Search Results (21)

Concrete is the most used material worldwide, with cement as its essential component. Cement production, however, has a considerable environmental footprint contributing nearly 8% of global CO₂ emissions, largely from clinker calcination. This review aims to examine strategies for reducing these emissions, with a particular focus on alternative materials for producing magnesium phosphate cements (MPCs). Specifically, the objectives are first to summarize mitigation pathways, such as CO₂ capture, energy efficiency, and alternative raw materials, and second evaluate the feasibility of using industrial wastes and by-products, including low-grade MgO, tundish deskulling waste (TUN), boron-MgO (B-MgO), and magnesia refractory brick waste (MRB), as MgO sources for MPC. The review highlights that these materials represent a promising route to reduce the environmental impact of cement production and support the transition toward carbon neutrality by 2050. Full article

The construction industry is responsible for 39% of global CO₂ emissions related to energy use, with cement responsible for 5–8% of it. Limestone calcined clay cement (LC³), a ternary blended binder system, offers a low-carbon alternative by partially substituting clinker with calcined clay and limestone. This study investigated the use of waste clay brick powder (WBP), a waste material, as a source of calcined clay in LC³ formulations, addressing both environmental concerns and SCM scarcity. Two LC³ mixtures containing 15% limestone, 5% gypsum, and either 15% or 30% WBP, corresponding to clinker contents of 65% (LC³-65) or 50% (LC³-50), were evaluated against general purpose (GP) cement mortar. Tests included setting time, flowability, soundness, compressive and flexural strengths, drying shrinkage, isothermal calorimetry, and scanning electron microscopy (SEM). Isothermal calorimetry showed peak heat flow reductions of 26% and 49% for LC³-65 and LC³-50, respectively, indicating a slower reactivity of LC³. The initial and final setting times of the LC³ mixtures were 10–30 min and 30–60 min longer, respectively, due to the slower hydration kinetics caused by the reduced clinker content. Flowability increased in LC³-50, which is attributed to the lower clinker content and higher water availability. At 7 days, LC³-65 retained 98% of the control’s compressive strength, while LC³-50 showed a 47% reduction. At 28 days, the compressive strengths of mixtures LC³-65 and LC³-50 were 7% and 46% lower than the control, with flexural strength reductions being 8% and 40%, respectively. The porosity calculated from the SEM images was found to be 7%, 11%, and 15% in the control, LC³-65, and LC³-50, respectively. Thus, the reduction in strength is attributed to the slower reaction rate and increased porosity associated with the reduced clinker content in LC³ mixtures. However, the results indicate that the performance of LC³-65 was close to that of the control mix, supporting the viability of WBP as a low-carbon partial replacement of clinker in LC³. Full article

This paper presents a study of the effect of the type of exterior cladding material of a building façade on the amount of sound reflection. It was verified whether there is a sound field undisturbed by reflections, similar to the free field, at a distance of 3 m from the building façade. Sound reflections from three building façade structures were tested: clinker brick, mineral plaster, and hard HPL. An equal geometry of the measuring field at selected real objects was used. It was determined that the differences in sound level results measured at distances up to 2 m and more than 2 m from the building façade are lower than the −3 dB correction specified in ISO 1996-2. Significant differences were observed comparing the measured sound level values in the undisturbed sound field with the levels recorded at a distance of 3 m from the building façade. It was proposed that the results of measurements made to control the levels of permissible noise in the environment should not be subject to the −3 dB correction. Full article

The article presents an analysis of the influence of building materials on the propagation of an electromagnetic wave and the values of the electric field intensity. The topics of the analysis were two types of walls (partition and load bearing) built of different building materials. Different variants of walls were considered due to the building material used: concrete, aerated concrete, solid brick, clinker bricks, and three types of hollow bricks. The requirements for structures in terms of wall thickness were taken into account. The article, using concrete as an example, also describes the influence of changes in the electrical parameters of the building material on wave propagation and the values of the field. The results concerning the influence of complex materials, such as hollow bricks, on the non-uniform distribution of the electric field were also included. Due to the different percentage share of ceramic mass in hollow bricks, the article discusses its influence on the values of the field, taking into account the variability of conductivity. The analysis was performed using the Finite Difference Time Domain (FDTD) method. The results were compared with the analytical solution. The analysis, among others, showed that with the increase in the ceramic mass in bricks, the electric field values are higher but result in an uneven distribution of the field. Using the example of hollow bricks used to build load-bearing walls, it was observed that a small modification of the hollows practically does not affect the field intensity (the difference is approx. 2%). When planning the installation of wireless networks, the best solution is walls made of ceramics with a large number of hollows, where the ceramic mass constitutes only approx. 30%. A multivariate analysis allows for a better understanding of field phenomena inside single-family homes. Full article

This article presents a numerical analysis of the effects related to the propagation of electromagnetic waves in an area containing a non-ideal, non-uniform, and absorbing dielectric. The analysis concerns the influence of electrical parameters, the structure of the building material, and the layering of the wall on the values of the electric field intensity. A multivariate analysis was carried out with different conductivity values. Homogeneous materials (e.g., solid brick) can be analyzed using the analytical method. In the case of complex materials containing, e.g., hollows (brick with hollows, hollow block), it is necessary to use the numerical method. The FDTD (finite difference time domain) method was used to assess the dependence of the electric field intensity on the layering, the length of hollows in bricks, and the material loss. In order to check the correctness of the adopted numerical assumptions, a series of tests related to the discretization of the model was carried out. The article also presents the influence of changing the length of hollows in bricks on the values of the electric field intensity at a frequency of 2.4 GHz. The instantaneous field distributions and maximum values of the electric field intensity are presented. In the model with a two-layer wall, regardless of the conductivity, the field values were the same for the two models, where the difference in the percentage of ceramic mass in the brick was 8%. A 12% decrease in the percentage of ceramic mass in the brick resulted in a 15% increase in the value of the area between a single-layer and a double-layer wall made of clinker bricks. At a conductivity of 0.04 S/m for a single-layer wall, the field values were similar for all brick variants. Full article

In this paper, a new way to obtain photoactive cements was presented. In this method amorphous TiO₂ is added to a cooler during the cooling of the cement clinker (Górażdże company) during cement production. Amorphous TiO₂ was taken from the installation for obtaining titanium dioxide using the sulphate method. During the study, amorphous TiO₂ was added to the clinker at 300, 600, 700, and 800 °C. The properties of the obtained cement were tested during the bending and compressive strength. The initial and the end of setting time was also measured. The adhesion of the obtained materials to concrete block, ceramic brick, and plasterboard were also evaluated. The photocatalytic activity of the obtained materials was studied during NO and BTEX (benzene, toluene, ethylbenzene, p-, m-, o-xylenes decomposition) decomposition. Cement with 5 wt% TiO₂ added to the clinker at 700 °C had the highest photocatalytic activity and the best mechanical properties. Full article

Regenerated magnesia-calcium brick samples with different aluminium oxide (Al₂O₃) contents were prepared using spent magnesia-calcium bricks and fused magnesia as the main raw materials and Al₂O₃ powders as the additive. The phase compositions, microstructures, room temperature, hot flexural strength, and kiln coating adherence of the regenerated samples were investigated. This indicates that the Al₂O₃ content increased, mainly resulting in the content of tetracalcium aluminoferrite (C₄AF) and tricalcium aluminate (C₃A) increasing in the regenerated samples. The bulk density, room temperature flexural strength, and kiln coating adherence all increased, whereas the hot flexural strength and corrosion resistance to cement clinker both deteriorated with an increase in the Al₂O₃ content. This was because, on the one hand, the low melting point phases of C₄AF and C₃A improved the sinterability of the regenerated samples during the burning stage, and on the other hand, they melted or existed in the liquid phase at the experimental temperature, which degraded the hot flexural strength and corrosion resistance but enhanced the kiln coating adherence as the wettability of the liquid phase. The content of Al₂O₃ in the regenerated magnesia-calcium brick should not be higher than 1.1 wt.%, considering its comprehensive performance for cement rotary kiln. Full article

The article analyzes the impact of different filling materials for a seasonal heat storage stack that can be used to heat an innovative plus-energy house in Poland. The storage medium is of the sensible heat type. Twelve filling materials and nine thermal insulation materials readily available in the local market were analyzed. Seven variants comprising a combination of the stack’s filling and thermal insulation materials were selected and then grouped into three classes: advanced, medium, and simple technology. Using a mathematical model, energy analysis of the year-round operation of the HVAC installation in the analyzed building was performed for each of the seven variants. The conducted analyses revealed that for each combination of filling and thermal insulation material, there is an optimal maximum temperature of the stack, at which the volume of the stack is the smallest or its costs are the lowest. The obtained results were evaluated to determine the ideal variant combination, and two solutions were recommended: clinker brick and fireplace wool, for which the stack volume is 23 m³ and the total cost is EUR 12,500; and concrete block and glass wool, for which the stack volume is 27 m³ and the total cost is EUR 1700. Full article

The purpose of this work was to investigate the effect of the burning environment on the properties and phase composition of clinker-based ceramic specimens made from loam with diatomite and bentonite clay in order to develop technological parameters for the manufacture of clinker products. The main raw material used for the experiments was local fusible loam from the Almaty deposit, which is the basis for the production of 75 and 100 grade ceramic bricks. Diatomite from Utesai deposit (Aktobe region) and highly plastic bentonite clay from Darbazin deposit (Turkestan region) were used as additives. Loam and bentonite clay were applied after grinding and sieving through a 1 mm sieve. Diatomite was applied after grinding and milling until it had completely passed through a 0.315 mm sieve. The raw materials are mixed after dosing, and then water is added in the amount required until a pliable mass is obtained. To investigate the properties of the products, standard cylinder samples were prepared with a diameter of 50 mm and a height of 50 mm. The cylinder samples were pressed on a hydraulic press at a pressure of 2–4 kN. The samples were dried in a desiccator at 95–100 °C for 2 h. After drying, the products were burning in a muffle kiln. The analysis of the properties of the burned products showed that the optimum ratio in the ceramic mixture of loam and diatomite to loam and bentonite clay is 85%:15%. After burning in a slightly oxidising environment at 1170 °C, the ceramic specimens correspond to Class 2 for the medium-density and compressive strength grades M 400 and M 500 (GOST 530-2012 (Government standard). X-ray diffractometric analysis showed that the products contain augite, quartz and anorthite as crystalline phases, with the former predominating. After burning in a reducing atmosphere, at 1170 °C, the properties of the samples have higher values compared to the samples burning in a weakly oxidising atmosphere. The resulting properties, according to the regulations, are characteristic of clinker bricks (DIN V 105-1 (technical requirements for clinker façade bricks). After burning in a reducing environment, the phase composition of the products changes qualitatively; in addition to augite and quartz, albite, diopside, orthoclase and haematite are present in the samples. Full article

During the MoDeCo2000 scientific and research project on mortars used in the territory of the Roman Danube Limes in Serbia, the biggest challenge was the quest for the provenance of raw materials. The area where Viminacium, the largest city in the province of Moesia Superior developed, with millennial continuity of land use and settlement, was selected as research case study and is presented in this research. People throughout history have always used what they had at hand, and the building remains were not only reused but also recycled for new constructions. Thus, the building material of Roman Viminacium has survived in the landscape through the in situ preserved remains of Roman buildings, as well as in the structures from the later periods, up to today. To the best of our knowledge, the use of natural sediments baked during the self-combustion or combustion of underneath layers (coal in our case) for the purpose of construction was extremely rare in the Roman Empire. In this study, we follow the presence of this type of material precisely in Viminacium construction, naming it natural brick, while focusing on its potential use in lime mortars whose production was perfected in the Roman period and has never been surpassed afterward. Archaeological contexts in which this material was found have been studied, along with simultaneous work in the laboratory and in the field during the research and experimental use of the natural brick in lime mortars. We sought to determine whether this material could have been recognised by Romans in Viminacium as a potential valuable pozzolanic component of mortar, along with or instead of fired brick, being locally available and recyclable. The final confirmation of its pozzolanic features and later discussion open completely new directions for the future research of Viminacium lime mortars. Full article

Clinker bricks were popular as a facade material in the United States between the 1890s and the 1930s. However, this material was unknown to Chinese builders and was seldom found in Chinese modern architecture from 1840 to 1949. The Smart Memorial Gymnasium built in the years 1934–1937 in the Tiancizhuang Campus of Soochow University (Suzhou, China) is one of the rare examples of a building featuring clinker bricks in modern China. Notably, those clinker bricks were not imported but locally manufactured. Despite the heritage significance of the Smart Memorial Gymnasium as part of a major historical and cultural site protected at the national level in China, the history and characteristics of those historical bricks have remained virtually unexplored. This study first provides a historical analysis of those bricks, giving insights into the general knowledge of this construction material around that time based on British and American historical sources from the 19th and 20th centuries, with a focus on historical treaties and documents. This analysis sheds light on the raw materials mixtures of clinker bricks, their manufacturing processes, and their architectural applications at the time. Moreover, this study presents a physicochemical analysis of the clinker bricks employed at Soochow University, focusing on the correlation between historical studies and physicochemical characteristics, as well as the materials’ characteristics that respond to the natural environment. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and total immersion tests were employed to investigate the physicochemical properties of the bricks at various locations of the Smart Memorial Gymnasium facades. Our findings deepen the knowledge and understanding of clinker bricks transferred from the West to China in the early 20th century. Additionally, our results reveal the chemical composition and physical characteristics of different types of clinker bricks used in the Smart Memorial Gymnasium, outlining practical implications and future research directions. Overall, this study lays a foundation for the heritage recognition and conservation of Chinese clinker bricks. Full article

Lead–zinc tailings are the typical solid wastes in mines with high yield and low utilization rates in some countries at present. They are mainly stockpiled in tailings reservoirs, occupying massive land resources and threatening the health of the environment. One of the advantages of building material production in sustainability is the ability to utilize large amounts of industrial solid wastes, and the use of lead–zinc tailings in building materials is an effective way to meet the dual needs of environmental protection and economic development. This paper reviews the progress of utilizing lead–zinc tailings as building materials and mainly summarizes the status of lead–zinc tailings in cement, geopolymer, concrete, building brick, and foam ceramic. According to previous research, lead–zinc tailings contain large amounts of silica–alumina oxide, which can be used in the production of cement clinker. The addition of lead–zinc tailings to the sintered material can reduce the sintering temperature. The active components contained in lead–zinc tailings can be used in concrete instead of cement or in the preparation of geopolymers. Meanwhile, lead–zinc tailings can also be used as a fine aggregate. However, there are few studies on the durability of building materials with lead–zinc tailings. Additionally, most of the research results of building materials are in the laboratory stage, which are difficult to be promoted. In view of these problems, corresponding suggestions and prospects are given in the end in order to provide a reference for the research on the utilization of lead–zinc tailings. Full article

The cement industry is one of the most developed industries in the world. However, it consumes excessive amounts of natural resources and can negatively impact the environment through its by-products: carbon dioxide (CO₂), cement clinker dust (CKD) and cement bypass dust (CBPD). The amount of dust generated in the cement clinker production process depends largely on the technology used. It typically ranges from 0 to 25% by weight of the clinker, and a single cement plant is capable of producing 1000 tons of CBPD per day. Despite practical applications in many areas, such as soil stabilisation, concrete mix production, chemical processing or ceramic and brick production, the dust is still stored in heaps. This poses an environmental challenge, so new ways of managing it are being sought. Due to the significant content of free lime (>30%) in CBPD, this paper uses cement bypass dust as a binder replacement in autoclaved silica–lime products. Indeed, the basic composition of silicate bricks includes 92% sand, 8% lime and water. The investigation shows that it is possible to completely replace the binder with CBPD dust in the autoclaved products. The obtained results showed that all properties of produced bricks were satisfactory. The study concluded that many benefits could be achieved by using cement bypass dust in the production of bricks, including economic bricks for building, reducing the dependency on natural resources, reducing pollution and reducing negative impacts on the environment. Full article

Sulfate attack in concrete structures significantly reduces their durability. This article reports the experimental findings on the effects of sodium sulfate on limestone calcined clay cement (LC³) in an alternate wet and dry media. The samples underwent wet–dry conditions of 28 cycles. Two types of LC³ were studied, one made from clay (LC³-CL) and the other made from fired rejected clay bricks (LC³-FR). The composition of each LC³ blend by weight was 50% clinker, 30% calcined clay, 15% limestone, and 5% gypsum. The reference compressive strength was evaluated at 2, 7, and 28 days of age. Then, ordinary Portland cement (OPC) and LC³-CL blends were subjected to alternate wet–dry cycle tests, immersion in a 5% sodium sulfate solution, or in water. For all exposed samples, sorptivity tests and compressive strength were done. The results showed that LC³ blends met the requirements for KS-EAS 18-1:2017 standard, which specifies the composition and conformity criteria for common cements in Kenya. The LC³ blend also had a lower rate of initial absorption compared to OPC. Additionally, LC³ blend also showed good resistance to sodium sulfate when exposed to alternating wetting and drying environment. OPC showed higher compressive strength than LC³ blends for testing ages of 2, 7, and 28 days. However, the LC³ samples utilized in the sodium sulfate attack experiment, which were later tested after 84 days, exhibited higher compressive strengths than OPC tested after the same period. Full article

This study aimed to identify the composition of ceramic mass for the manufacture of bricks with improved properties based on local loam using diatomite and bentonite clay. For the experiments, loam from the Almaty deposit (Kazakhstan) was applied as the primary product, and used for the production of ceramic bricks with grades of 75 and 100. Diatomite from the Zhalpak and Utesai deposits and highly plastic bentonite clay from the Darbazin deposit (Kazakhstan) were used as additives. An analysis of the properties of the burned products demonstrated that supplementation with diatomite and bentonite in the loam lowers the average density and increases the compressive strength of samples burned at 1000 and 1100 °C. Herewith, the optimal amount of diatomite and bentonite clay to add is 15%, with a fractional composition of 0.315–0.16 mm and less than 1 mm, respectively. It was established that the optimal additions of diatomite and bentonite clay to loam make it possible to obtain after burning at 1170 °C samples of ceramic products corresponding to the 2nd class in terms of the average density and compressive strength grades M 400 and M 500. Full article