only after 10 min and finishes after nearly 25 min. As a conse- quence, a quick block removing is possible. 0 20406080 100 120 140 160 180 200 Time (min) Figure 12. Temperature of gypsum plaster and water specimen versus time. 4.4. Compressive Strength The compressive strength results at the ages of 1, 3, 5, 7, 14, 21, and 28 days are presented in Table 6. Results show that the maximum strength of gypsum plaster and water specimen, of about 11.2 MPa, was reached after 21 days. In addition, 50% of its maximum compression strength was reached only after one day. Figure 13 shows the curve of the compressive strength as function of strain after weight stabilization. According to this curve, it can be concluded that the gypsum plaster specimen has a nonlinear elastic behavior. Temperature (°C) Degree of absorption (%) Density (kg/m ) Buildings 2022, 12, x FOR PEER REVIEW 10 of 18 Buildings 2022, 12, 1297 10 of 17 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (h) Figure 11. Specimen absorption degree as a function of time. 4.3. Temperature of Hydration The curve of temperature of gypsum plaster and water specimen as a function of time 4.3. Temperature of Hydration is presented in Figure 12. The first remark observed from this curve is that the maximum The curve of temperature of gypsum plaster and water specimen as a function of temperatur time is presented i e of the n Figure mixtur 12. The e is about first rema 47rk observed C, reached from during this curve theisfirst that the 25 min. The second maximum temperature of the mixture is about 47°C, reached during the first 25 min. The remark is that the setting of mixture due to the hydration reaction is very quick. Indeed, second remark is that the setting of mixture due to the hydration reaction is very quick. setting begins only after 10 min and finishes after nearly 25 min. As a consequence, a quick Indeed, setting begins only after 10 min and finishes after nearly 25 min. As a conse- block removing is possible. quence, a quick block removing is possible. 0 20406080 100 120 140 160 180 200 Time (min) Figure 12. Temperature of gypsum plaster and water specimen versus time. Figure 12. Temperature of gypsum plaster and water specimen versus time. 4.4. Compressive Strength 4.4. Compressive Strength The compressive strength results at the ages of 1, 3, 5, 7, 14, 21, and 28 days are The compressive strength results at the ages of 1, 3, 5, 7, 14, 21, and 28 days are presented in Table 6. Results show that the maximum strength of gypsum plaster and water specimen, of about 11.2 MPa, was reached after 21 days. In addition, 50% of its presented in Table 6. Results show that the maximum strength of gypsum plaster and water maximum compression strength was reached only after one day. specimen, of about 11.2 MPa, was reached after 21 days. In addition, 50% of its maximum Figure 13 shows the curve of the compressive strength as function of strain after compression strength was reached only after one day. weight stabilization. According to this curve, it can be concluded that the gypsum plaster specimen has a nonlinear elastic behavior. Table 6. Compressive strength tests results. Buildings 2022, 12, x FOR PEER REVIEW 11 of 18 Age [day] 1 3 5 7 14 21 28 Compressive strength [MPa] 6.7 6.7 6.7 6.5 8.5 11.1 11.2 Table 6. Compressive strength tests results. Figure 13 shows the curve of the compressive strength as function of strain after Age [day] 1 3 5 7 14 21 28 weight stabilization. According to this curve, it can be concluded that the gypsum plaster Compressive strength [MPa] 6.7 6.7 6.7 6.5 8.5 11.1 11.2 specimen has a nonlinear elastic behavior. 0 0.1 0.2 0.3 0.4 0 0,1 0,2 0,3 0,4 Strain (%) Figure 13. Compressive strength–strain curve of gypsum plaster mixture after weight stabilization. Figure 13. Compressive strength–strain curve of gypsum plaster mixture after weight stabilization. 5. Design of New Gypsum Plaster Blocks 5.1. New Blocks Description A new design of blocks made using a water and gypsum plaster mixture was de- veloped. As it is known, the manufacturing process of gypsum plaster blocks is low en- ergy consumption compared with that of ordinary clay fired bricks [5]. In addition, fired bricks are an important source of atmospheric pollution [4]. According to the new design presented in Figure 14, the new blocks are 600 mm in length, 550 mm in height, and 100 mm in thickness. In addition, the new blocks are equipped with a circular alveolar system of 60 mm in diameter. The circular alveolar gives to the gypsum plaster blocks both a high thermal insula- tion and phonic insulation and a high compressive strength. Moreover, gypsum plaster makes the new blocks good hygrometric regulators, which means that they regulate in- ternal humidity by rejecting it outside the room or by absorbing it. Moreover, as known, gypsum plaster blocks have high fire resistance [28]. Finally, the new design of gypsum plaster blocks makes them an important alterna- tive for the construction of interior walls of buildings. Temperature (°C) Degree of absorption (%) Compressive strenght (MPa) Buildings 2022, 12, 1297 11 of 17 5. Design of New Gypsum Plaster Blocks 5.1. New Blocks Description A new design of blocks made using a water and gypsum plaster mixture was devel- oped. As it is known, the manufacturing process of gypsum plaster blocks is low energy consumption compared with that of ordinary clay fired bricks [5]. In addition, fired bricks are an important source of atmospheric pollution [4]. According to the new design presented in Figure 14, the new blocks are 600 mm Buildings 2022, 12, x FOR PEER REVIEW 12 of 18 in length, 550 mm in height, and 100 mm in thickness. In addition, the new blocks are equipped with a circular alveolar system of 60 mm in diameter. Figure 14. Perforated gypsum plaster blocks design. Figure 14. Perforated gypsum plaster blocks design. 5.2. Manufacturing of Gypsum Plaster Block Prototypes The circular alveolar gives to the gypsum plaster blocks both a high thermal insulation and phonic As shown i insulation n Figure 14 and , athe high block compr prototypes essive str ha ength. ve 100 Mor mm × eover 55,0 mm gypsum × 60plaster 0 mm di makes - mensions. the new blocks good hygrometric regulators, which means that they regulate internal The different steps for preparing the block prototypes are the following [29]: humidity by rejecting it outside the room or by absorbing it. Moreover, as known, gypsum plaster blocks have high fire resistance [28].  Prepare the steel mold (Figure 15a). Finally, the new design of gypsum plaster blocks makes them an important alternative  Place the mixture on the mold (Figure 15b). for the construction of interior walls of buildings.  Remove the blocks from the molds after 24 h (Figure 15c).  Dry the blocks on air (Figure 15d). 5.2. Manufacturing of Gypsum Plaster Block Prototypes Finally, the following experimental tests were carried out on the hardened blocks: As shown in Figure 14, the block prototypes have 100 mm  550 mm  600 mm ­ Dimensional tolerances. dimensions. ­ Density. The different steps for preparing the block prototypes are the following [29]: ­ Surface hardness. n Prepare the steel mold (Figure 15a). ­ Residual moisture. n Place the mixture on the mold (Figure 15b). ­ Thermal conductivity. n Remove the blocks from the molds after 24 h (Figure 15c). ­ Compressive strength. ­n Flatne Dry the ss. blocks on air (Figure 15d). Buildings 2022, 12, x FOR PEER REVIEW 13 of 18 Buildings 2022, 12, 1297 12 of 17 Figure 15. The block prototype manufacturing process : (a) Preparation of the steel mold, (b) Mold Figure 15. The block prototype manufacturing process: (a) Preparation of the steel mold, (b) Mold casting, (c) Blocks removing, (d) On air block drying casting, (c) Blocks removing, (d) On air block drying. 5.3. Properties of Gypsum Plaster Blocks Finally, the following experimental tests were carried out on the hardened blocks: 5. - 3.1. D Dimensional imensional Tol tolerances. erances - Density. After hardening, blocks will be expanded due to the hydration of gypsum plaster - Surface hardness. with water and, as consequence, block dimensions increase. he specifications of the - Residual moisture. standard NF EN 12859 [29] show that the maximum accepted tolerances in dimension - Thermal conductivity. change are ±5 mm for length, ±0.5 mm for thickness, and ±2 mm for height. - Compressive strength. The results of Table 7 show that after removing gypsum plaster blocks, their di- - Flatness. mensions increased to 100.3 mm, 550.7 mm, and 600.2 mm for thickness, height, and length, respectively. As a conclusion, the increases in block dimensions are lower than 5.3. Properties of Gypsum Plaster Blocks the maximum recommended tolerances. 5.3.1. Dimensional Tolerances After hardening, blocks will be expanded due to the hydration of gypsum plaster with Table 7. Mechanical and physical properties of gypsum plaster blocks. water and, as consequence, block dimensions increase. he specifications of the standard Property Result NF EN 12859 [29] show that the maximum accepted tolerances in dimension change are Length 600.2 5 mm for length, 0.5 mm for thickness, and 2 mm for height. Dimensional tolerances (mm) Height 550.7 The results of Table 7 show that after removing gypsum plaster blocks, their dimen- sions increased to 100.3 mm, 550.7 mm, and 600.2 mm for thickness, height, and length, Thickness 100.3 respectively. As a conclusion, the increases in block dimensions are lower than the maxi- Drying time (h) 48 mum recommended tolerances. Flatness (mm) 0.5 Density (Kg/m ) 856 Compressive strength (MPa) 5.6 Residual moisture (%) 5 Water absorption (%) 24.3 Surface hardness (shore C) 35 Thermal conductivity (W/mK) 0.45 Buildings 2022, 12, 1297 13 of 17 Table 7. Mechanical and physical properties of gypsum plaster blocks. Property Result Length 600.2 Dimensional tolerances (mm) Height 550.7 Thickness 100.3 Drying time (h) 48 Flatness (mm) 0.5 Density (Kg/m ) 856 Compressive strength (MPa) 5.6 Residual moisture (%) 5 Water absorption (%) 24.3 Buildings 2022, 12, x FOR PEER REVIEW 14 of 18 Surface hardness (shore C) 35 Thermal conductivity (W/mK) 0.45 5.3.2. Flatness 5.3.2. Flatness The specifications of the standard NF EN 12859 [29] show that the maximum devia- The specifications of the standard NF EN 12859 [29] show that the maximum deviation tion of metal ruler placed along the diagonals of the block and the shims must not exceed of metal ruler placed along the diagonals of the block and the shims must not exceed 1 mm. 1 mm. A flatness test made on the block prototypes (Figure 16) showed that its flatness A flatness test made on the block prototypes (Figure 16) showed that its flatness index is index is about 0.5 mm (Table 7). This flatness index is lower than the maximum recom- about 0.5 mm (Table 7). This flatness index is lower than the maximum recommended mended value of 1 mm. value of 1 mm. Figure 16. Flatness of the new gypsum plaster blocks. Figure 16. Flatness of the new gypsum plaster blocks. 5.3.3. Density 5.3.3. Density The results of Table 7 show that the density of the gypsum plaster block is about The results of Table 7 show that the density of the gypsum plaster block is about 856 856 kg/m . As a consequence, gypsum plaster blocks can be considerate as average kg/m . As a consequence, gypsum plaster blocks can be considerate as average density density blocks. blocks. 5.3.4. Compressive Strength 5.3.4. Compressive Strength The results of Table 7 show that the average compressive strength of gypsum plaster The results of Table 7 show that the average compressive strength of gypsum plaster blocks is about 5.6 MPa. This compressive strength value makes possible the use of these blocks is about 5.6 MPa. This compressive strength value makes possible the use of these blocks as building materials for interior walls [27]. blocks as building materials for interior walls [27]. 5.3.5. Residual Moisture 5.3.5. Residual Moisture The residual moisture content of the blocks was determined by weighting the block The residual moisture content of the blocks was determined by weighting the block after it was dried until the stabilization of weight at a temperature of 20  5 C in a after it was dried until the stabilization of weight at a temperature of 20±5 °C in a venti- ventilated room under relative humidity of 65  5% [28]. Results demonstrate that the lated room under relative humidity of 65 ± 5% [28]. Results demonstrate that the average average moisture content of the gypsum plaster block prototype is about 5%. This obtained moisture content of the gypsum plaster block prototype is about 5%. This obtained result result is lower than the maximum recommended value of 6% [28]. is lower than the maximum recommended value of 6% [28]. 5.3.6. Water Absorption The measurement of the degree of water absorption of gypsum plaster blocks was performed in accordance with NF EN 772-21 requirements [30]. The results of Table 7 show the water absorption degree of gypsum plaster blocks is about 24.4%. 5.3.7. Surface Hardness The hardness of blocks surface was measured, using a durometer, on dried blocks. Experimental results show that the hardness of the gypsum plaster blocks surface is about 35 (Table 7). Consequently, the class of the prepared gypsum plaster blocks is as low-density bricks. 5.3.8. Thermal Conductivity The thermal conductivity of gypsum plaster bricks was carried out with the speci- fications of NF EN ISO 8990 standard [31] by using the “boxes method”. The process of this method is presented in Figure 17. Results of Table 7 show that gypsum plaster blocks Buildings 2022, 12, 1297 14 of 17 5.3.6. Water Absorption The measurement of the degree of water absorption of gypsum plaster blocks was performed in accordance with NF EN 772-21 requirements [30]. The results of Table 7 show the water absorption degree of gypsum plaster blocks is about 24.4%. 5.3.7. Surface Hardness The hardness of blocks surface was measured, using a durometer, on dried blocks. Experimental results show that the hardness of the gypsum plaster blocks surface is about 35 (Table 7). Consequently, the class of the prepared gypsum plaster blocks is as low-density bricks. 5.3.8. Thermal Conductivity Buildings 2022, 12, x FOR PEER REVIEW 15 of 18 The thermal conductivity of gypsum plaster bricks was carried out with the spec- ifications of NF EN ISO 8990 standard [31] by using the “boxes method”. The process of this method is presented in Figure 17. Results of Table 7 show that gypsum plas- have an average thermal conductivity of about 0.45 W/mK. As a main conclusion, the ter blocks have an average thermal conductivity of about 0.45 W/mK. As a main con- developed gypsum plaster blocks have a low thermal conductivity value, 0.35 W/mK ≤ λ clusion, the developed gypsum plaster blocks have a low thermal conductivity value, ≤ 0.87 W/mK [31], for use as an insulation building material for the construction of inte- 0.35 W/mK    0.87 W/mK [31], for use as an insulation building material for the con- rior walls. struction of interior walls. Figure 17. Thermal conductivity measurement using boxes method test [27]. Figure 17. Thermal conductivity measurement using boxes method test [27]. 5.4. Discussion 5.4. Discussion Experimental tests results on gypsum plaster block prototypes show that these blocks Experimental tests results on gypsum plaster block prototypes show that these can be an alternative for insulation building materials for interior walls construction. This blocks can be an alternative for insulation building materials for interior walls construc- result makes the possibility to manufacture this new block due to these reasons: tion. This result makes the possibility to manufacture this new block due to these reasons: - They have a tolerated dimensions after drying. ­ They have a tolerated dimensions after drying. - They have a flat surface. ­ They have a flat surface. - They are considered lightweight blocks because of their very low density, about ­ They are considered lightweight blocks because of their very low density, about 865 865 kg/m . kg/m . - They have a recommended compressive strength for wall construction. ­ They have a recommended compressive strength for wall construction. - They can be used only after one day because of their very quick setting. ­ They can be used only after one day because of their very quick setting. Finally, a prototype of an interior wall was constructed using the new gypsum plaster blocks and a mortar of gypsum plaster and water, as shown in Figure 18. Buildings 2022, 12, 1297 15 of 17 Buildings 2022, 12, x FOR PEER REVIEW 16 of 18 Finally, a prototype of an interior wall was constructed using the new gypsum plaster blocks and a mortar of gypsum plaster and water, as shown in Figure 18. Figure Figure 18. 18. Steps Steps of of wall wall protot prototype ype constructio construction. n. The following conclusions were noted: The following conclusions were noted: The construction of the walls by the new blocks is very easy and very fast due to the • The construction of the walls by the new blocks is very easy and very fast due to the flat surfaces and to the similarity in size of blocks. flat surfaces and to the similarity in size of blocks. Compared with the ordinary brick blocks, the mortar consumption is considerably low. • Compared with the ordinary brick blocks, the mortar consumption is considerably The possibility of faience attachment was observed. low. There are no cracks observed at joints between blocks. • The possibility of faience attachment was observed. • There are no cracks observed at joints between blocks. 6. Conclusions This work presents the results of an experimental study on a new design of green 6. Conclusions gypsum plaster blocks with circular alveolar. This work presents the results of an experimental study on a new design of green The main conclusions of the experimental results are the following: gypsum plaster blocks with circular alveolar. - Gypsum plaster blocks have a tolerated dimensions after drying. The main conclusions of the experimental results are the following: - The flatness index shows that gypsum plaster blocks have a flat surface. ­ Gypsum plaster blocks have a tolerated dimensions after drying. - Gypsum plaster blocks can be considered as average density blocks because of their ­ The flatness index shows that gypsum plaster blocks have a flat surface. very low density. ­ Gypsum plaster blocks can be considered as average density blocks because of their - Gypsum plaster blocks have a recommended compressive strength for wall construction. very low density. - Gypsum plaster blocks have very quick setting. ­ Gypsum plaster blocks have a recommended compressive strength for wall con- - The construction of the walls by the new blocks is very easy and very fast due to the struction. flat surfaces and to the similarity in size of blocks. ­ Gypsum plaster blocks have very quick setting. - Because these gypsum blocks are very sensitive to water, they are not intended for ­ The construction of the walls by the new blocks is very easy and very fast due to the dry zones. flat surfaces and to the similarity in size of blocks. ­ Because these gypsum blocks are very sensitive to water, they are not intended for Author Contributions: Funding acquisition, H.Y.B.K. and W.J.K.; investigation, O.B.; supervision, dry zones. O.B.; visualization, N.M.; writing—original draft, O.B.; writing—review and editing, H.Y.B.K., W.J.K., O.B., and N.M. All authors have read and agreed to the published version of the manuscript. Author Contributions: Funding acquisition, H.Y.B.K. and W.J.K.; investigation, O.B.; supervision, Funding: This research was funded by [CENTRE OF EXCELLENCE] grant number [J510050002-IC- O.B.; visualization, N.M.; writing—original draft, O.B.; writing—review and editing, H.Y.B.K., 6BOLDREFRESH2025] and the APC was funded by [CENTRE OF EXCELLENCE]. W.J.K., O.B., and N.M. All authors have read and agreed to the published version of the manu- script. Institutional Review Board Statement: Not applicable. Funding: This research was funded by [CENTRE OF EXCELLENCE] grant number [J510050002-IC-6BOLDREFRESH2025] and the APC was funded by [CENTRE OF EXCELLENCE]. Institutional Review Board Statement: Not applicable. Buildings 2022, 12, 1297 16 of 17 Informed Consent Statement: Not applicable. Data Availability Statement: Not applicable. Acknowledgment: Acknowledgment to grant no.: J510050002-IC-6 BOLDREFRESH2025-CENTRE OF EXCELLENCE. Conflicts of Interest: The authors declare no conflict of interest. Collaborators: University Tenaga Nasional, Malaysia; Prince Sattam bin Abdulaziz University, Saudi Arabia; Curtin University, Australia. References 1. Morgan, D.J. Thermal analysis including evolved gas analysis of clay raw materials. Appl. Clay Sci. 1993, 8, 81–89. [CrossRef] 2. Santos, D.R.; Toledo, R.; Faria, R.T., Jr.; Carrio, J.G.; Da Silva, M.G.; Auler, L.T. Evolved gas analysis of clay materials. Rev. Sci. Instrum. 2003, 74, 663–666. [CrossRef] 3. Toledo, R.; dos Santos, D.R.; Faria, R.T., Jr.; Carrio, J.G.; Auler, L.T.; Vargas, H. Gas release during clay firing and evolution of ceramic properties. Appl. Clay Sci. 2004, 27, 151–157. [CrossRef] 4. Gonzalez, I.; Galan, E.; Miras, A.; Vazquez, M.A. CO emissions derived from raw materials used in brick factories. Applications to Andalusia (Southern Spain). Appl. Clay Sci. 2011, 52, 193–198. [CrossRef] 5. Cusido, J.A.; Cremades, L.V.; Gonzalez, M. Gaseous emissions from ceramics manufactured with urban sewage sludge during firing processes. Waste Manage. 2003, 23, 273–280. [CrossRef] 6. Mansour, B.M.; Soukaina, A.C.; Benhamou, B.; Jabrallah, B.S. Thermal characterization of a Tunisian gypsum plaster as Construc- tion Material. Energy Proc. 2013, 42, 680–688. [CrossRef] 7. Xamán, J.; Lira, L.; Arce, J. Analysis of the temperature distribution in a guarded hot plate apparatus for measuring thermal conductivity. Appl. Therm. Eng. 2009, 29, 617–623. [CrossRef] 8. Salmon, D. Thermal conductivity of insulations using guarded hot plates, including recent developments and source of reference materials. Meas. Sci. Technol. 2001, 12, 89–98. [CrossRef] 9. Fabio, S.M.; Renata, N.T. Infrared thermography applied to the quantitative determination of spatial and thermophysical parameters of hidden included objects. Appl. Therm. Eng. 2007, 27, 2378–2384. 10. Jannot, Y.; Zoubir, A. A quadrupolar complete model of the hot disc. Meas. Sci. Technol. 2007, 18, 1229–1234. [CrossRef] 11. Jannot, Y.; Meukam, P. Simplified estimation method for the determination of thermal effusivity and thermal conductivity with a low cost hot strip. Meas. Sci. Technol. 2004, 15, 1932–1938. [CrossRef] 12. Coquard, D.; Baillis, D.; Quenard, D. Experimental and theoretical study of the hot-wire method applied to low-density thermal insulators. Int. J. Heat Mass Transf. 2006, 49, 4511–4524. [CrossRef] 13. Koksal, F.; Gencel, O.; Kaya, M. Combined effect of silica fume and expanded vermiculite on properties of lightweight mortars at ambient and elevated temperatures. Constr. Build. Mater. 2015, 88, 175–187. [CrossRef] 14. Korjenic, A.; Zach, J.; Hroudová, J.; Petránek, V.; Korjenic, S.; Bednar, T. Development and optimization of advanced silicate plasters materials for building rehabilitation. In Proceedings of the 2nd Central European Symposium on Building Physics, Vienna, Austria, 9–11 September 2013; pp. 863–867. 15. Václavík, V.; Daxner, J.; Valícek, ˇ J.; Dvorský, T.; Kušnerová, M.; Harnic ˇárová, M.; Bendová, M.; Brenek, ˇ A. The use of industrial waste as a secondary raw material in restoration plaster with thermal insulating effect. Adv. Mat. Res. 2014, 897, 204–214. [CrossRef] 16. Vieira, J.; Senff, L.; Goncalves, H.; Silva, L.; Ferreira, V.M.; Labrincha, J.A. Functionalization of mortars for controlling the indoor ambient of buildings. Energ. Build. 2014, 70, 224–236. [CrossRef] 17. Hroudová, J.; Zach, J.; Hela, R.; Korjenic, A. Advanced, Thermal Insulation Materials Suitable for Insulation and Repair of Buildings. Adv. Mat. Res. 2013, 688, 54–59. [CrossRef] 18. Zach, J.; Korjenic, A.; Hroudová, J. Study of behaviour of advanced silicate materials for heating and moisture rehabilitation of buildings. Adv. Mat. Res. 2013, 649, 167–170. 19. Gencel, O.; Diaz, J.J.C.; Sutcu, M.; Koksal, F.; Rabanal, F.P.A.; Barrera, G.M.; Brostow, W. Properties of gypsum composites containing vermiculite and polypropylene fibers: Numerical and experimental result. Constr. Build. Mater. 2014, 70, 135–144. [CrossRef] 20. Khalil, A.A.; Tawfik, A.; Hegazy, A.A.; El-Shahal, M.F. Effect of some waste additives on the physical and mechanical properties of gypsum plaster composites. Constr. Build. Mater. 2014, 68, 580–586. [CrossRef] 21. Benazzouk, A.; Douzane, O.; Mezreb, K.; Laidoudi, B.; Queneudec, M. Thermal conductivity of cement composites containing rubber waste particles, experimental study and modelling. Constr. Build. Mater. 2008, 22, 573–579. [CrossRef] 22. NF P94-057; Soils Investingation and Testing. Granulometric Analysis. Hydrometer Method. May 1992. Available on- line: https://www.boutique.afnor.org/en-gb/standard/nf-p94057/soils-investingation-and-testing-granulometric-analysis- hydrometer-method/fa020768/11074#AreasStoreProductsSummaryView (accessed on 19 May 2022). 23. ASTM Standard D2487; Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). ASTM International: West Conshohocken, PA, USA, 2000. Buildings 2022, 12, 1297 17 of 17 24. NF EN 196; Methods of Testing Cements—Part 6: Determination of Fineness. 6 April 2012. Available online: https://www. boutique.afnor.org/en-gb/standard/nf-en-1966/methods-of-testing-cement-determination-of-fineness/fa187053/83194 (ac- cessed on 19 May 2022). 25. NF EN 1097-7; Tests for Mechanical and Physical Properties of Aggregates—Part 7: Determination of the Particle Density of Filler-Pyknometer Method. June 2008. Available online: https://www.boutique.afnor.org/en-gb/standard/nf-en-10977/tests- for-mechanical-and-physical-properties-of-aggregates-part-7-determina/fa155696/31162 (accessed on 19 May 2022). 26. NF EN 12390; Testing Hardened Concrete-Part4: Compression Strength-Specification for Testing Machines, European Committee for Standardization CEN: Brussels, Belgium, 2009. Available online: https://www.boutique.afnor.org/en-gb/results?Keywords= NF+EN+12390&StandardStateIds=1 (accessed on 19 May 2022). 27. Alyousef, R.; Benjeddou, O.; Soussi, C.; Khadimallah, M.A.; Jedidi, M. Experimental Study of New Insulation Lightweight Concrete Block Floor Based on Perlite Aggregate. Adv. Mater. Sci. Eng. 2019, 2019, 8160461. [CrossRef] 28. Ben Mansour, M.; Cherif, A.S.; Ben Jabrallah, S.; Benhamou, B. Caractérisation thermique d’un plâtre de gypse tunisien utilisé en tant que matériau de construction. In Proceedings of the EcoMAT2013, Ougadougou, Burkina Faso, 10–12 June 2013. 29. NF EN 12859; Gypsum Blocks-Definitions, Requirements and Test Methods. April 2011. Available online: https://www.boutique. afnor.org/en-gb/results?Keywords=NF+EN+12859&StandardStateIds=1 (accessed on 19 May 2022). 30. NF EN 772-21; Methods of Test for Masonry Units—Part 21: Determination of Water Absorption of Clay and Calcium Silicate Masonry Units by Cold Water Absorption. August 2011. Available online: https://www.boutique.afnor.org/en-gb/results? Keywords=NF+EN+772-21&StandardStateIds=1 (accessed on 19 May 2022). 31. NF EN ISO 8990; Thermal Insulation-Determination of Steady-State Thermal Transmission Properties-Calibrated and Guarded Hot Box. 1996. Available online: https://www.boutique.afnor.org/en-gb/results?Keywords=NF+EN+ISO+8990&StandardStateIds=1 (accessed on 19 May 2022). http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Buildings Multidisciplinary Digital Publishing Institute

Experimental Investigation of a New Design of Insulation Gypsum Plaster Blocks

Download PDF
17 pages

Loading next page...
 
/lp/multidisciplinary-digital-publishing-institute/experimental-investigation-of-a-new-design-of-insulation-gypsum-CKjaRwigyW
Publisher
Multidisciplinary Digital Publishing Institute
Copyright
© 1996-2022 MDPI (Basel, Switzerland) unless otherwise stated Disclaimer The statements, opinions and data contained in the journals are solely those of the individual authors and contributors and not of the publisher and the editor(s). MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Terms and Conditions Privacy Policy
ISSN
2075-5309
DOI
10.3390/buildings12091297
Publisher site
See Article on Publisher Site

Abstract

buildings Article Experimental Investigation of a New Design of Insulation Gypsum Plaster Blocks 1 , 1 2 , 3 Herda Yati Binti Katman * , Wong Jee Khai , Omrane Benjeddou * and Nuha Mashaan Institute of Energy Infrastructure, Universiti Tenaga National, Putrajaya Campus, Jalan IKRAM-UNITEN, Kajang 43000, Selangor, Malaysia Civil Engineering Department, College of Engineering, Prince SattamBin Abdulaziz University, Alkharj 16273, Saudi Arabia Department of Civil Engineering, School of Civil and Mechanical Engineering, Curtin University, Kent Street, Bentley, WA 6102, Australia * Correspondence: herda@uniten.edu.my (H.Y.B.K.); benjeddou.omrane@gmail.com (O.B.) Abstract: Green building materials are an alternative to ordinary materialsoffering multiple environ- mental benefits. This study consists of an experimental investigation of a new design of gypsum plaster blocks. First, a mix design of gypsum plaster and water mixture was prepared. The optimal mix composition was determined according to the mechanical and physical properties, such as the water absorption, the temperature of hydration, the density, and the compressive strength of different gypsum plaster and water mixtures made by varying the water dosage. The second part of this investigation aims to study a new design of green blocks prepared from the optimal water and gypsum plaster mixture. The new blocks are perforated to lighten them and to reduce their thermal conductivity in order to make them moreinsulate. Experimental tests were conducted on the block prototype, such as the measurement of dimensional tolerances, compressive strength, density, flatness, water absorption, residual moisture, surface hardness, and thermal conductivity. Experimental test results show that the new blocks have very low density, and their compressive strength is sufficient Citation: Binti Katman, H.Y.; Khai, for wall construction. In addition, the manufacturing process of the new blocks is very easy and very W.J.; Benjeddou, O.; Mashaan, N. Experimental Investigation of a New fast. Finally, the obtained physical and mechanical properties of the new gypsum plaster blocks give Design of Insulation Gypsum Plaster it the opportunity to be used for interior walls for building constructions. Blocks. Buildings 2022, 12, 1297. https://doi.org/10.3390/ Keywords: experimental investigation; energy; insulation; green; gypsum plaster; mixture; block buildings12091297 Academic Editors: Luca Pelà and Antonio Formisano 1. Introduction Received: 12 May 2022 The traditional fired clay bricks industry is a source of environmental pollution. This is Accepted: 10 August 2022 due to the high gas emissions into the atmosphere generated during the process of firing in Published: 24 August 2022 this industry [1]. In order to resolve this problem, little research has investigated reducing Publisher’s Note: MDPI stays neutral or controlling the gases evolved from the firing process of the clay bricks industry. In this with regard to jurisdictional claims in case, Santos et al. [2] and Toledo et al. [3] studied the correlations between clay properties published maps and institutional affil- and the amount of gas emissions as a function of the temperature of firing. On the other iations. hand, Gonzalez et al. [4] and Cusido et al. [5] show that the control of mineral contents of clay and the temperature during the firing process allows reducing gas emissions, especially fluorine, chlorine, and sulfur gases. Nowadays, researchers investigated new materials for the development of sustainable Copyright: © 2022 by the authors. green blocks. This aims first to decrease the traditional brick industry’s impacts on human Licensee MDPI, Basel, Switzerland. health and on the environment, and second, to reduce the high energy consumption of the This article is an open access article traditional brick industry. distributed under the terms and Gypsum plaster is one of materials providing many solutions to conventional ma- conditions of the Creative Commons terial problems. This is due to its interesting physical and mechanical properties, such Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ as low thermal conductivity, low density, and high firing resistance [6]. Many studies 4.0/). have investigated the improvement of the thermal insulation of gypsum plaster blocks for Buildings 2022, 12, 1297. https://doi.org/10.3390/buildings12091297 https://www.mdpi.com/journal/buildings Buildings 2022, 12, 1297 2 of 17 interior walls [7–12]. Other studies have investigated the incorporation of other natural raw materials and chemical additives in gypsum plaster blocks to improve their physical properties, especially the thermal conductivity and the density [13–17]. In the other case, the results of the works of Zach et al. [18], Korjenic et al. [14], and Hroudová et al. [17] show that the capillary activity of gypsum plaster blocks has a significant effect on the residual moisture of buildings. In addition, Gencel et al. [19], Khalil et al. [20], and Be- nazzouk et al. [21] show that the mechanical and physical properties of gypsum plaster mixture are improved by adding some additives’ waste to the mixtures. As an example, Gencel et al. [19] demonstrate that the sound-proofing property and thermal property of gypsum plaster mixture were improved by adding pore-forming agents. Finally, this study aims to explore the advantages of gypsum plaster mixture for developing a new design of gypsum plaster blocks perforated using circular alveolar. he holes perforated on blocks aim to lighten them and to reduce their thermal conductivity in order to make them more insulate. Notice that if the mechanical and physical properties of the new blocks verify the requirements of the international standards, they will be a good alternative for the con- struction of buildings interior walls with high thermal insulation. The first part of this study consists of studying both the physical and chemical proper- ties of the used gypsum plaster. The second part aims to elaborate an optimal mix design of gypsum plaster and water mortar. The second parts consists of evaluating both the physical and mechanical properties of the optimal mixture. The third part aims to validate the possibility of use of perforated gypsum plaster as an ecological green block by experimental tests on the newly designed block prototypes. 2. Experimental Program The objective of this work is the development of new perforated blocks using gypsum plaster and water mixture. The experimental study flow chart representing all conducted experiment tests is shown in Figure 1. The main parts of this experimental study are the following: - Evaluate the chemical, physical, and mineral properties of the gypsum plaster used in this study, such as: Chemical composition using an X-ray fluorescence spectrometry (XRF). Microstructure analysis by scanning electron microscope. Particle size analysis. Densities. Blaine specific surface (BSS). - Mix design of gypsum plaster and water mixture in order to determine the optimal mixture composition. - Study of the mechanical and the physical properties of gypsum and water mixture, such as: Density. Water absorption. Temperature of hydration. Compressive strength. - Preparation of the block prototypes. - Study of the mechanical and the physical properties of gypsum plaster block prototype: Dimensional tolerances. Density. Compressive strength. Flatness. Residual moisture. Water absorption. Surface hardness. Buildings 2022, 12, x FOR PEER REVIEW 3 of 18 Buildings 2022, 12, 1297 3 of 17 • Residual moisture. • Water absorption. • Surface hardness. • Therma Thermal l conducti conductivity vity. . Figure 1. Experimental study flow chart. Figure 1. Experimental study flow chart. 3. Materials and Methods 3. Materials and Methods 3.1. Gypsum Plaster 3.1. Gypsum Plaster 3.1.1. Chemical Analysis 3.1.1. Chemical Analysis Gypsum plaster used in this work is a local product. The chemical analysis was Gypsum plaster used in this work is a local product. The chemical analysis was performed by an X-ray fluorescence spectrometry (XRF). This test consists of evaluating the performed by an X-ray fluorescence spectrometry (XRF). This test consists of evaluating content in percent of Al O , CaO, F O , K O, MgO, Na O, SiO and SO . The chemical 2 3 e2 3 2 2 2, 3 the content in percent of Al2O3, CaO, Fe2O3, K2O, MgO, Na2O, SiO2, and SO3. The chemical analysis result of gypsum plaster is presented in Table 1. Result shows that the tested analysis result of gypsum plaster is presented in Table 1. Result shows that the tested gypsum plaster is too rich in calcium oxide (CaO  35%) and in sulfur dioxide (SO  47%). 3 Buildings 2022, 12, x FOR PEER REVIEW 4 of 18 Buildings 2022, 12, 1297 4 of 17 gypsum plaster is too rich in calcium oxide (CaO ≈ 35%) and in sulfur dioxide (SO3 ≈ 47%). Table 1. Gypsum plaster chemical composition. Table 1. Gypsum plaster chemical composition. Component Al O CaO Fe O K2O MgO Na O SO SiO 2 3 2 3 2 3 2 Component Al2O3 CaO Fe2O3 K2O MgO Na2O SO3 SiO2 Percentage 0.10 34.85 0.08 0.03 0.53 0.09 46.63 0.70 Percentage 0.10 34.85 0.08 0.03 0.53 0.09 46.63 0.70 3.1.2. Microstructure Analysis by Scanning Electron Microscope 3.1.2. Microstructure Analysis by Scanning Electron Microscope The morphological forms of the used gypsum plaster were studied using a scanning The morphological forms of the used gypsum plaster were studied using a scanning Electron Microscope (SEM). Results of SEM image, presented in Figure 2, show that al- Electron Microscope (SEM). Results of SEM image, presented in Figure 2, show that al- most all plaster grains have a spherical shape, which means that this gypsum plaster is most all plaster grains have a spherical shape, which means that this gypsum plaster is highly semihydrated. highly semihydrated. Figure 2. SEM image of marble paste (×10,000). Figure 2. SEM image of marble paste (10,000). 3.1.3. Particle Size Analysis 3.1.3. Particle Size Analysis The distribution of gypsum plaster grain size was carried out using the sedimentation The distribution of gypsum plaster grain size was carried out using the sedimenta- method according to NF P 94-057 [22] standard requirements. tion method according to NF P 94-057 [22] standard requirements. Figure 3 shows the curve the distribution of the particle size of gypsum plaster. Figure 3 shows the curve the distribution of the particle size of gypsum plaster. According to this curve, the fineness modulus is about 0.95, which means that the tested According to this curve, the fineness modulus is about 0.95, which means that the tested plaster is very fine. plaster is very fine. Two other important factors, characterizing grains size distribution, are determined: the curvature coefficient (C ) and the uniformity coefficient (C ). C and C are expressed c u c u as follow [23]: D D 30 30 C = (1) D D 10 60 C = (2) where D , D , and D are the grain size at 10%, 30%, and 60% passing, respectively. 10 30 60 Test results indicate that C and C of the used gypsum plaster are, respectively, 5.6 u c and 1.6. Indeed, due to C > 2 and 1 < C < 3, it can be concluded that the gypsum plaster u c is effectively graded and graduated. Buildings 2022, 12, 1297 5 of 17 Buildings 2022, 12, x FOR PEER REVIEW 5 of 18 0.001 0.01 0.1 1 0,001 0,01 0,1 1 Diameter (mm) Figure 3. Particle size distribution of gypsum plaster. Figure 3. Particle size distribution of gypsum plaster. Two other important factors, characterizing grains size distribution, are determined: 3.1.4. Physical Properties the curvature coefficient (Cc) and the uniformity coefficient (Cu). Cc and Cu are expressed Table 2 presents the physical properties of gypsum plaster. Tests results demonstrate as follow [23]: that gypsum plaster has a bulk density and an absolute density equal to 0.60 g/cm and 2.65 g/cm , respectively. Results also show that D.D the Blaine specific surface (BSS) of gypsum 30 30 C = 2 (1) plaster, determined using the NF EN 196-6 [24] requirements, is about 5705 cm /g. This D.D 10 60 result confirms that gypsum plaster used in this study is very fine. (2) C = Table 2. Physical properties of gypsum plaster. where D10, D30, and D Absolute 60 are th Density e grain size at 10%, 30%, and 60% passing, resp Blaine Specific ectively. Surface Parameters Particle Size (mm) Bulk Density (g/cm ) 3 2 (g/cm ) (BSS) (cm /g) Test results indicate that Cu and Cc of the used gypsum plaster are, respectively, 5.6 and 1.6. Indeed, due to Cu > 2 and 1 < Cc < 3, it can be concluded that the gypsum plaster is Standard NF P 94-056 [22] NF EN 1097-7 [25] NF EN 196-6 [24] effectively graded and graduated. Test result 0/0.5 2.65 0.60 5705 3.1.4. Physical Properties 3.2. Tests Setup on Gypsum Plaster and Water Mixture Table 2 presents the physical properties of gypsum plaster. Tests results demon- 3.2.1. Mix Design of the Mixture strate that gypsum plaster has a bulk density and an absolute density equal to 0.60 g/cm and 2.65 g/cm , respectively. Results also show that the Blaine specific surface (BSS) of The objective of this part is to evaluate the mix design of the gypsum plaster and gypsum plaster, determined using the NF EN 196-6 [24] requirements, is about 5705 water mixture. The appropriate water volume is that given a workability that makes the cm /g. This result confirms that gypsum plaster used in this study is very fine. mixture molding without any vibration process easy. To perform this, different mixtures are prepared by varying the water/gypsum plaster ratio, and thereafter their flow times Table 2. Physical properties of gypsum plaster. were measured by using an LCL mortar maniabilimeter (Figure 4). The flow time Partic measur le Size ements Absolute results Densi are tpr y esented Bulk Densi- in Table Blaine Sp 3 and in ecif Figur ic Sur e 4 -. The Parameters 3 3 2 presented results show that the flow time decreases when increasing the water amount. In (mm) (g/cm ) ty(g/cm ) face (BSS) (cm /g) addition, results of Figure 5 show that until a water/gypsum plaster ratio of 0.60, the flow Standard NF P 94-056 [22] NF EN 1097-7 [25] NF EN 196-6 [24] times of the mixtures remain constant, and thereafter the workability of these mixtures Test result 0/0.5 2.65 0.60 5705 is the same. As a conclusion, the water amount is chosen as equal to 60% of the gypsum plaster amount. 3.2. Tests Setup on Gypsum Plaster and Water Mixture 3.2.1. Mix Design of the Mixture Cumulative (%) Buildings 2022, 12, x FOR PEER REVIEW 6 of 18 Buildings 2022, 12, x FOR PEER REVIEW 6 of 18 The objective of this part is to evaluate the mix design of the gypsum plaster and water mixture. The appropriate water volume is that given a workability that makes the mixture molding without any vibration process easy. To perform this, different mixtures The objective of this part is to evaluate the mix design of the gypsum plaster and are prepared by varying the water/gypsum plaster ratio, and thereafter their flow times water mixture. The appropriate water volume is that given a workability that makes the were measured by using an LCL mortar maniabilimeter (Figure 4). mixture molding without any vibration process easy. To perform this, different mixtures Buildings 2022, 12, 1297 6 of 17 are prepared by varying the water/gypsum plaster ratio, and thereafter their flow times were measured by using an LCL mortar maniabilimeter (Figure 4). Figure 4. Measurement of flow time using LCL mortar maniabilimeter. The flow time measurements results are presented in Table 3 and in Figure 4. The presented results show that the flow time decreases when increasing the water amount. In addition, results of Figure 5 show that until a water/gypsum plaster ratio of 0.60, the Figure 4. Measurement of flow time using LCL mortar maniabilimeter. Figure 4. Measurement of flow time using LCL mortar maniabilimeter. flow times of the mixtures remain constant, and thereafter the workability of these mix- tures is the same. As a conclusion, the water amount is chosen as equal to 60% of the T gyp able sum The flow 3. p Results laster am tim of flow oe u measureme nttime . measur nements ts results test.are presented in Table 3 and in Figure 4. The presented results show that the flow time decreases when increasing the water amount. Table 3. Results of flow time measurements test. Water/Gypsum plaster 0.54 0.58 0.59 0.60 0.61 0.62 0.63 0.64 In addition, results of Figure 5 show that until a water/gypsum plaster ratio of 0.60, the Flow time (s) flow times of the mixtures remain const 5.23 4.53 3.41 2.38 ant, and ther 1.99 eafter the wo 1.75 rkability 1.55 of these mix- 1.49 Water/Gypsum plaster 0.54 0.58 0.59 0.60 0.61 0.62 0.63 0.64 tures is the same. As a conclusion, the water amount is chosen as equal to 60% of the Flow time (s) 5.23 4.53 3.41 2.38 1.99 1.75 1.55 1.49 gypsum plaster amount. Table 3. Results of flow time measurements test. Water/Gypsum plaster 0.54 0.58 0.59 0.60 0.61 0.62 0.63 0.64 Flow time (s) 5.23 4.53 3.41 2.38 1.99 1.75 1.55 1.49 1 4 0.52 0.54 0.56 0.58 0.60 0.62 0.64 0.66 0,52 0,54 0,56 0,58 0,6 0,62 0,64 0,66 Water/Gypsum plaster Figure 5. Flow time as function of water/gypsum plaster ratio. Figure 5. Flow time as function of water/gypsum plaster ratio. 3.2.2. Test Specimens Preparation 3.2.2. Test Specimens Preparation In this experimental study, cubic and cylindrical specimens are manufactured using a gypsum plaster and 60% water mixture. The dimensions and the number of each specimen 0.52 0.54 0.56 0.58 0.60 0.62 0.64 0.66 0,52 0,54 0,56 0,58 0,6 0,62 0,64 0,66 shape per test are shown in Table 4. Water/Gypsum plaster Table 4. Specimens shape and dimensions. Figure 5. Flow time as function of water/gypsum plaster ratio. Test Specimen Shape Specimen Dimensions Number of SpecimensbyTest 3.2.2. Test Specimens Preparation Density Cubic 100  100  100 mm 3 Absorption degree Cubic 100  100  100 mm 3 Hydration temperature Cubic 100  100  100 mm 3 Compressive strength Cylindrical 50  100 mm 12 The mixing process of gypsum plaster and water mixture are the following: Flow time [s] Flow time [s] Buildings 2022, 12, x FOR PEER REVIEW 7 of 18 In this experimental study, cubic and cylindrical specimens are manufactured using a gypsum plaster and 60% water mixture. The dimensions and the number of each specimen shape per test are shown in Table 4. Table 4. Specimens shape and dimensions. Test Specimen Shape Specimen Dimensions Number of SpecimensbyTest Density Cubic 100×100 × 100 mm 3 Absorption degree Cubic 100 × 100 × 100 mm 3 Hydration temperature Cubic 100 × 100 × 100 mm 3 Buildings 2022 Compr , 12, 1297 essive strength Cylindrical 50 × 100 mm 12 7 of 17 The mixing process of gypsum plaster and water mixture are the following: n Add the gypsum plaster amount to 60% water (Figure 6a).  Add the gypsum plaster amount to 60% water (Figure 6a). n Mix in wet condition first for 30 s with slow speed and then for 1 min with high speed  Mix in wet condition first for 30 s with slow speed and then for 1 min with high (Figure 6b). speed (Figure 6b). n Prepare the molds (Figure 6c,d).  Prepare the molds (Figure 6c,d). n Pour the mixture on the molds (Figure 6e).  Pour the mixture on the molds (Figure 6e). n Dry the specimens for 10 min before demolding (Figure 6f,g).  Dry the specimens for 10 min before demolding (Figure 6f,g). n Demold the specimens (Figure 6h).  Demold the specimens (Figure 6h). n Finally, keep specimens under a temperature degree of 23 C and a relative humidity  Finally, keep specimens under a temperature degree of 23 °C and a relative humid- between 55 and 65% to the testing date. ity between 55 and 65% to the testing date. Figure 6. Steps of specimens’ preparation process :(a) Add the gypsum plaster to water, (b) Mix in Figure 6. Steps of specimens’ preparation process: (a) Add the gypsum plaster to water, wet condition, (c,d) Molds preparation, (e) Molds casting, (f,g) Specimens drying, (h) Specimens (b) Mix in wet condition, (c,d) Molds preparation, (e) Molds casting, (f,g) Specimens drying, demolding (h) Specimens demolding. 3.2.3. Density 3.2.3. Density Buildings 2022, 12, x FOR PEER REVIEW 8 of 18 Density measurements consist, as presented in Figure 7, of weighting a cubic specimen Density measurements consist, as presented in Figure 7, of weighting a cubic as a function of time until its mass is stabilized. specimen as a function of time until its mass is stabilized. Figure 7. Density measurement process. Figure 7. Density measurement process. 3.2.4. Water Absorption Degree This test consists of measuring the mass of water absorbed by a cubic specimen of gypsum plaster and water mixture as a function of time. Measurement process steps, presented in Figure 8, consist of weighting the sample both in its dry state and in its wet state. Figure 8. Measurement of specimen absorption degree. 3.2.5. Temperature of Hydration Measurement of the hydration temperature of gypsum plaster and water mixture steps are as follows:  Prepare an insulating cubic mold (Figure 9a).  Pour the mixture on the molds (Figure 9b).  Place a thermometer in a copper tube containing oil in the specimen center (Figure 9c).  Measure hydration temperature with time.  Measure the ambient temperature using another thermometer. Buildings 2022, 12, x FOR PEER REVIEW 8 of 18 Buildings 2022, 12, x FOR PEER REVIEW 8 of 18 Buildings 2022, 12, 1297 8 of 17 Figure 7. Density measurement process. Figure 7. Density measurement process. 3.2.4. Water Absorption Degree 3.2.4. Water Absorption Degree 3.2.4. Water Absorption Degree This This test te st cons cons ist ist s sof of me meas asu ur ring ing t th he m e m aa sss of s of w w ater ater ab ab sorbed by sorbed by a c ua c bicu spec bic spec imenime of n of This test consists of measuring the mass of water absorbed by a cubic specimen of gypsum plaster and water mixture as a function of time. Measurement process steps, gypsum plaster and water mixture as a function of time. Measurement process steps, gypsum plaster and water mixture as a function of time. Measurement process steps, presented in Figure 8, consist of weighting the sample both in its dry state and in its wet presented in Figure 8, consist of weighting the sample both in its dry state and in its wet presented in Figure 8, consist of weighting the sample both in its dry state and in its state. state. wet state. Figure 8. Measurement of specimen absorption degree. Figure 8. Measurement of specimen absorption degree. Figure 8. Measurement of specimen absorption degree. 3.2.5. Temperature of Hydration Measurement of the hydration temperature of gypsum plaster and water mixture 3.2.5. Temperature of Hydration 3.2.5. Temperature of Hydration steps are as follows: Measurement of the hydration temperature of gypsum plaster and water mixture Measurement of the hydration temperature of gypsum plaster and water mixture  Prepare an insulating cubic mold (Figure 9a). steps are as follows: steps are as follows:  Pour the mixture on the molds (Figure 9b). n Prepare an insulating cubic mold (Figure 9a).  Place a thermometer in a copper tube containing oil in the specimen center (Figure  Prepare an insulating cubic mold (Figure 9a). n Pour the mixture on the molds (Figure 9b). 9c).  Pour the mixture on the molds (Figure 9b). n Place a thermometer in a copper tube containing oil in the specimen center (Figure 9c).  Measure hydration temperature with time.  n Place a t Measur he erm hydration ometer in a c temperatur oppe er t with ubtime. e containing oil in the specimen center (Figure  Measure the ambient temperature using another thermometer. n Measure the ambient temperature using another thermometer. 9c).  Measure hydration temperature with time.  Measure the ambient temperature using another thermometer. Figure 9. Measurement of hydration temperature: (a) Preparation of insulating cubic mold, (b) Molds casting, (c) Thermometer placing. 3.2.6. Compressive Strength Compressive strength tests are carried out on cylindrical specimens of gypsum plaster mixture at the ages of 1, 3, 5, 7, 14, 21, and 28 days. Compressive tests were carried out using a UTM machine according to the requirements of EN 12390-4 [26] standard. 4. Properties of Gypsum Plaster and Water Mixture 4.1. Density The density measurement results of gypsum plaster and water mixture are presented in Table 5. Results show that the initial density, measured just after removing the specimen, 3, is about 1.711 g/cm and the stabilized density, measured after specimen mass stabilization, is about 1.278 g/cm . Indeed, the total water loss is about 25.30% of the initial weight. Buildings 2022, 12, x FOR PEER REVIEW 9 of 18 Figure 9. Measurement of hydration temperature : (a) Preparation of insulating cubic mold, (b) Molds casting, (c) Thermometer placing 3.2.6. Compressive Strength Compressive strength tests are carried out on cylindrical specimens of gypsum plaster mixture at the ages of 1, 3, 5, 7, 14, 21, and 28 days. Compressive tests were carried out using a UTM machine according to the requirements of EN 12390-4 [26] standard. 4. Properties of Gypsum Plaster and Water Mixture 4.1.Density The density measurement results of gypsum plaster and water mixture are pre- sented in Table 5. Results show that the initial density, measured just after removing the Buildings 2022, 12, 1297 9 of 17 3, specimen, is about 1.711 g/cm and the stabilized density, measured after specimen mass stabilization, is about 1.278 g/cm . Indeed, the total water loss is about 25.30% of the ini- tial weight. Figure 10 presents the density of mixture and time relationship. Two conclusions are Table 5. Physical properties of gypsum plaster specimen. deduced from this result: first, the density of specimen decreases with time, and second, the weight of the specimen was stabilized after 16 days, which is the end of the hardening Final Density Degree of Absorption Initial Density (g/cm ) Water Loss (%) (g/cm ) (%) step. Finally, a final density of 1.278 g/cm classifies the gypsum plaster blocks as 1.711 1.278 25.30 24.3 high-density building materials [27]. Table 5. Physical properties of gypsum plaster specimen. Figure 10 presents the density of mixture and time relationship. Two conclusions are deduced from this result: first, the density of specimen decreases with time, and second, the 3 3 Initial Density (g/cm ) Final Density (g/cm ) Water Loss (%) Degree of Absorption (%) weight of the specimen was stabilized after 16 days, which is the end of the hardening step. 1.711 1.278 25.30 24.3 0 2 4 6 8 10 1214 161820 Time (Days) Figure 10. Gypsum plaster density as function of time. Figure 10. Gypsum plaster density as function of time. 4.2. Degree of Absorption Finally, a final density of 1.278 g/cm classifies the gypsum plaster blocks as high- The results presented in Table 5 show that the maximum water absorption of gyp- density building materials [27]. sum plaster specimen is about 24.3%. The curve presented in Figure 11 shows the ab- sorption degree and time relationship. It can be concluded that the absorption degree of 4.2. Degree of Absorption the specimen increases with time, and the maximum absorption degree was reached after The results presented in Table 5 show that the maximum water absorption of gypsum 25 h. Results also show that 50% of the maximum degree of absorption was reached plaster specimen is about 24.3%. The curve presented in Figure 11 shows the absorption during only the three first hours. degree and time relationship. It can be concluded that the absorption degree of the specimen increases with time, and the maximum absorption degree was reached after 25 h. Results Buildings 2022, 12, x FOR PEER REVIEW 10 of 18 also show that 50% of the maximum degree of absorption was reached during only the three first hours. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (h) Figure 11. Specimen absorption degree as a function of time. Figure 11. Specimen absorption degree as a function of time. 4.3. Temperature of Hydration The curve of temperature of gypsum plaster and water specimen as a function of time is presented in Figure 12. The first remark observed from this curve is that the maximum temperature of the mixture is about 47°C, reached during the first 25 min. The second remark is that the setting of mixture due to the hydration reaction is very quick. Indeed, setting begins only after 10 min and finishes after nearly 25 min. As a conse- quence, a quick block removing is possible. 0 20406080 100 120 140 160 180 200 Time (min) Figure 12. Temperature of gypsum plaster and water specimen versus time. 4.4. Compressive Strength The compressive strength results at the ages of 1, 3, 5, 7, 14, 21, and 28 days are presented in Table 6. Results show that the maximum strength of gypsum plaster and water specimen, of about 11.2 MPa, was reached after 21 days. In addition, 50% of its maximum compression strength was reached only after one day. Figure 13 shows the curve of the compressive strength as function of strain after weight stabilization. According to this curve, it can be concluded that the gypsum plaster specimen has a nonlinear elastic behavior. Temperature (°C) Degree of absorption (%) Density (kg/m ) Buildings 2022, 12, x FOR PEER REVIEW 10 of 18 Buildings 2022, 12, 1297 10 of 17 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (h) Figure 11. Specimen absorption degree as a function of time. 4.3. Temperature of Hydration The curve of temperature of gypsum plaster and water specimen as a function of time 4.3. Temperature of Hydration is presented in Figure 12. The first remark observed from this curve is that the maximum The curve of temperature of gypsum plaster and water specimen as a function of temperatur time is presented i e of the n Figure mixtur 12. The e is about first rema 47rk observed C, reached from during this curve theisfirst that the 25 min. The second maximum temperature of the mixture is about 47°C, reached during the first 25 min. The remark is that the setting of mixture due to the hydration reaction is very quick. Indeed, second remark is that the setting of mixture due to the hydration reaction is very quick. setting begins only after 10 min and finishes after nearly 25 min. As a consequence, a quick Indeed, setting begins only after 10 min and finishes after nearly 25 min. As a conse- block removing is possible. quence, a quick block removing is possible. 0 20406080 100 120 140 160 180 200 Time (min) Figure 12. Temperature of gypsum plaster and water specimen versus time. Figure 12. Temperature of gypsum plaster and water specimen versus time. 4.4. Compressive Strength 4.4. Compressive Strength The compressive strength results at the ages of 1, 3, 5, 7, 14, 21, and 28 days are The compressive strength results at the ages of 1, 3, 5, 7, 14, 21, and 28 days are presented in Table 6. Results show that the maximum strength of gypsum plaster and water specimen, of about 11.2 MPa, was reached after 21 days. In addition, 50% of its presented in Table 6. Results show that the maximum strength of gypsum plaster and water maximum compression strength was reached only after one day. specimen, of about 11.2 MPa, was reached after 21 days. In addition, 50% of its maximum Figure 13 shows the curve of the compressive strength as function of strain after compression strength was reached only after one day. weight stabilization. According to this curve, it can be concluded that the gypsum plaster specimen has a nonlinear elastic behavior. Table 6. Compressive strength tests results. Buildings 2022, 12, x FOR PEER REVIEW 11 of 18 Age [day] 1 3 5 7 14 21 28 Compressive strength [MPa] 6.7 6.7 6.7 6.5 8.5 11.1 11.2 Table 6. Compressive strength tests results. Figure 13 shows the curve of the compressive strength as function of strain after Age [day] 1 3 5 7 14 21 28 weight stabilization. According to this curve, it can be concluded that the gypsum plaster Compressive strength [MPa] 6.7 6.7 6.7 6.5 8.5 11.1 11.2 specimen has a nonlinear elastic behavior. 0 0.1 0.2 0.3 0.4 0 0,1 0,2 0,3 0,4 Strain (%) Figure 13. Compressive strength–strain curve of gypsum plaster mixture after weight stabilization. Figure 13. Compressive strength–strain curve of gypsum plaster mixture after weight stabilization. 5. Design of New Gypsum Plaster Blocks 5.1. New Blocks Description A new design of blocks made using a water and gypsum plaster mixture was de- veloped. As it is known, the manufacturing process of gypsum plaster blocks is low en- ergy consumption compared with that of ordinary clay fired bricks [5]. In addition, fired bricks are an important source of atmospheric pollution [4]. According to the new design presented in Figure 14, the new blocks are 600 mm in length, 550 mm in height, and 100 mm in thickness. In addition, the new blocks are equipped with a circular alveolar system of 60 mm in diameter. The circular alveolar gives to the gypsum plaster blocks both a high thermal insula- tion and phonic insulation and a high compressive strength. Moreover, gypsum plaster makes the new blocks good hygrometric regulators, which means that they regulate in- ternal humidity by rejecting it outside the room or by absorbing it. Moreover, as known, gypsum plaster blocks have high fire resistance [28]. Finally, the new design of gypsum plaster blocks makes them an important alterna- tive for the construction of interior walls of buildings. Temperature (°C) Degree of absorption (%) Compressive strenght (MPa) Buildings 2022, 12, 1297 11 of 17 5. Design of New Gypsum Plaster Blocks 5.1. New Blocks Description A new design of blocks made using a water and gypsum plaster mixture was devel- oped. As it is known, the manufacturing process of gypsum plaster blocks is low energy consumption compared with that of ordinary clay fired bricks [5]. In addition, fired bricks are an important source of atmospheric pollution [4]. According to the new design presented in Figure 14, the new blocks are 600 mm Buildings 2022, 12, x FOR PEER REVIEW 12 of 18 in length, 550 mm in height, and 100 mm in thickness. In addition, the new blocks are equipped with a circular alveolar system of 60 mm in diameter. Figure 14. Perforated gypsum plaster blocks design. Figure 14. Perforated gypsum plaster blocks design. 5.2. Manufacturing of Gypsum Plaster Block Prototypes The circular alveolar gives to the gypsum plaster blocks both a high thermal insulation and phonic As shown i insulation n Figure 14 and , athe high block compr prototypes essive str ha ength. ve 100 Mor mm × eover 55,0 mm gypsum × 60plaster 0 mm di makes - mensions. the new blocks good hygrometric regulators, which means that they regulate internal The different steps for preparing the block prototypes are the following [29]: humidity by rejecting it outside the room or by absorbing it. Moreover, as known, gypsum plaster blocks have high fire resistance [28].  Prepare the steel mold (Figure 15a). Finally, the new design of gypsum plaster blocks makes them an important alternative  Place the mixture on the mold (Figure 15b). for the construction of interior walls of buildings.  Remove the blocks from the molds after 24 h (Figure 15c).  Dry the blocks on air (Figure 15d). 5.2. Manufacturing of Gypsum Plaster Block Prototypes Finally, the following experimental tests were carried out on the hardened blocks: As shown in Figure 14, the block prototypes have 100 mm  550 mm  600 mm ­ Dimensional tolerances. dimensions. ­ Density. The different steps for preparing the block prototypes are the following [29]: ­ Surface hardness. n Prepare the steel mold (Figure 15a). ­ Residual moisture. n Place the mixture on the mold (Figure 15b). ­ Thermal conductivity. n Remove the blocks from the molds after 24 h (Figure 15c). ­ Compressive strength. ­n Flatne Dry the ss. blocks on air (Figure 15d). Buildings 2022, 12, x FOR PEER REVIEW 13 of 18 Buildings 2022, 12, 1297 12 of 17 Figure 15. The block prototype manufacturing process : (a) Preparation of the steel mold, (b) Mold Figure 15. The block prototype manufacturing process: (a) Preparation of the steel mold, (b) Mold casting, (c) Blocks removing, (d) On air block drying casting, (c) Blocks removing, (d) On air block drying. 5.3. Properties of Gypsum Plaster Blocks Finally, the following experimental tests were carried out on the hardened blocks: 5. - 3.1. D Dimensional imensional Tol tolerances. erances - Density. After hardening, blocks will be expanded due to the hydration of gypsum plaster - Surface hardness. with water and, as consequence, block dimensions increase. he specifications of the - Residual moisture. standard NF EN 12859 [29] show that the maximum accepted tolerances in dimension - Thermal conductivity. change are ±5 mm for length, ±0.5 mm for thickness, and ±2 mm for height. - Compressive strength. The results of Table 7 show that after removing gypsum plaster blocks, their di- - Flatness. mensions increased to 100.3 mm, 550.7 mm, and 600.2 mm for thickness, height, and length, respectively. As a conclusion, the increases in block dimensions are lower than 5.3. Properties of Gypsum Plaster Blocks the maximum recommended tolerances. 5.3.1. Dimensional Tolerances After hardening, blocks will be expanded due to the hydration of gypsum plaster with Table 7. Mechanical and physical properties of gypsum plaster blocks. water and, as consequence, block dimensions increase. he specifications of the standard Property Result NF EN 12859 [29] show that the maximum accepted tolerances in dimension change are Length 600.2 5 mm for length, 0.5 mm for thickness, and 2 mm for height. Dimensional tolerances (mm) Height 550.7 The results of Table 7 show that after removing gypsum plaster blocks, their dimen- sions increased to 100.3 mm, 550.7 mm, and 600.2 mm for thickness, height, and length, Thickness 100.3 respectively. As a conclusion, the increases in block dimensions are lower than the maxi- Drying time (h) 48 mum recommended tolerances. Flatness (mm) 0.5 Density (Kg/m ) 856 Compressive strength (MPa) 5.6 Residual moisture (%) 5 Water absorption (%) 24.3 Surface hardness (shore C) 35 Thermal conductivity (W/mK) 0.45 Buildings 2022, 12, 1297 13 of 17 Table 7. Mechanical and physical properties of gypsum plaster blocks. Property Result Length 600.2 Dimensional tolerances (mm) Height 550.7 Thickness 100.3 Drying time (h) 48 Flatness (mm) 0.5 Density (Kg/m ) 856 Compressive strength (MPa) 5.6 Residual moisture (%) 5 Water absorption (%) 24.3 Buildings 2022, 12, x FOR PEER REVIEW 14 of 18 Surface hardness (shore C) 35 Thermal conductivity (W/mK) 0.45 5.3.2. Flatness 5.3.2. Flatness The specifications of the standard NF EN 12859 [29] show that the maximum devia- The specifications of the standard NF EN 12859 [29] show that the maximum deviation tion of metal ruler placed along the diagonals of the block and the shims must not exceed of metal ruler placed along the diagonals of the block and the shims must not exceed 1 mm. 1 mm. A flatness test made on the block prototypes (Figure 16) showed that its flatness A flatness test made on the block prototypes (Figure 16) showed that its flatness index is index is about 0.5 mm (Table 7). This flatness index is lower than the maximum recom- about 0.5 mm (Table 7). This flatness index is lower than the maximum recommended mended value of 1 mm. value of 1 mm. Figure 16. Flatness of the new gypsum plaster blocks. Figure 16. Flatness of the new gypsum plaster blocks. 5.3.3. Density 5.3.3. Density The results of Table 7 show that the density of the gypsum plaster block is about The results of Table 7 show that the density of the gypsum plaster block is about 856 856 kg/m . As a consequence, gypsum plaster blocks can be considerate as average kg/m . As a consequence, gypsum plaster blocks can be considerate as average density density blocks. blocks. 5.3.4. Compressive Strength 5.3.4. Compressive Strength The results of Table 7 show that the average compressive strength of gypsum plaster The results of Table 7 show that the average compressive strength of gypsum plaster blocks is about 5.6 MPa. This compressive strength value makes possible the use of these blocks is about 5.6 MPa. This compressive strength value makes possible the use of these blocks as building materials for interior walls [27]. blocks as building materials for interior walls [27]. 5.3.5. Residual Moisture 5.3.5. Residual Moisture The residual moisture content of the blocks was determined by weighting the block The residual moisture content of the blocks was determined by weighting the block after it was dried until the stabilization of weight at a temperature of 20  5 C in a after it was dried until the stabilization of weight at a temperature of 20±5 °C in a venti- ventilated room under relative humidity of 65  5% [28]. Results demonstrate that the lated room under relative humidity of 65 ± 5% [28]. Results demonstrate that the average average moisture content of the gypsum plaster block prototype is about 5%. This obtained moisture content of the gypsum plaster block prototype is about 5%. This obtained result result is lower than the maximum recommended value of 6% [28]. is lower than the maximum recommended value of 6% [28]. 5.3.6. Water Absorption The measurement of the degree of water absorption of gypsum plaster blocks was performed in accordance with NF EN 772-21 requirements [30]. The results of Table 7 show the water absorption degree of gypsum plaster blocks is about 24.4%. 5.3.7. Surface Hardness The hardness of blocks surface was measured, using a durometer, on dried blocks. Experimental results show that the hardness of the gypsum plaster blocks surface is about 35 (Table 7). Consequently, the class of the prepared gypsum plaster blocks is as low-density bricks. 5.3.8. Thermal Conductivity The thermal conductivity of gypsum plaster bricks was carried out with the speci- fications of NF EN ISO 8990 standard [31] by using the “boxes method”. The process of this method is presented in Figure 17. Results of Table 7 show that gypsum plaster blocks Buildings 2022, 12, 1297 14 of 17 5.3.6. Water Absorption The measurement of the degree of water absorption of gypsum plaster blocks was performed in accordance with NF EN 772-21 requirements [30]. The results of Table 7 show the water absorption degree of gypsum plaster blocks is about 24.4%. 5.3.7. Surface Hardness The hardness of blocks surface was measured, using a durometer, on dried blocks. Experimental results show that the hardness of the gypsum plaster blocks surface is about 35 (Table 7). Consequently, the class of the prepared gypsum plaster blocks is as low-density bricks. 5.3.8. Thermal Conductivity Buildings 2022, 12, x FOR PEER REVIEW 15 of 18 The thermal conductivity of gypsum plaster bricks was carried out with the spec- ifications of NF EN ISO 8990 standard [31] by using the “boxes method”. The process of this method is presented in Figure 17. Results of Table 7 show that gypsum plas- have an average thermal conductivity of about 0.45 W/mK. As a main conclusion, the ter blocks have an average thermal conductivity of about 0.45 W/mK. As a main con- developed gypsum plaster blocks have a low thermal conductivity value, 0.35 W/mK ≤ λ clusion, the developed gypsum plaster blocks have a low thermal conductivity value, ≤ 0.87 W/mK [31], for use as an insulation building material for the construction of inte- 0.35 W/mK    0.87 W/mK [31], for use as an insulation building material for the con- rior walls. struction of interior walls. Figure 17. Thermal conductivity measurement using boxes method test [27]. Figure 17. Thermal conductivity measurement using boxes method test [27]. 5.4. Discussion 5.4. Discussion Experimental tests results on gypsum plaster block prototypes show that these blocks Experimental tests results on gypsum plaster block prototypes show that these can be an alternative for insulation building materials for interior walls construction. This blocks can be an alternative for insulation building materials for interior walls construc- result makes the possibility to manufacture this new block due to these reasons: tion. This result makes the possibility to manufacture this new block due to these reasons: - They have a tolerated dimensions after drying. ­ They have a tolerated dimensions after drying. - They have a flat surface. ­ They have a flat surface. - They are considered lightweight blocks because of their very low density, about ­ They are considered lightweight blocks because of their very low density, about 865 865 kg/m . kg/m . - They have a recommended compressive strength for wall construction. ­ They have a recommended compressive strength for wall construction. - They can be used only after one day because of their very quick setting. ­ They can be used only after one day because of their very quick setting. Finally, a prototype of an interior wall was constructed using the new gypsum plaster blocks and a mortar of gypsum plaster and water, as shown in Figure 18. Buildings 2022, 12, 1297 15 of 17 Buildings 2022, 12, x FOR PEER REVIEW 16 of 18 Finally, a prototype of an interior wall was constructed using the new gypsum plaster blocks and a mortar of gypsum plaster and water, as shown in Figure 18. Figure Figure 18. 18. Steps Steps of of wall wall protot prototype ype constructio construction. n. The following conclusions were noted: The following conclusions were noted: The construction of the walls by the new blocks is very easy and very fast due to the • The construction of the walls by the new blocks is very easy and very fast due to the flat surfaces and to the similarity in size of blocks. flat surfaces and to the similarity in size of blocks. Compared with the ordinary brick blocks, the mortar consumption is considerably low. • Compared with the ordinary brick blocks, the mortar consumption is considerably The possibility of faience attachment was observed. low. There are no cracks observed at joints between blocks. • The possibility of faience attachment was observed. • There are no cracks observed at joints between blocks. 6. Conclusions This work presents the results of an experimental study on a new design of green 6. Conclusions gypsum plaster blocks with circular alveolar. This work presents the results of an experimental study on a new design of green The main conclusions of the experimental results are the following: gypsum plaster blocks with circular alveolar. - Gypsum plaster blocks have a tolerated dimensions after drying. The main conclusions of the experimental results are the following: - The flatness index shows that gypsum plaster blocks have a flat surface. ­ Gypsum plaster blocks have a tolerated dimensions after drying. - Gypsum plaster blocks can be considered as average density blocks because of their ­ The flatness index shows that gypsum plaster blocks have a flat surface. very low density. ­ Gypsum plaster blocks can be considered as average density blocks because of their - Gypsum plaster blocks have a recommended compressive strength for wall construction. very low density. - Gypsum plaster blocks have very quick setting. ­ Gypsum plaster blocks have a recommended compressive strength for wall con- - The construction of the walls by the new blocks is very easy and very fast due to the struction. flat surfaces and to the similarity in size of blocks. ­ Gypsum plaster blocks have very quick setting. - Because these gypsum blocks are very sensitive to water, they are not intended for ­ The construction of the walls by the new blocks is very easy and very fast due to the dry zones. flat surfaces and to the similarity in size of blocks. ­ Because these gypsum blocks are very sensitive to water, they are not intended for Author Contributions: Funding acquisition, H.Y.B.K. and W.J.K.; investigation, O.B.; supervision, dry zones. O.B.; visualization, N.M.; writing—original draft, O.B.; writing—review and editing, H.Y.B.K., W.J.K., O.B., and N.M. All authors have read and agreed to the published version of the manuscript. Author Contributions: Funding acquisition, H.Y.B.K. and W.J.K.; investigation, O.B.; supervision, Funding: This research was funded by [CENTRE OF EXCELLENCE] grant number [J510050002-IC- O.B.; visualization, N.M.; writing—original draft, O.B.; writing—review and editing, H.Y.B.K., 6BOLDREFRESH2025] and the APC was funded by [CENTRE OF EXCELLENCE]. W.J.K., O.B., and N.M. All authors have read and agreed to the published version of the manu- script. Institutional Review Board Statement: Not applicable. Funding: This research was funded by [CENTRE OF EXCELLENCE] grant number [J510050002-IC-6BOLDREFRESH2025] and the APC was funded by [CENTRE OF EXCELLENCE]. Institutional Review Board Statement: Not applicable. Buildings 2022, 12, 1297 16 of 17 Informed Consent Statement: Not applicable. Data Availability Statement: Not applicable. Acknowledgment: Acknowledgment to grant no.: J510050002-IC-6 BOLDREFRESH2025-CENTRE OF EXCELLENCE. Conflicts of Interest: The authors declare no conflict of interest. Collaborators: University Tenaga Nasional, Malaysia; Prince Sattam bin Abdulaziz University, Saudi Arabia; Curtin University, Australia. References 1. Morgan, D.J. Thermal analysis including evolved gas analysis of clay raw materials. Appl. Clay Sci. 1993, 8, 81–89. [CrossRef] 2. Santos, D.R.; Toledo, R.; Faria, R.T., Jr.; Carrio, J.G.; Da Silva, M.G.; Auler, L.T. Evolved gas analysis of clay materials. Rev. Sci. Instrum. 2003, 74, 663–666. [CrossRef] 3. Toledo, R.; dos Santos, D.R.; Faria, R.T., Jr.; Carrio, J.G.; Auler, L.T.; Vargas, H. Gas release during clay firing and evolution of ceramic properties. Appl. Clay Sci. 2004, 27, 151–157. [CrossRef] 4. Gonzalez, I.; Galan, E.; Miras, A.; Vazquez, M.A. CO emissions derived from raw materials used in brick factories. Applications to Andalusia (Southern Spain). Appl. Clay Sci. 2011, 52, 193–198. [CrossRef] 5. Cusido, J.A.; Cremades, L.V.; Gonzalez, M. Gaseous emissions from ceramics manufactured with urban sewage sludge during firing processes. Waste Manage. 2003, 23, 273–280. [CrossRef] 6. Mansour, B.M.; Soukaina, A.C.; Benhamou, B.; Jabrallah, B.S. Thermal characterization of a Tunisian gypsum plaster as Construc- tion Material. Energy Proc. 2013, 42, 680–688. [CrossRef] 7. Xamán, J.; Lira, L.; Arce, J. Analysis of the temperature distribution in a guarded hot plate apparatus for measuring thermal conductivity. Appl. Therm. Eng. 2009, 29, 617–623. [CrossRef] 8. Salmon, D. Thermal conductivity of insulations using guarded hot plates, including recent developments and source of reference materials. Meas. Sci. Technol. 2001, 12, 89–98. [CrossRef] 9. Fabio, S.M.; Renata, N.T. Infrared thermography applied to the quantitative determination of spatial and thermophysical parameters of hidden included objects. Appl. Therm. Eng. 2007, 27, 2378–2384. 10. Jannot, Y.; Zoubir, A. A quadrupolar complete model of the hot disc. Meas. Sci. Technol. 2007, 18, 1229–1234. [CrossRef] 11. Jannot, Y.; Meukam, P. Simplified estimation method for the determination of thermal effusivity and thermal conductivity with a low cost hot strip. Meas. Sci. Technol. 2004, 15, 1932–1938. [CrossRef] 12. Coquard, D.; Baillis, D.; Quenard, D. Experimental and theoretical study of the hot-wire method applied to low-density thermal insulators. Int. J. Heat Mass Transf. 2006, 49, 4511–4524. [CrossRef] 13. Koksal, F.; Gencel, O.; Kaya, M. Combined effect of silica fume and expanded vermiculite on properties of lightweight mortars at ambient and elevated temperatures. Constr. Build. Mater. 2015, 88, 175–187. [CrossRef] 14. Korjenic, A.; Zach, J.; Hroudová, J.; Petránek, V.; Korjenic, S.; Bednar, T. Development and optimization of advanced silicate plasters materials for building rehabilitation. In Proceedings of the 2nd Central European Symposium on Building Physics, Vienna, Austria, 9–11 September 2013; pp. 863–867. 15. Václavík, V.; Daxner, J.; Valícek, ˇ J.; Dvorský, T.; Kušnerová, M.; Harnic ˇárová, M.; Bendová, M.; Brenek, ˇ A. The use of industrial waste as a secondary raw material in restoration plaster with thermal insulating effect. Adv. Mat. Res. 2014, 897, 204–214. [CrossRef] 16. Vieira, J.; Senff, L.; Goncalves, H.; Silva, L.; Ferreira, V.M.; Labrincha, J.A. Functionalization of mortars for controlling the indoor ambient of buildings. Energ. Build. 2014, 70, 224–236. [CrossRef] 17. Hroudová, J.; Zach, J.; Hela, R.; Korjenic, A. Advanced, Thermal Insulation Materials Suitable for Insulation and Repair of Buildings. Adv. Mat. Res. 2013, 688, 54–59. [CrossRef] 18. Zach, J.; Korjenic, A.; Hroudová, J. Study of behaviour of advanced silicate materials for heating and moisture rehabilitation of buildings. Adv. Mat. Res. 2013, 649, 167–170. 19. Gencel, O.; Diaz, J.J.C.; Sutcu, M.; Koksal, F.; Rabanal, F.P.A.; Barrera, G.M.; Brostow, W. Properties of gypsum composites containing vermiculite and polypropylene fibers: Numerical and experimental result. Constr. Build. Mater. 2014, 70, 135–144. [CrossRef] 20. Khalil, A.A.; Tawfik, A.; Hegazy, A.A.; El-Shahal, M.F. Effect of some waste additives on the physical and mechanical properties of gypsum plaster composites. Constr. Build. Mater. 2014, 68, 580–586. [CrossRef] 21. Benazzouk, A.; Douzane, O.; Mezreb, K.; Laidoudi, B.; Queneudec, M. Thermal conductivity of cement composites containing rubber waste particles, experimental study and modelling. Constr. Build. Mater. 2008, 22, 573–579. [CrossRef] 22. NF P94-057; Soils Investingation and Testing. Granulometric Analysis. Hydrometer Method. May 1992. Available on- line: https://www.boutique.afnor.org/en-gb/standard/nf-p94057/soils-investingation-and-testing-granulometric-analysis- hydrometer-method/fa020768/11074#AreasStoreProductsSummaryView (accessed on 19 May 2022). 23. ASTM Standard D2487; Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). ASTM International: West Conshohocken, PA, USA, 2000. Buildings 2022, 12, 1297 17 of 17 24. NF EN 196; Methods of Testing Cements—Part 6: Determination of Fineness. 6 April 2012. Available online: https://www. boutique.afnor.org/en-gb/standard/nf-en-1966/methods-of-testing-cement-determination-of-fineness/fa187053/83194 (ac- cessed on 19 May 2022). 25. NF EN 1097-7; Tests for Mechanical and Physical Properties of Aggregates—Part 7: Determination of the Particle Density of Filler-Pyknometer Method. June 2008. Available online: https://www.boutique.afnor.org/en-gb/standard/nf-en-10977/tests- for-mechanical-and-physical-properties-of-aggregates-part-7-determina/fa155696/31162 (accessed on 19 May 2022). 26. NF EN 12390; Testing Hardened Concrete-Part4: Compression Strength-Specification for Testing Machines, European Committee for Standardization CEN: Brussels, Belgium, 2009. Available online: https://www.boutique.afnor.org/en-gb/results?Keywords= NF+EN+12390&StandardStateIds=1 (accessed on 19 May 2022). 27. Alyousef, R.; Benjeddou, O.; Soussi, C.; Khadimallah, M.A.; Jedidi, M. Experimental Study of New Insulation Lightweight Concrete Block Floor Based on Perlite Aggregate. Adv. Mater. Sci. Eng. 2019, 2019, 8160461. [CrossRef] 28. Ben Mansour, M.; Cherif, A.S.; Ben Jabrallah, S.; Benhamou, B. Caractérisation thermique d’un plâtre de gypse tunisien utilisé en tant que matériau de construction. In Proceedings of the EcoMAT2013, Ougadougou, Burkina Faso, 10–12 June 2013. 29. NF EN 12859; Gypsum Blocks-Definitions, Requirements and Test Methods. April 2011. Available online: https://www.boutique. afnor.org/en-gb/results?Keywords=NF+EN+12859&StandardStateIds=1 (accessed on 19 May 2022). 30. NF EN 772-21; Methods of Test for Masonry Units—Part 21: Determination of Water Absorption of Clay and Calcium Silicate Masonry Units by Cold Water Absorption. August 2011. Available online: https://www.boutique.afnor.org/en-gb/results? Keywords=NF+EN+772-21&StandardStateIds=1 (accessed on 19 May 2022). 31. NF EN ISO 8990; Thermal Insulation-Determination of Steady-State Thermal Transmission Properties-Calibrated and Guarded Hot Box. 1996. Available online: https://www.boutique.afnor.org/en-gb/results?Keywords=NF+EN+ISO+8990&StandardStateIds=1 (accessed on 19 May 2022).

Journal

Buildings – Multidisciplinary Digital Publishing Institute

Published: Aug 24, 2022

Keywords: experimental investigation; energy; insulation; green; gypsum plaster; mixture; block

There are no references for this article.