Firing Temperature Research Articles

Comparative Study between Multiwall Carbon Nano Tube and Carbon Waste from Aluminium Production in the Preparation of Thermally Stable Cementitious Mortar

Objective: The objective of this study is to conduct a comparative investigation into the performance of multiwall carbon nanotube (MWCNT) and carbon wastes (C-waste) derived from the aluminum industry in the creation of thermally stable cementitious mortar. Specifically, the research aims to assess their impact on compressive strength and thermal stability, with a focus on identifying the superior additive for enhancing the properties of cement mortar. Methods: Cement mortar is produced using a blend of CEMIII cement and sand passing through a 1 mm sieve. Various ratios of MWCNT and C-waste, ranging from 0.1% to 0.7%, are incorporated into the mixture. Compressive strength tests are conducted at different intervals, up to 90 days, to evaluate the effects of additives on strength enhancement. Additionally, the resistance to high temperatures is examined by subjecting the mortar samples to firing temperatures up to 700 degrees Celsius. Results: The inclusion of both MWCNT and C-waste leads to improvements in compressive strength values, with the most significant enhancement observed at 0.1% concentration, resulting in approximately 70MPa and 75MPa at 90 days, respectively. Notably, C-waste demonstrates superior physical and mechanical properties compared to MWCNT, along with a lower production cost. Moreover, both additives exceed the specified limits for thermal resistance in mortar, achieving measurements of about 60MPa for MWCNT and 63MPa for C-waste when exposed to firing temperatures of 700 degrees Celsius. These results highlight the higher thermal stability of C-waste relative to MWCNT. Conclusion: In conclusion, this study confirms the efficacy of utilizing C-waste as an additive in cementitious mortar production, showcasing its superior performance over MWCNT in terms of compressive strength enhancement and thermal stability. The findings underscore the potential of repurposing industrial by-products such as C-waste to improve material properties while also addressing environmental concerns and reducing production costs in construction applications.

Anthropogenic warming is a key climate indicator of rising urban fire activity in China

Abstract China, one of the most populous countries in the world, has suffered the highest number of natural disaster-related deaths from fire. On local scales, the main causes of urban fires are anthropogenic in nature. Yet, on regional to national scales, little is known about the indicators of large-scale co-varying urban fire activity in China. Here, we present the China Fire History Atlas (CFHA), which is based on 19 947 documentary records and represents fires in urban areas of China over the twentieth century (1901–1994). We found that temperature variability is a key indicator of urban fire activity in China, with warmer temperatures are correlated with more urban fires, and that this fire–temperature relationship is seasonally and regionally explicit. In the early twentieth century, however, the fire–temperature relationship was overruled by war-related fires in large urban areas. We further used the fire–temperature relationship and multiple emissions scenarios to project fire activity across China into the twenty-first century. Our projections show a distinct increase in future urban fire activity and fire-related economic loss. Our findings provide insights into fire–climate relationships in China for densely-populated areas and on policy-relevant time scales and they contribute spatial coverage to efforts to improve global fire models.

Highly crystalline yttria‐stabilized zirconia and titania thin films on plastic substrates via sol‐gel transfer process

AbstractWe prepared yttria‐stabilized zirconia (YSZ) and titania crystalline thin films on polycarbonate (PC) substrates by the sol‐gel transfer technique that we have developed recently. Precursor gel films were deposited by spin‐coating on a polyimide/polyvinylpyrrolidone mixture layer on Si(100) substrates, and then were calcined at 600°C. The spin‐coating and the calcination were cycled, followed by final firing at 600–1000°C, to obtain 140–190 nm thick, YSZ and titania crystalline thin films. The film densification progressed as the final firing temperature increased, where the porosity calculated from the refractive index decreased down to a few percent. The film thus obtained was heated at 190°C on a hot plate, and a PC substrate was pressed on the film to transfer it to the PC substrate. The transferability quantified by image analysis of the film area was found to be significantly different between the YSZ and titania films. In the case of YSZ films, the area of silicon that was fractured and adhered to the transferred film increased significantly with increasing firing temperature, leading to a decrease down to 0% in the fraction of the successful transfer area without such a damage. On the other hand, the fraction of the successful transfer area remained around 90% irrespective of the firing temperature for the titania films. The surface of the titania films that were fired at 800–1000°C and transferred to PC substrates had voids of several tens nm scale, which may have been formed during anatase‐to‐rutile phase transformation. We thought that the reduced titania/Si(100) contact area due to such void formation facilitated the delamination of the titania films from Si(100) substrates. High temperature firing, which promotes crystallization and densification of films, thus affects differently the film transferability to plastic substrates, depending on the type of films. The work also suggested possible use of titania films as release‐assisting layers.

A tentative study on the effect of tunnel width on the maximum temperature under the ceiling in tunnel fires

Maximum gas temperature under the ceiling in tunnel fires has been studied experimentally and numerically. Full scale burning test in tunnel with length 100 is carried out. Three different pool fires with approximate maximum heat release rate of 0.6, 1.0 and 5MW were set up. The smoke temperature is collected by the Fiber-optic Bragg grating system. CFD simulations were carried out to study the effect of tunnel width on the maximum temperature. By analyzing the experimental and numerical simulation results, a critical point of ratio B/H and two stages concerning the varying of B/H are proposed to clarify the influence of tunnel width, meanwhile we conclude that it is interdependent between the ratio of H/B and the ventilation velocity when discussing the maximum gas temperature in tunnel fires.

Enhancing Physical-Thermal-Mechanical Properties of Biobased Ceramic Composite Utilizing Natural Beta-Tricalcium Phosphate, Glass, and Tricalcium Silicate

Eggshells, a sustainable raw material, accumulate in millions of tons daily after consumption and are utilized across various industries including food, pharmaceuticals, agriculture, and cosmetics. Composed mainly of calcium carbonate (CaCO3) with a purity exceeding 98 wt%, eggshells serve as raw material for producing beta tricalcium phosphate (β-Ca3(PO4)2). The addition of tricalcium silicate cement (C3S) enhances thickening, ductility, and setting properties, facilitating polymerization and solidification through curing and hydration processes. Incorporating soda lime glass powder at varying concentrations (0, 10, 20, 30, 40, and 50 wt%) improves the mechanical and thermal properties of biobased ceramic composite. Higher concentrations of embedded soda lime glass powder have demonstrated increased compressive strength, reduced water absorption, decreased thermal expansion coefficient, and lowered firing temperature. This renders it a promising alternative for replacing and repairing materials in medical applications such as bone grafts and splints.

Preparation and properties of low-temperature self-expanding foamed ceramics utilizing lepidolite mica ore and ceramic tile polishing waste

Foamed ceramics were prepared at temperatures of 1175 °C, 1200 °C, 1225 °C, 1250 °C, and 1275 °C using lepidolite mica ore, ceramic tile polishing waste, and fly ash as raw materials, with borax as a fluxing agent. The main source of the foaming material was determined as SiC, followed by anorthite and iron oxide, based on the X-ray diffraction (XRD) patterns of the raw materials and the thermal analysis (TG-DTA) results of the raw materials and SiC. The effects of the raw material ratio and borax content on the samples' phase composition, compressive strength, microstructure, thermal insulation, and corrosion resistance were systematically studied. The results show that the pore structure of the foamed ceramics sintered at 1225 °C with 25 wt% lithium mica ore, 50 wt% ceramic tile polishing waste and 25 wt% fly ash were uniform. However, based on the above ingredients, 18 wt% borax was added to reduce the firing temperature by 300 °C. After firing at 925 °C and holding for 30 min, the samples' average pore size, bulk density, compressive strength, and porosity were 0.58 mm, 0.66 g/cm3, 10.256 MPa, and 83.1 wt%, respectively. It exhibits good thermal insulation and corrosion resistance, and its performance meets the requirements for building insulation materials, making it an energy-saving and environmentally friendly building material.

Pollutants and weathering compounds on medieval bricks of historic buildings from Brasov (Transylvania, Romania)

Urban pollution significantly influences historic building preservation via chemical, physical, and biological processes. To plan heritage structure restoration, we must study fired brick mineralogy and its correlation with firing temperature. We must also examine how atmospheric pollutants have affected surface composition over time. This study analyzes medieval bricks from seven medieval buildings in Brașov, Romania. We used physicochemical methods (XRD, SEM-EDS, and FTIR-ATR) to identify brick minerals, estimate firing temperatures, and investigate weathering compounds due to pollutants. Samples show quartz, clay minerals (muscovite, illite, palygorskite/smectite anh., kaolinite anh.), feldspars (microcline, orthoclase, albite, andesine), and carbonates (calcite) (for the bricks estimated to be fired at ∼800 °C); sanidine, gelhenite (for the bricks estimated to be fired at ∼950 °C); anorthite, wollastonite, diopside, spinel, mullite (for the bricks estimated to be fired at ∼1100 °C). Weathering varies by mineralogy, firing temperature, location, and pollutants, including efflorescence (CaCO3), black crust (gypsum, calcite), and organic/bio-organic compounds. Mitigation strategies based on physicochemical studies aim to protect cultural heritage from pollution's adverse effects for future generations. This study is vital globally for preserving cultural heritage, offering insights into mitigating the impact of pollution on historic buildings. It aids in developing universal conservation strategies, ensuring our shared past's longevity and aesthetic value.

Compressed earthen blocks using alluvial clays from Mbam: performance comparison using statistical analysis of cement vs heat-stabilized blocks

AbstractIn the present study, a comparison of the thermal-insulation and mechanical performances of cement and heat-stabilized compressed earthen blocks (CEBs) was carried out to determine the factors which influence those properties. The raw clays used consist mainly of kaolinite, orthoclase and quartz. The mechanical strength increased with increase in both the amount of cement added and the firing temperature. However, the responses are better for cement-stabilized CEBs. The thermal insulation of fired bricks is greater than that of cement-stabilized bricks. This difference was related to the decrease in porosity and the formation of continuous-surface. The decrease in thermal insulation is mainly related to the formation of continuous-surface in cement-stabilized CEBs, whereas in the fired CEBs, it is due to the modification of pore volume. The mineralogy of the raw clays is statistically correlated to porosity and continuous-surface development that were confirmed as the main factors in the modification of both the mechanical strength and the thermal insulation. In cement-stabilization, the decrease in insulation is due to the development of continuous surface, while for heat-stabilization, mineral transformations during the sintering reduced continuous-surface formation and the insulation was controlled by both radiation and reduced surface conduction. The influence of the mineralogy of the raw material shows that clay content favours the insulation in fired bricks obtained at T ≤ 1000°C, while sand contents favour densification. In contrast, clay contents reduce the mechanical response of cement-stabilized material due to limited cement–clay interactions. In general, the mechanical response is more favourable in cement stabilization, while thermal insulation is better in fired bricks.

Microwave dielectric properties and LTCC applications of new glass-free molybdate ceramics Li3Ba2Ln3(MoO4)8 (Ln=Gd, Tm)

The traditional solid-state sintering method was employed to prepare Li3Ba2Ln3(MoO4)8 (Ln = Gd, Tm) ceramics, and the impact of firing temperature on the structure, microstructure and microwave dielectric properties of the novel molybdate Li3Ba2Ln3(MoO4)8 (Ln = Gd, Tm) ceramics was examined. XRD and Rietveld refinement outcomes validate the monoclinic system with the C2/c space group for Li3Ba2Ln3(MoO4)8 (Ln = Gd, Tm). For the Li3Ba2Gd3(MoO4)8 ceramic sintered at 800 °C, a εr is 9.42, a Q × f is 16,988 GHz, and a τf is 4.57 ppm/°C. The Li3Ba2Tm3(MoO4)8 ceramic sintered at 800 °C has a εr of 9.74, a Q × f of 25,401 GHz, and a τf of 1.08 ppm/°C. XRD and EDS analyses prove the good chemical compatibility of the co-sintered Li3Ba2Gd3(MoO4)8 ceramic with the Ag electrode. Therefore, the Li3Ba2Gd3(MoO4)8 ceramic is suitable candidate material for LTCC applications.

Post fire performance of galvanized cylindrical shells for buckling failure

This study examines the impact of anti-fire paint with different thicknesses of 100, 200, and 400 microns on the post-fire behavior of cylindrical tanks under external pressure. For this purpose, we investigate the buckling modes of the cylindrical tank specimens after they are exposed to fire. Different fire temperatures of 300, 450, and 600 ℃ were investigated. A total of 22 specimens were fabricated in the laboratory. The specimens have been divided into three groups, the first group without any anti-fire, the second group include the anti-fire paint on their inner skin and the last group have the anti-fire paint both on inner and outer faces of the tank. In the second part of the study, to determine the effects of anti-fire paint numerically, the finite element models were created in Abaqus software. Numerical models were verified by Experimental data, with an error rate at initial buckling 5.4%, overall buckling 6.17% and collapse 7.88%. The results showed that the samples with 100-micron-thick anti-fire paint on both outer and inner surfaces did not show any significant difference compared to unpainted specimens under buckling load. However, the cylindrical specimen with 200-micron-thick anti-fire paint on both outer and inner surfaces was found to be fire resistant up to 450 ℃ and displayed similar behaviors with the perfect one (unpainted and not exposed to fire). Moreover, the specimens with 400-micron-thick anti-fire paint were also found to be resistant to fire up to 450°; however, the collapse loads of these specimens were greater than the overall buckling load of the specimens with 200-micron thick anti-fire paint. Numerical and experimental results show a good agreement, the stress distribution and plastic equivalent strain values were parallel with the buckling load capacity of the specimen. As a result, the thickness of the anti-fire paint directly affects the fire resistance of cylinder steel, and with a validated finite element model, it is possible to predict the paint thickness that can withstand specific fire temperatures in large shell structures.

Exploring pottery origin by composition and technique comparison: a case study at the Daqu burial site, Beijing, China

Scientific analysis of excavated pottery reveals critical archaeological insights, yet data on Han Dynasty pottery remains limited. This study focuses on pottery artifacts excavated from the Daqu burial site in Beijing, renowned for their polychrome decorations and size. Utilizing optical microscopy (OM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray Fluorescence (XRF), this study examined five substrate samples sourced from fragments of pottery towers and ellipse-shaped dishes. All samples exhibited similar inclusions and the same firing atmosphere. The mineralogical analysis indicated that quartz and feldspar are predominant components, with minor constituents like chlorite and kaolinite observed in the coarse pottery of the ellipse-shaped dish. Minor mineral variations suggest differences in firing temperatures. The resemblance between low-value pottery cups and delicate polychrome towers suggests they were crafted locally. These findings advance our understanding of ceramic materials and techniques in late Eastern Han Dynasty Beijing, providing crucial insights for future studies on ancient Chinese economy and society.

Environmentally safe installation for determining the fire resistance of coatings and fire resistance tests of small fragments building structures

Actuality. Taking into account fire statistics, the task of preventing the occurrence and spread of fires is urgent. It is obvious that the fire resistance of building structures, which must be taken into account at the design stage, is of the greatest importance and influence on the development and spread of fires in buildings and structures. Conducting fire experiments makes it possible to obtain the most complete information about the behavior of building structures under fire effects, however, the scale of field tests, labor-intensiveness, energy consumption and damage to the environment prompts the search and development of alternative methods that would ensure the environmental friendliness of the tests, compliance with the conditions of the experiment ( standard fire temperature regime), and at the same time would make it possible to estimate the limit of fire resistance of a building structure in reduced dimensions or to experimentally determine the fire-resistant ability (efficiency) of fire-resistant coatings. Purpose. The main goal of the article is rationale use of an installation for determining the fire-resistant capacity (efficiency) of fire-resistant coatings and fire resistance tests of small-sized fragments of building structures, taking into account the reduction of the harmful load on the environment. Main results. Research has been carried out and the design features of the installation have been substantiated, the principle of which is to heat the inner space of the chamber with the help of electric heating elements, which, unlike liquid fuel (diesel fuel, fuel oil, gas), do not harm the environment. A control unit-module of variable voltage regulation designed to regulate the heating temperature of the radiation panel in the test chamber has been developed. The design of the created test setup makes it possible to increase or decrease the temperature on the heating surface of the test sample, not only with the help of the heating temperature regulator, but also in manual mode, by moving the test sample closer or further away from the radiation panel along the guides. Conclusions. According to the results of experimental tests, it was established that the chamber of the installation warms up uniformly and according to the standardized temperature-time dependence Ts = 345lg (8t+1)+20). At the same time, the temperature regulation process using BP-10 with triac output ensures stable operation of electric heating elements up to temperatures of 1000 °C. A feature of the created installation is the possibility of additional lowering or raising of the temperature on the heating surface of the experimental sample, in case of its deviation during the experiment, by means of approaching or moving away from the sample to the heating panel. The conducted studies confirm the necessary reproducibility of experimental results.

Between Scientific and Sensory Knowledge: Exploring the Enactment of Clay Sensibilities Among Clay Artists in Singapore

This article explores how clay artists in Singapore utilize both their scientific and sensory knowledge of clay-making in producing clay works. Based on a study of the biographies and sensory experiences of clay artists, clay artists rely simultaneously on their scientific knowledge and understanding of clay firing processes, temperatures, and glazing, together with their sensory judgment and experience of the same set of processes, to produce clay works of different design, effect, and form. Thermoreceptive understanding and knowledge of how clay reacts and behaves toward the different styles of firing are deployed by clay artists through both a scientific calibration of temperature, as well as one’s sensory evaluation—including visual and sonic judgments—of fire-control toward producing intended textures and forms. Through making sense of how scientific and sensory knowledges are concurrently enacted but not without contradictions, we make a case for how creative clay work-making straddles across different domains of learning, knowledge use, teaching, and evaluation emerging through kairotic moments. The article contributes to extant debates on art worlds, material culture, sensory knowledges, and embodied experiences through clay work as a medium of analysis.

Fingerprinting Ceramics from the Chalcolithic Santa Vitória Enclosure (SW Iberia)

The Santa Vitória Chalcolithic site (southern Portugal) prompts several questions related to the provenance and production technology of artefacts. Archaeological ceramics from two sections of Ditch 1 of the Santa Vitória site were studied by neutron activation analysis and X-ray diffraction for the first time, with the main goal of contributing to the contextualization of the artefacts and better understanding their production processes/technologies and the provenance of raw materials. The results point to a local production of ceramics, since their mineral phases reflect the geological contexts around the archaeological site. The mineralogical assemblage indicates a firing temperature below 850 °C. Iron is the better discriminator of ceramics from both sections, which could be related to the addition of different proportions of temper grains during the ceramics’ production. Although trace elements do not serve as discriminating geochemical indicators for the analyzed samples, they do imply a slightly higher heterogeneity in the composition of the ceramic paste from section 2. The negative Eu anomaly found in two samples is in accordance with the lower contents of Na2O, related to plagioclase weathering. Detailed studies on ceramics and potential raw materials are foreseen to assist in discussing the role of this Chalcolithic archaeological site at a regional level.

The Influence of Short-Term High Temperature Environment on the Non-Uniform Distribution of Ferrite Grain Size in 40 mm-thick Q345 Steel

In order to reveal the non-uniform distribution of grain size in thick direction for engineering heavy plate, microstructure of 40 mm-thick Q345 steel was observed and measured under different short-term high temperature environments formed by fire. Moreover, the influence of the short-term high temperature environment was revealed on the distribution of ferrite grain size in the Q345 steel. Under different fire service environments, there was a log-normal distribution relationship between the distribution parameter Nf (number of ferrite grains) and df (average grain diameter), as well as ρAf (area fraction density) and df, at different positions along the thickness direction. However, the statistical results are greatly affected by the length of the statistical interval. When df is about 4 to 6 times the length of the statistical interval, the statistical accuracy is higher. By using nonlinear fitting method, multiple non-uniform distribution empirical models including Nf-df empirical formulas and ρAf-df empirical formulas were established at different positions along thick direction under various fire environments. Furthermore, the interrelationships between fire temperature T and Nf , T and ρAf , fire duration t and Nf , t and ρAf were revealed, respectively.

Production of lightweight expanded aggregates from smectite clay, palygorskite-rich sediment and phosphate sludge

Abstract Lightweight expanded clay aggregates (LWAs) are porous materials with low density and high strength (EN-13055-1), and they are important in sustainable construction through their lightweight nature and ability to provide thermal or acoustic insulation. The objective of this work was therefore to evaluate the preparation of LWAs using a smectite clay (M1 formulation), whose application in common ceramic production is difficult. An alternative approach was proposed for the valorization of phosphate sludge and a palygorskite-rich sediment by mixing them with expanded clay (M2 formulation) for LWA production. This could result in economically cost-effective products with significant environmental benefits. Pellets were prepared and fired at various temperatures (1100°C, 1125°C and 1150°C), and relevant properties such as bloating index, density, water absorption and compressive strength were determined. Additionally, the microstructure, mineralogical transformations and phase compositions under various sintering temperatures were investigated. Increasing the temperature from 1000°C to 1150°C significantly improved the expansion properties of LWAs, and 1150°C seemed to be the optimal firing temperature at which the best expansion properties were achieved. In addition, the incorporation of the selected waste improved the properties of the final products, leading to lower density, greater strength and greater bloating with the development of the internal pore structure as compared to the LWAs without this addition. Because of their low density (0.6 g cm–3) and sufficient compressive strength (0.86 MPa), the manufactured LWAs can be used in construction (as insulating panels or in lightweight concrete) and in green roofs.

Study on fire temperature fields of air-supported membrane structures considering thermal–fluid–solid coupling and boundary correction

The study analyzed and compared the effects of thermal–fluid–solid coupling dynamic boundary conditions and traditional fixed-boundary conditions on the distribution of the temperature field under fires. The feasibility of simulating the temperature field distribution was confirmed by using thermal–fluid–solid coupling dynamic boundary conditions. Then, the traditional temperature field analysis methods were corrected by including a flow-based heat exchange coefficient, and the feasibility of this approach was also confirmed. The fire temperature field in a rectangular air-supported membrane structure was analyzed through parameterization. The fire temperature field model of the air-supported membrane structure was established using temperature field data fitting. Furthermore, the study explored the high-temperature material properties of P-type membranes and analyzed and compared the temperature field of the air-supported membrane structure with time-varying mechanical properties of the membrane material to that without time-varying properties.

Using ceramic demolition wastes for CO2-reduced cement production

This study focuses on assessing the pozzolanic potential of two types of ceramic demolition waste, namely terracotta roof tiles and sanitary porcelain, as substitutes for traditional calcined clays in blended and limestone calcined clay (LC3) cement production. Experimental methods employed include the modified Chapelle test and XRD for pozzolanic activity evaluation, flexural and compressive strength tests, capillary absorption measurements, and SEM for microstructure analysis. Mortars containing 10%, 20%, and 30% ceramic powders and 5%, 10%, or 15% limestone filler were tested. The findings showed that porcelain powders exhibited lower pozzolanic activity due to their lower surface area and higher firing temperature of the material. Up to 20% substitution of OPC with terracotta had minimal strength impact, with a 103% strength activity index (SAI) at 90 days. Ultrafine terracotta powder showed promise in LC3 production with up to 30% OPC substitution, achieving a 97% SAI after 90 days. The poor mechanical properties of porcelain-containing mortars were explained by surfactants present in sanitary porcelain. This research informs the cement and processing industries on the potential use of specific ceramic demolition waste materials in eco-cement production, offering insights into blended pozzolanic cements and LC3 formulations, with the goal of reducing the carbon footprint of cement manufacturing.

μ-Raman spectroscopy as a useful tool for improving knowledge of ancient ceramic manufacturing technologies

In recent decades, μ-Raman spectroscopy has become a powerful technique for studying ceramics, with the advantage of performing fast, reproducible and reliable analyses that provide effective information on ceramic technology. In the present paper, the potential of μ-Raman spectroscopy was evaluated by comparing the results of spectroscopic analyses with a wide range of conventional compositional and mineralogical analyses. Particular fragments of pottery from the archaeological site of Pollena Trocchia (Campania, Italy), characterized by a variegated color zonation, a symptom of uncontrolled firing conditions, were subjected to in-depth analytical investigation. Data from the μ-Raman measurements were in very good agreement with the analytical set of conventional analyses and permitted to better constrain the firing temperatures, evaluate changes in the oxidative steps, and assert the provenance of volcanic raw materials. The results illuminated that pottery was crafted by mixing a low-CaO base clay with volcanic temper from the environs of Vesuvius and fired in a not well-controlled firing atmosphere, which determined the development of Fe(III) oxides at rims of sherds and Fe(II)-bearing phases at cores. Moreover, even in the absence of newly-formed minerals, firing temperatures were estimated between 900 and 950 °C, as suggested by the mineralogical and spectroscopic evidence of the prograde 10 Å dehydroxylated phyllosilicates.

METHODOLOGY FOR STUDYING THE FIRE PROTECTION ABILITY OF A FIRE PROTECTION COATING BASED ON POLYSILOXANE AND OXIDES OF ALUMINIUM, TITANIUM, AND CHROMIUM FOR STEEL BUILDING STRUCTURES

Fires and their negative consequences are a significant problem today. The final report of the World Fire Statistics Centre in 2023 shows that an average of 3.7 million fires occurred annually between 1993 and 2021. The fire resistance of building structures has paramount importance and influence on the development and spread of fires in buildings and structures, which needs consideration at the design stage. Particular attention should be paid to metal structures when used in construction since their fire resistance limit is about 15 minutes, depending on the profile and cross-section of the structure, and this, in turn, limits their use in buildings and structures where the fire resistance class of structures is REI 15. A way to increase the fire resistance class of a steel building structure is its fire protection implemented using dedicated means that protect the steel structure from the effects of high fire temperatures. The study aims to develop a methodology and determine the heating time of prototypes of steel plates with a fire-retardant coating based on polysiloxane and oxides of aluminium, titanium, and chromium to a critical temperature depending on the coating thickness (0.3, 0.45, 0.6, 0.8 mm) and the thickness of the steel plate (0.3, 0.5, 0.8 cm). To determine the fire protection capacity of the developed fireproof coating, we used the method regulated by clause 7.4 of DSTU-N-P B V.1.1-29:2010 ‘Fireproof treatment of building structures. General requirements and control methods’. The authors have developed a methodology for conducting experimental studies of the effectiveness of fire protection coatings using an installation for determining the fire protection capacity (effectiveness) of fire protection coatings, the principle of which is to heat the interior of the installation chamber using electric heating elements. The heating time of the prototypes of steel plates with the developed fire protection coating to the critical temperature was determined, depending on the coating thickness and the thickness of the steel plate. We found that the extreme temperature in a steel plate with a thickness of 0.3 cm is reached at 23, 34, and 46 minutes with a coating thickness of 0.3, 0.45, and 0.6 mm, respectively. Experimental studies of steel plates with thicknesses of 0.5 and 0.8 cm have shown that with an increase in plate thickness at the same values of the thickness of the fire protection coating, the time to reach the extreme temperature increases by about 1 minute. At a coating thickness of 0.8 mm, for steel plates with thicknesses of 0.3 and 0.8 cm, the temperature on the unheated surface of the prototype did not reach the extreme value.Given the results obtained, it will be relevant to solve the inverse problem of thermal conductivity to determine the thermal and physical characteristics of the coating based on numerical data from experimental studies. Keywords: research methodology, standard temperature regime, fire protection coating, steel building structure.