Firing Temperature Research Articles

Microstructure and strength of microporous MgO refractory aggregates with nano-sized pores

ABSTRACT In this work, microporous MgO refractory aggregates with nano-sized pores were prepared by in situ decomposition method using Mg(OH)2 as raw material. The effects of firing temperatures (1600–1700°C) and compacting pressures (100–200 MPa) on the microstructures and properties of microporous MgO refractory aggregates were thoroughly studied. The results showed that the microporous MgO refractory aggregates contained two types of pore structures, which were intra-particle pores with pore sizes of 180.0–230.0 nm formed by in situ decomposition of Mg(OH)2 and inter-particle pores with pore sizes of 1.5–3.0 μm derived from particle packing between Mg(OH)2 pseudomorph particles, respectively. Besides, the firing temperatures had a great influence on the intra-particle pore size and microcrystallite size. And the compacting pressures not only influenced the intra-particle pore size via packing behaviors but also affected the inner firing behaviors of the pseudomorph particles due to the increase in H2O vapor pressure. Overall, at a compacting pressure of 150 MPa and firing temperature of 1650°C, the sample had the best comprehensive performance with a bulk density of 1.92 g/cm3, a compressive strength of 11.9 MPa, an apparent porosity of 45.0%, a relative aggregate tube strength of 25.2% and a median pore size of 262.3 nm.

A Probabilistic Model for Fire Temperature Rise in High-Rise Residential Buildings under the Action of Uncertain Factors

Due to the randomness of interior combustibles, wall thermal inertia, and opening factor, the fire temperature rise in high-rise residential buildings is uncertain. This study investigated 38 urban high-rise residential buildings, created the probability density functions of fire load density, opening factor, and wall thermal inertia, and constructed random fire scenarios for urban high-rise residential buildings. On this basis, relying on the Latin Hypercube Sampling method, this study further explored the probabilistic model for fire temperature rise in urban high-rise residential buildings under the action of uncertain factors, generated the possible temperature rise curves of fires in urban high-rise residential buildings and their probability distribution, and established the most representative temperature rise curve.

SYNTHESIS OF WOLLASTONITE-CONTAINING CERAMICS FROM NATURAL RAW MATERIALS OF THE REPUBLIC OF BELARUS

Compositions of ceramic masses for obtaining wollastonite-containing ceramics using domestic carbonate and siliceous raw materials were developed. The features of the formation of the structure and phase composition of synthesized ceramic materials in connection with the physicochemical properties and operational characteristics were established. The influence of a mineralizing additive (naturally occurring wollastonite) on the processes of sintering and phase formation was determined, the relationship between the physical-technical and thermophysical properties, the firing temperature and the amount of additive introduced was revealed. The results of the research are of theoretical and practical interest in organizing the production of refractory products based on wollastonite.

INVESTIGATION OF DISPERSED PARTICLE-HARDENED ZIRCONIUM PORCELAIN

Porcelains were prepared by using kaolin clay, potassium feldspar, and quartz as the raw materials, and ZrO2 as a reinforcing material. This study investigated the effects of the amount of ZrO2, the firing temperature, and the holding time on the porcelain bending strengths and fracture toughness values, and compared the reinforcing effects of two types of ZrO2. The results show that the effect of the two types of ZrO2 (pure ZrO2 and Y2O3-stabilized ZrO2) on porcelain reinforcement were similar and that the optimal porcelain reinforcement was obtained with a ZrO2 content of 6 wt.%, firing temperature of 1300 ?, and holding time of 30 min. The bending strength increased from (58 ± 6) MPa to (89 ± 8) MPa (pure ZrO2) and (87 ± 8) MPa (Y2O3- stabilized ZrO2), with the respective growth rates reaching 62 and 58 %. Radial stress was generated in the matrix during the cooling process because of the difference between the thermal expansion coefficients of ZrO2 particles and the matrix. This increased the porcelain strength. The phase transformation of ZrO2 improved the fracture toughness of the porcelain, but had little effect on reinforcement of the porcelain.

Ceramics Properties of Indurated-Shale Quarry Wastes from Abakaliki, Southeastern Nigeria: Application as Raw Materials in Roofing-Tile Production

AbstractThe present study describes research carried out to evaluate the mineralogical, geochemical and technological properties of indurated shale-quarry wastes and assess the suitability of these low-cost and locally available quarry wastes generated from crushed indurated shales for possible use as alternatives to fresh raw materials in the manufacture of roofing-tile products. Firstly, the mineralogical and chemical properties of the indurated shales were investigated by X-ray diffraction (XRD) and X-ray fluorescence, while their physical properties were identified by grain-size distribution, Atterberg limits, and clay activity. Samples of indurated shale-quarry wastes (ISQWs) were subjected to heat treatment at elevated firing temperatures to provide the required strength and durability and their ceramics properties (linear shrinkage, weight loss, water absorption, bulk density, and flexural strength) were determined. From the results, the ISQWs were composed predominantly of fine particles with medium plasticity and clay activity with values generally >0.75. The mineralogy revealed a predominance of aluminosilicates (illite-kaolinite-smectite-chlorite) with large quartz contents and variable percentages of carbonate and feldspar. The oxides were dominated by SiO2 and Al2O3, small amounts of ferromagnesian minerals, and considerable amounts of alkalis (K2O and Na2O) which act as fluxes. The CaO concentrations were variable and related to carbonate contents. Characterizations based on compositional ternary (total clay mineral-carbonate-quartz + feldspar) systems, Casagrande clay workability charts, and Winkler and McNally diagrams revealed their suitability for ceramics applications as the majority of ISQW samples fell within the specifications for roofing tiles. The ISQWs fired at a high temperature of 1000°C revealed considerable weight loss, reduction in both linear shrinkage and water absorption with insignificant increase in flexural strength. In order to achieve excellent ceramics properties and further reduce sintering temperature for their suitability as raw materials in the production of roofing tiles, beneficiations of ISQWs are highly recommended.

The investigation of the physical properties of an electrical porcelain insulator manufactured from locally sourced materials

Abstract The work aims to evaluate the effect of temperature and composition on the physical properties of ceramic electrical porcelain insulators, produced from locally sourced materials in Nigeria. The basic raw materials of triaxial porcelain (Kaolin, feldspar, and quartz) were pulverized, milled for 22 h, and sieved using a 200 μm mesh size. The chemical composition and characterization of the raw materials were obtained using X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis. The mixtures were formulated using sodium silicate as a deflocculant to help produce the ceramic porcelain samples. The green samples were weighed and fired at temperatures of 1200 °C and 1250 °C. The samples were subjected to 1 h of boiling plus 2 h of soaking. The slip casting technique was used in the production of porcelain insulators. The linear shrinkage, water absorbance, apparent porosity, and bulk density were measured and studied as a function of firing temperature. The apparent porosity and water absorption decreased as the firing temperature increased. The bulk density increased gradually from 1200 °C to 1250 °C and the percentage of moisture remained fairly unaffected by the temperature increase. The linear shrinkage was also found to increase as the firing temperature increased. Despite having the same composition, the average physical properties of the locally manufactured insulators revealed that those manufactured at higher temperatures provided a better insulating effect than those manufactured at lower temperatures. In other words, it shows that excellent ceramic porcelain insulators can be manufactured from locally sourced materials using the appropriate composition and firing temperature.

The Effect of the Dispersion Nickel Slag Additive on the Strength of Ceramic Bricks

The influence of the dispersion of the nickel slag additive on the strength of ceramic bricks based on low-melting clay of the Khalilovsky deposit in the Orenburg region and nickel slag from the dumps of OJSC "Combine Yuzhuralnickel" (Orenburg region) is considered. The study involves assessing the effect of the preparation method, the dispersion of the additive (nickel slag) on the microstructure of the finished samples. Using modern research methods with the involvement of high-tech equipment, the micro-and macrostructure of ceramic samples with the addition of slag in an amount of 5–60% is considered. The structure of the synthesized samples is studied by the method of mercury porosimetry depending on the percentage ratio of clay / slag and the fineness of grinding of the nickel slag additive. The data on the influence of the material composition of the clay / slag charge, the dispersity of the additive and the firing temperature on the strength of the prototypes are given, and an assessment is made of the technological feasibility of increasing the dispersion of the raw materials used. Intorduction

Real-time monitoring and prediction method of commercial building fire temperature field based on distributed optical fiber sensor temperature measurement system

In order to accomplish the task of real-time monitoring and prediction of fire temperature in commercial buildings, this study proposes a sensor arrangement method based on sensor and fire field characteristics to better reflect the fire temperature changes of building space, and conducts high temperature sensor measurement experiments based on this method. Then the study carries out fire dynamics simulations to establish a temperature change dataset containing fire and sensor temperature changes. The study establishes several prediction models using different algorithms based on the dataset, and the models built by artificial neutral network (ANN) and long short-term memory (LSTM) respectively have the best performance. The results show that the percentage error between the output temperature of the ANN mapping model and the actual temperature of the fire key plane is 1.94%. The percentage error between the output temperature of the LSTM temperature prediction model and the actual temperature is 1.03%, which satisfies the demand for early warning of the fire temperature hazard. This study also validates the generalization of the two models for fire temperature prediction in different spatial areas, and the method can provide a good solution for real-time monitoring and early warning of fire temperature in commercial buildings.

CHEMICAL AND MINERALOGICAL ANALYSES OF THE LATE NEOLITHIC CERAMICS FROM ŞAH VALLEY (SINGUBER), TURKEY

Numerous settlements have been identified during the surveys in Şırnak province (Turkey) since the beginning of the 19th century. The potsherds found in the central of such settlements have been thought to be affected by Mesopotamian culture, and the ones from the hillside of the Şah Valley were considered as the most eastern examples of the Hassuna Samara culture. This study presents the results regarding one of the first detailed archaeometric investigations carried out for the Late Neolithic ceramic findings unearthed from Şah Valley (Şırnak province, Turkey). The ceramics were initially characterized by means of portable X-ray florescence (p-XRF) and X-ray diffraction (XRD) in order to enlighten the chemical and mineralogical features of the samples, respectively. The results indicated use of calcareous raw material sources and a low firing temperature range (ca. 700-800oC). The potsherds were also investigated through petrography which showed the presence of quartz, opaque minerals, plagioclase and biotite as the minerals, and clay, claystone and marl rock contents as the rock types for the samples, in general. Fourier transformed infrared (FTIR) spectroscopy was additionally applied for the potsherds. This complementary technique provided information about the vibrations of the chemical bands in the ceramics which displayed the characteristic bond vibrations of decisive minerals in the ceramic fabrics, such as calcite, clay minerals and quartz. Considering the whole archaeometric data, it can be deduced that the Neolithic ceramics of the Şah Valley have been subjected to low firing temperatures which could be assigned to a basic production procedure presumably claiming daily-use wares.

Study of physical and mechanical behavior of artificial lightweight aggregate made of Pakistani clays

This study aims to unravel the potential of Pakistan in the domain of artificial lightweight expanded clay aggregates (ALECA) and investigate the influence of pellets size, firing temperature, and admixture doses on the mechanical properties of ALECA. The five prominent and unfathomed clay fields in Pakistan were chosen. The selected clay fields include Nandipur, Multan, Mirpur, Sibbi, and DIK. After essential geotechnical characterization, the collected soil samples of chosen fields were chemically analyzed using X-ray diffraction and X-ray fluorescence tests, whereas thermal stability was assessed using thermogravimetric analysis. The characterized soil was used in the synthesis of ALECA through 120 different mixes recipes designed by varying pellet sizes, and the dose of admixed fly ash and kerosene oil. The addition of fly ash and kerosene allowed the development of a well-distributed-porous core surrounded by a very thin shell. Nandipur clay turned out to be ideal for bloating, with a bloating index of 33.33 % and a loose bulk density of 0.39 g/cm3. These lightweight aggregates will not only help preserve natural mountain reserves but also significantly impact the lifecycle costing of structures.

Experimental Study on the Smoke Temperature Decrease near Natural Vents Induced by Air Entrainment in a Tunnel Fire

Previous studies have shown that there is a large difference in the temperature of smoke in the upstream and downstream of a vertical shaft, but no quantitative study on the subject has been conducted. In this paper, a model experimental test was conducted to study the effect of a natural vertical shaft on the distribution of smoke temperature in tunnel fires. A laser sheet was used as an assisting tool to show the smoke flow field. A series of tests were conducted with shaft heights varying from 0.2 m to 1.2 m and a heat release rate (HRR) of 9 kW, 17 kW, 29 kW, and 65 kW. The entrainment phenomenon around the vertical shaft was analyzed, and the results showed that the amount of fresh air entrainment is the main reason for the temperature decrease in upstream and downstream smoke temperatures. Based on the experimental results, an empirical model for predicting the amount of fresh air entrainment and a prediction model of the downstream smoke temperature were proposed, and the predicted values are in good agreement with the experimental values.

Synthesis of zircon pigments from rice husk ash and their performance in ceramic glaze

ZrSiO4-based pigments have been known to be very stable in ceramic glazes but require a high firing temperature required for phase formation. This study examined the feasibility of using rice husk waste as a substitute for crystalline SiO2. The amorphous form of silica with some impurities was obtained by calcining the rice husk at 800℃. The general chemical formula were (Zr0.9M0.1)SiO4, where M = V, Pr, Fe and Cr. The solid-state processing was achieved by firing at 1300℃ for 12 h with NaF (5 wt%). X-ray Diffraction revealed a lower relative fraction between ZrO2 (secondary phase) and ZrSiO4 in the RHA systems compared to the oxide system for all dopants. Amorphousness of RHA did help enhance phase formability. The particle sizes were in the 3 µm to 5 µm range. Elemental analysis revealed some areas with intense signals of zirconium, indicating unreacted ZrO2 particles. Colorations appeared to be blue, yellow, brown and green for dopants of V, Pr, Fe and Cr, respectively. Technological performance was tested in a practical ceramic glaze and frequently used raw materials fired at its maturation point. The results of this study hold huge potential for using rice husks for sustainable manufacturing of pigments as green products.

Utilization of marble waste as a sustainable replacement for calcareous in the manufacture of red-firing wall tiles

Marble waste generated in large amounts in the ornamental rock industry needs to be disposed of in a sustainable way and valorized. In this respect, this work analyzed the use of marble waste as a sustainable raw material in manufacturing red-firing wall tiles, replacing the natural calcareous material by up to 15 wt%. For this purpose, four red-firing wall tile pastes containing marble waste were pressed into rectangular pieces and fired between 1100 °C and 1180 °C using a fast-firing cycle. The red-firing wall tile specimens produced were tested to determine their technical properties (linear shrinkage, water absorption, apparent density, and three-point flexural strength), phase analysis by XRD, and microstructural analysis by SEM. The densification behavior and technical properties of these specimens were influenced by the incorporation of marble waste and firing temperature. The results showed that this waste is highly compatible for the manufacture of high-quality red-firing wall tiles, meeting the normative requirements (water absorption and flexural strength) of group-BIII of ISO 13006. The marble waste may fully replace the natural calcareous used in the manufacture of this type of tile material, contributing to its recycling and valorization with positive repercussions for both the ornamental rock and ceramic industries.

Effect of High Temperature on Mechanical Properties and Microstructure of HSFCM

A new type of composite cement-based cementing material—high-strength fast cementing material (HSFCM)—will be widely used in marine engineering projects such as submarine tunnels. However, the influence of fire and other high temperature conditions on its material properties have not been explored in previous studies. Mechanical tests and microstructure observations of HSFCM were carried out, and the strength and deformation characteristics, microstructure and composition evolution of HSFCM after high temperature treatment were discussed. After high temperature treatment, the compressive strength of HSFCM deteriorated. The compressive strength of HSFCM decreased by more than half at 400 °C. The peak strain increased at 200 °C with the increase of temperature, and decreased at 400~600 °C with the increase of temperature. High temperature reduces the stiffness of HSFCM, and the elastic modulus decreases with increasing temperature. The influence of high temperature on the microstructure of HSFCM is mainly shown in the increase and enlargement of pores in three-dimensional space, the development of micro-cracks and the thermal decomposition of cementing material into stable oxides without cementing effect. The microscopic changes of HSFCM are in good agreement with the mechanical test results.

Post-Fire Mechanical Properties of Concrete Incorporating Waste EPS (Styrofoam) as Aggregate Replacement

Reusing waste is one of the most recent topics and one of the main contributors to sustainability. It is known that concrete is one of the most common materials to produce different types of construction members around the world. That is due to mainly its low cost, availability, long period of durability, and ability to withstand harsh environments. On the other hand, due to the rapid changes that have happened in the last few decades in the production of decorative materials, some material types of cladding are used for decoration purposes, such as Styrofoam (EPS) (trade name “Astropol”), which is developed from disposal materials. Discovering and implementing a method of reusing these wastes in concrete is beneficial for the environment to reduce waste around the globe. In the current study, Styrofoam (Astropol) waste was used as a replacement for fine aggregate since concrete structures contain this material in their composition. It is important to test these materials for fire resistance and expose them to an elevated temperature in order to discover the post-fire mechanical properties of the composite material. The experimental result showed that the post-fire compressive strength of concrete containing different ratios of EPS (Astropol) increases compared to conventional concrete. The compressive strengths were 19.94 MPa, 19.295 MPa, 16.806 MPa, and 17.66 MPa for 0%, 15%, 25%, and 50%, respectively, while the post-fire indirect tensile strength for all specimens containing EPS reduced as the fire duration and temperature increased.

Ancient Conflagration: a Reconstruction of a Middle Formative Fire at the Chiripa Mound, Bolivia

In this study, we assess competing interpretations of a burnt ceremonial structure from the terminal Middle Formative period (ca. 300–100 BCE) by analyzing the stepped platform mound at Chiripa, Bolivia, through a systematic reconstruction of the fire that destroyed it. We developed a model of potential fire pathways, their social contexts, and material indicators. Our approach contrasts incipient fires from accident or arson to planned fires initiated for functional or social ends. We assessed these pathways for the Chiripa mound fire through experimental, geoarchaeological, faunal, and botanical data. Experiments were aimed at deducing the temperature, duration, and oxidation conditions of the fire. The fire temperature and duration were approximated from geoarchaeological analyses of construction materials in comparison with controls, and thermal alteration of faunal bone. Fuels were reconstructed through paleoethnobotanical analysis of charred remains from discrete areas within the burnt structure. We conclude that an intentional fire burned the structures on the Chiripa mound to temperatures of 700 °C or higher under oxidizing conditions for several hours. The pattern of heat-altered materials recovered would have required a substantial supplemental fuel load. At the 3840 masl elevation of Chiripa, the effective control of a high temperature oxidizing fire demonstrates technical expertise in fire management. Our findings indicate the fire appears intentional, likely a ritual event. We believe the structures were burned to facilitate a socio-political change during a period of social transition at the end of the Middle Formative period in Bolivia.

Influence of Short Carbon Fibers on the Properties of Autoclaved Fiber Cement in Standard Fire Environment.

In case of a fire, the flame can spread from the building through the outer openings to the outside. In such cases, the fire temperature thermal effect determines the façade fibrocement tile thermal destruction, while the flammable thermo-insulating systems used for building energy effectiveness ensures it sets on fire. The spread of such a fire becomes uncontrollable and raises an immediate danger to the people inside the building, while such event dynamics delay and make it harder to put out the fire. Extra additive usage in façade fibrocement tiles can raise its resistance to fire temperature effect. Carbon fiber is widely known as a material resistant to the high temperature destructive effect. An investigation was conducted on the influence that carbon fiber has on the properties of autoclaved fiber cement samples. The autoclaved fiber cement samples were made from the raw materials, typical for façade fiber cement plates, produced in an industrial way (using the same proportions). In the samples, carbon fiber was used instead of mix cellulose fiber in 0.5%, 0.75%, 1% proportions. After completing the density research, it was determined that the carbon fiber effect had no general effect on the sample density. Ultrasound speed spreading research showed that the carbon fiber insignificantly makes sample structure denser; however, after the fire temperature effect, sample structure is less dense when using carbon fiber. The results of both these investigations could be within the margin of error. Insignificant sample structure density rise was confirmed with water absorption research, which during the 1% carbon fiber usage case was lower by 4.3%. It was found that up to 1% carbon fiber usage instead of mix cellulose fiber creates a dense structure of autoclaved fiber cement samples, and the carbon fiber in the microstructure influences the mechanical properties of the autoclaved fiber cement samples. After using carbon fiber in ambient temperature, the sample compressive strength and bending strength increased. However, the results of mechanical properties were completely different after experiencing fire temperature effect. Scanning electron microscopy research showed that the bond between the carbon fiber and the cement matrix was not resistant to high temperature effect, due to which the structure of the samples with carbon fiber weakened. Research showed that carbon fiber lowers the mechanical properties of the autoclaved fiber cement samples after high temperature effect. After analyzing the density, ultrasound speed spreading, water absorption, microstructure and macrostructure, compressive strength, and bending strength, the authors determined the main CF usage for AFK dependencies: 1. CF usage up to 1% replacing MCF makes the AFK structure more dense up to 1.5%, and lowers the water absorption up to 4.3%; 2. CF incorporates itself densely into the AFC microstructure; 3. CF usage up to replacing MCF improves the AFK strength properties up to until the fire temperature effect. Compression strength increases up 7.3% while bending strength increases up to 14.9%. 4. AFK hydrate amount on CF surface is lower than on MCF; 5. Fire temperature effect on AFK with CF causes dehydration by removing water vapor from the microstructure, resulting in a lot of microcracks due to stress; 6. The CF and cement matrix contact zone is not resistant to fire temperature effect. SEM experiments were used to determine the CF "self-removing" effect; 7. Due to complex changes happening in the AFK during fire temperature effect, CF usage does not improve strength properties in the microstructure. Compression strength decreases to 66.7% while bending strength decreases to 20% when compared with E samples.

Using simulated wildland fire to assess microbial survival at multiple depths from biocrust and bare soils.

Surface soil microbial communities are directly exposed to the heat from wildland fires. Due to this, the microbial community composition may be stratified within the soil profile with more heat tolerant microbes near the surface and less heat tolerant microbes, or mobile species found deeper in the soil. Biological soil crusts, biocrusts, are found on the soil surface and contain a diverse microbial community that is directly exposed to the heat from wildland fires. Here, we used a simulated fire mesocosm along with a culture-based approach and molecular characterization of microbial isolates to understand the stratification of biocrust and bare soil microbes after low severity (450°C) and high severity (600°C) fires. We cultured and sequenced microbial isolates from 2 to 6 cm depth from both fire types. The isolates were stratified along the soil depth. Green algal isolates were less thermotolerant and found in the deeper depths (4-6 cm) and the control soils, while several cyanobacteria in Oscillatoriales, Synechococcales, and Nostocales were found at 2-3 cm depth for both fire temperatures. An Alphaproteobacteria isolate was common across several depths, both fire types, and both fire temperatures. Furthermore, we used RNA sequencing at three depths after the high severity fire and one control to determine what microbial community is active following a fire. The community was dominated by Gammaproteobacteria, however some Cyanobacteria ASVs were also present. Here we show evidence of stratification of soil and biocrust microbes after a fire and provide evidence that these microbes are able to survive the heat from the fire by living just below the soil surface. This is a steppingstone for future work on the mechanisms of microbial survival after fire and the role of soil insulation in creating resilient communities.

Experimental analysis on thermophysical properties of clay found in geographical areas of India and their ability to cool water for semi-arid climate regions

The Thermo physical behaviour of soil is the fundamental behaviour and plays significant position in its “utilization” as “electrical and heat insulation”. However, numerous “researchers have studied” thermo-physical properties of soil. Still, the study on the relationship between soil's properties and its cooling effect through evaporation has not been investigated in detail. In this analysis, soil samples and earthen pots were collected from four states of India: Haryana, Delhi, Rajasthan, and Uttar Pradesh. The performance parameters used to evaluate the cooling effect of the soil, and earthen pot samples are “water-holding capacity”, porosity, “thermal-conductivity”, texture, and particle and bulk density. The application of “high temperature” fluctuate the “internal microstructure” of clay/soil and subsequently disturbs its “physical and thermal properties”. The sand/clay is converted into an earthen pot by applying high temperatures in kilns. The pot samples collected are heated in kilns to bring them to the final form for the study. We are studying the properties after that treatment. In this paper, the impact of “firing temperature” (maximum 900°C) on the “thermo-physical properties” of earthen pots made up of soil of a similar kind as the soil samples collected and the impact of thermo-physical properties on the cooling of the earthen pots has been examined via experiments. The results specify that the “thermal conductivity” of soil/clay samples is less compared to earthen pot. The “porosity and water-holding capacity” of the soil are greater than earthen pots because pore space or pore volume has decreased due to the heating effect. From the experimental analysis, it was found that the soil of the Sohna location in Haryana state has a high water cooling capacity due to its high water-holding (49.28%) capacity and porosity (48.75%). The pot made out of clay, having higher porosity, and water-holding capacity, gives the maximum cooling temperature.

Physical-mechanical properties and thermogravimetric analysis of fired clay brick incorporating palm kernel shell for alternative raw materials

This article explores the potential of incorporating palm kernel shells (PKS) from palm oil mill waste as a clay replacement for fired clay bricks. PKS, an abundant byproduct of palm oil extraction, have high cellulose content and high calorific value, making them an ideal option for clay replacement in brick making. For this purpose, clay soil was replaced with different percentages of PKS (0, 1, 5 and 10%) and subjected to a firing temperature of 1050 °C (heating rate of 1 °C/min). The physical–mechanical properties such as shape, size, colour, dry density, water absorption, thermal conductivity, porosity and compressive strength, as well as microstructural and morphological properties (XRD, SEM-EDX and digital image) and thermal analysis data (TGA-DTA) were evaluated to determine the effects of replacing PKS in fired clay bricks. The results showed that the incorporation of PKS increased firing shrinkage and porosity and decreased dry density, compressive strength, and thermal conductivity. However, incorporating more than 5% PKS resulted in lower mechanical properties (24.6 to 11.0 MPa) and higher water absorption (3 to 12%) due to increased firing shrinkage and porosity (0.3 to 0.9% and 13 to 20%, respectively). The bricks also exhibited lower density (1799 to 1645 kg/m3) and improved thermal properties (0.54 to 0.36 W/m.K) due to the development of porosity during the firing process. While the degradation of organic components was a concern, it was determined that all organic components were completely degraded below 650 °C and the bricks matured at 950 °C. The study concluded that the use of PKS as a partial replacement for clay in brick manufacture is a viable solution for waste management.