Properties Of Building Materials Research Articles

Exploring the Cutting Process of Coaxial Phase Change Fibers under Optical Characterization Tests

Urban heat islands (UHI) are a growing issue due to urbanization, causing citizens to suffer from the inadequate thermal properties of building materials. Therefore, the need for climate-resistant infrastructure is crucial for quality of life. Phase change materials (PCMs) offer a solution by being incorporated into construction materials for thermoregulation. PCMs store and release heat as latent heat, adjusting temperatures through phase changes. Polymeric phase change fibers (PCFs) are an innovative technology for encapsulating PCMs and preventing leaks. This study produced PCFs via wet-spinning, using commercial cellulose acetate (CA, Mn 50,000) as the sheath and polyethylene glycol (PEG 2000) as the core. The PCFs were cut using a hot-cutting method at three different temperatures and washed with distilled water. Morphological analysis was conducted with a bright-field microscope, and chemical analysis was performed using Fourier transform infrared spectroscopy (FTIR) before and after controlled washing. Additionally, the washing baths were analyzed by UV-visible spectroscopy to detect PEG. The PCFs displayed a well-defined core-shell structure. Although some PEG 2000 leakage occurred in unsuccessful cuts, cuts at 50 °C showed sealed ends and less material in the baths, making it viable for civil engineering materials.

The Influence of the Comonomer Ratio and Reaction Temperature on the Mechanical, Thermal, and Morphological Properties of Lignin Oil-Sulfur Composites.

Although lignin is a plentiful biomass resource, it continually exists as an underutilized component of biomass material. Elemental sulfur is another abundant yet underutilized commodity produced as a by-product resulting from the refining of fossil fuels. The current study presents a strategy for preparing five durable composites via a simple one-pot synthesis involving the reaction of lignin oil and elemental sulfur. These lignin oil-sulfur composites LOSx@T (where x = wt. % sulfur, ranging from 80 to 90, and T represents the reaction temperature in °C) were prepared via the reaction of elemental sulfur and lignin oil (LO) with elemental sulfur. The resulting composites could be remelted and reshaped several times without the loss of mechanical strength. Mechanical, thermal, and morphological studies showed that LOSx@T possesses properties competitive with some mechanical properties of commercial building materials, exhibiting favorable compressive strengths (22.1-35.9 MPa) and flexural strengths (5.7-6.5 MPa) exceeding the values required for many construction applications of ordinary Portland cement (OPC) and brick formulations. While varying the amount of organic material did not result in a notable difference in mechanical strength, increasing the reaction temperature from 230 to 300 °C resulted in a significant increase in compressive strength. The results reported herein reveal potential applications of both lignin and waste sulfur during the ongoing effort toward developing recyclable and sustainable building materials.

Meta-arch structure: Designed reinforcement cage to enhance vibration isolation performance

In this study, inspired by the mechanical metamaterials with bandgap properties, a new type of meta-arch structure (MAS) for the attenuation of elastic waves is proposed. In this metastructure, the reinforcement cage, typically employed to enhance the tensile properties of building materials, has been redesigned and transformed into a new structure containing circular tubes with embedded resonant microstructures. The vibration reduction performance of the MAS was illustrated by the frequency response analysis in the simulation calculation, and the generation mechanism of the vibration attenuation band was revealed. The specimens of the complex MAS consisting of gypsum, reinforced steel bars, and tubes were fabricated, and the vibration response experiments were carried out to determine the dynamic properties of the novel MAS. The results show that the designed arch structure exhibits a broad vibration attenuation band without sacrificing its structural bearing capacity. Additionally, the robustness of the band gap is demonstrated by analyzing how changes in the positions of excitation and response points influence the band gap. Moreover, the MAS can be customized for specific application scenarios of vibration reduction according to the parameter analysis. Finally, the experimental results closely align with the numerical estimations, confirming the feasibility of the design method for reducing vibrations. This work provides a new method for the development of building structures for vibration and noise control.

Assessment of Cement Mortar Strength Mixed with Waste Copper Mine Tailings (CT) by Applying Gradient Boosting Regressor and Grid Search Optimization Machine Learning Approach

Growing environmental concerns and resource scarcity, the construction industry must investigate sustainable materials that reduce waste while improving building material properties. This study investigates the viability of using waste copper mine tailings (CT) as a partial replacement for river sand in cement mortar, assessing the impact on mechanical strength and developing a predictive model using a Gradient Boosting Regressor (GBR) and Grid Search Optimization (GSO). Copper tailings mix designs ranging from 0% to 50% replacement by volume (river sand) were developed, with a constant cement quantity while varying the proportions of sand and tailings. The experiments were carried out at Poornima University in Jaipur, using standard protocols to prepare specimens and measure their compressive strength for 0% CT to 50% CT as volume percent in the mixture. The results showed that the addition of copper tailings up to 20% (3CT2) had highly increased the mortar strength, while mix design 6CT3 showed the best strength at 30% CT. Beyond this threshold, strength declined, thus indicating an optimal replacement level. In the final step of the research, the GBR-GSO-based machine learning approach was employed for developing the predictive model for compressive strength in mortar with different contents of copper tailing for mix types 3CT and 6CT. The predictions obtained by the developed model were in very good agreement with empirical data, thus supporting the potential of machine learning to predict material performance for guiding the use of unconventional additives in construction. It could be said that this work not only represents the material properties of copper-tailing-infused mortar but also showcases state-of-the-art machine learning techniques in the building materials science domain while opening new paths for more innovative and sustainable building practices.

Preparation and properties of alkali-activated fly ash-waste brick porous building materials

This study explores the development of sustainable porous building materials through the alkali-activation of fly ash and waste clay brick powder. Utilizing Class F fly ash and brick powder from demolished buildings, a series of alkali-activated mortars with varying brick powder replacements (0 % to 50 % by mass) were formulated and analyzed. The results reveal that a 10 % brick powder replacement optimizes the compressive strength, reaching 73 MPa at 28 days, attributed to enhanced nucleation and calcium-rich gel formation. However, higher brick content reduces strength due to the dilution of key reactive materials, with a 50 % replacement leading to a strength of 27 MPa. Porosity increases proportionally with brick content, achieving a maximum of 42 % at 50 % replacement, suggesting potential applications in insulation-centric scenarios. Microstructural analysis confirms the formation of a porous network and identifies the phase compositions and reaction products. This research demonstrates the potential of repurposing construction waste into efficient and environmentally friendly building materials, contributing to waste reduction and offering a greener alternative to traditional practices.

Microorganisms in Red Ceramic Building Materials—A Review

Ceramic materials have a very long tradition of use in construction. Their durability is related to the surface of the material and the action of the corrosive environment. One of the corrosive factors acting on ceramic materials is microorganisms. They can contribute to the deterioration of the technical and performance properties of building materials. Aesthetic, physical, and chemical deterioration are considered to be the main destructive processes in ceramic materials. This work shows how the different types of the most commonly used ceramic materials, i.e., brick and tiles, are damaged. Each of these types is susceptible to microbial growth. Most microorganisms that occur on ceramic materials produce staining substances and thus form coloured biofilms. The direct action of metabolic products secreted by organisms on inorganic substrates is the main cause of chemical biodeterioration. Therefore, this work presents the impact of microorganisms on ceramic building materials.

Performance repair of building materials using alumina and silica composite nanomaterials with electrodynamic properties

Abstract In recent years, the service life of building materials has become the focus of attention. Among them, the service life of concrete and steel bars is particularly affected by the corrosion of external ions (such as Cl−) in the environment. To solve this problem, a new type of composite nanocolloid was prepared through a controllable preparation method. The composite nanocolloid is prepared from aluminum chloride sol and silica sol as raw materials. The prepared colloidal particles have a particle size distribution between 10.5 and 17.5 nm, exhibiting excellent stability and dispersibility. In order to verify the improvement effect of the composite nanocolloid on the properties of building materials, the influence of it on the porosity of concrete and the anti-corrosion performance of steel bars was experimentally studied. The results indicate that the moisture absorption and dehumidification speed of concrete treated with composite nano colloids is slower, and the pore size distribution is mainly concentrated in 100–1,000 nm, indicating that the colloids can effectively optimize the pore structure of concrete. In addition, the processed steel plate samples showed high AC impedance values and low corrosion current logarithmic values in electrochemical testing, indicating that composite nanocolloids have a significant protective effect on the corrosion of steel bars, which can effectively improve the performance of building materials and extend their service life.

Structural Static Evaluation of Historic Stone Building (Case Study: Zahdeh Building in Hebron Old City)

The historical buildings are of great importance, as they represent the architectural heritage and the image of history.Accurate structural analysis of stone buildings is a real challenge, as the mechanical properties of stone and mortarunits are different and unavailable. The aim of the research is assessment historical stone buildings. An experimentalstudy was conducted to determine the mechanical properties of stone building materials and to modelling validation.A numerical modelling was carried out through a non-linear static analysis based on a macro finite element model,using ANSYS. The result obtained of the model of Zahdeh building is that building can bear its loads in its currentcondition, and it also has the ability to bear loads equivalent to two floors. The proposed methods, are suitable forstructural assessment process and can be applied to similar building models to preserve, both architectural heritageand historic buildings.

Research on the resistance of protective coatings for concrete to the effects of atmospheric moisture

The development of the construction industry has led to increased requirements for the operational properties of building materials in general and concrete in particular. Although concrete is designed primarily to withstand structural loads, it must also resist environmental influences to increase its durability. This article presents the results of the influence of the components of protective coatings on the hydro-physical properties of concrete. The edge wetting angle in concrete with a protective coating ranges from 95 to 101 degrees, which is about twice that of uncoated concrete. The mass of concrete under the influence of hygroscopic moisture increases, and after 30 days of exposure, it is 1.1–1.6 wt. % compared to 5.7–5.8 wt. % for control samples. The minimum increase (1.1–1.2 wt. %) is achieved when using coatings with the largest amount of heat-resistant varnish KO-08. The water absorption of the developed coating compositions decreases after 30 days of being in water from 5.2 to 1.6–2.2 wt. % for C20/25 concrete. Low temperatures negatively affect the hydrophysical properties of protective coatings, but only slightly. It has been found that water absorption increases by approximately 20 %.

The Experimental Characterization of Iron Ore Tailings from a Geotechnical Perspective

The mining industry produces large amounts of tailings which are disposed of in deposits, which neglects their potential value and represents important economic, social and environmental risks. Consequently, implementing circular economy principles using these unconventional geomaterials may decrease the wide-ranging impacts of raw material extraction. This paper presents an experimental characterization of iron ore tailings, which are the most abundant type of mining waste. The characterization includes various aspects of behavior that are relevant to different types of use as a building material, including physical and identification properties, compaction behavior and stress–strain properties under undrained monotonic and cyclic triaxial loading. The tailings tested can be described as low-plasticity silty sand materials with an average solids density of 4.7, a maximum dry unit weight close to 3 g/cm3 and a higher angle of friction and liquefaction resistance than common granular materials. The experimental results highlight the particular features of the behavior of iron ore tailings and emphasize the potentially promising combination of high shear resistance and high density that favors particular geotechnical applications. Overall, the conclusions provide the basis for promoting the use of mining wastes in the construction of sustainable geotechnical works and underpin the advanced analysis of tailings storage facilities’ safety founded on an open-minded geotechnical approach.

Investigation of lightweight gypsum based on montmorillonite nanoclay with enhanced insulation properties

PurposeNowadays, thermal comfort plays a prominent role in contemporary construction practices. Appropriate thermal insulation not only offers energy efficiency benefits in buildings but also enhances occupant well-being, comfort, and productivity. Therefore, a comprehensive understanding of the thermal properties of building materials is essential. This research aims to prepare and investigate a lightweight gypsum-based composite incorporating nano montmorillonite with advanced thermal insulation properties, considering both quality and cost-effectiveness while ensuring environmental compatibility.Design/methodology/approachThis study adopts a laboratory experimental approach. A gypsum sample (without additives) and seven samples of gypsum combined with varying percentages of sodium and calcium montmorillonite nanoclays undergo extensive testing and analysis. Subsequently, the properties of these samples are compared.FindingsThe results indicate that adding montmorillonite nanoclays to gypsum composites reduces the density of the tested samples and increases their porosity. Moreover, the thermal conductivity coefficient decreases in these samples, significantly improving the thermal insulation properties of the lightweight gypsum plaster. This improvement is more pronounced in samples containing sodium montmorillonite nanoclay compared to calcium-based samples. Additionally, the investigations reveal that compressive strength decreases with the addition of montmorillonite to the samples.Originality/valueIn this research, laboratory experiments were conducted to investigate the physical and mechanical properties of gypsum plaster with varying percentages of sodium and calcium montmorillonite nanoclays. The studied properties include density, porosity, thermal conductivity coefficient, and compressive strength. Additionally, stress-strain diagrams, elastic modulus, and initial and secondary critical stresses were analyzed for each specimen.

Influence of Subsoil and Building Material Properties on Mine-Induced Soil–Structure Interaction Effect

Soil–structure interaction (SSI) refers to the dynamic interaction between a structure and the surrounding soil on which it rests. The behavior of the soil can significantly affect the response of the building structure. In the context of civil engineering and structural analysis, SSI becomes particularly important when considering the response of structures to dynamic loads such as earthquakes or so-called paraseismic loads, e.g., mining tremors. Several factors contribute to SSI. Soil and building structure material properties, foundation type, and loading conditions are the most important parameters. The article concerns SSI in the case of mining rock bursts in Poland. The influence of changes in site material conditions and building material properties on the SSI phenomenon was investigated. A few variants of different properties of typical construction materials (brick, reinforced concrete, and cellular concrete) in the case of selected representative building structure were considered. The subsoil material properties from the wide range were also taken into account. Numerical three-dimensional finite element method (FEM) analysis was applied. The adopted models of the soil-structure system were verified by data from in situ experimental vibration measurements. A significant influence of the subgrade material and the building structure material on the SSI was demonstrated.

Field Test and Numerical Study of Train-Induced Vibration of Over-Track Buildings Above Metro Depot

AbstractTo maximize the use of urban land, many cities have built buildings above metro depots. However, the low-frequency vibration caused by metro operation affects the lives of surrounding residents, which seriously restricts the further development of over-track buildings. To study this problem, Firstly, the vibration of the metro depot and surrounding sensitive areas are tested on a large actual metro depot in Southwest China, and the rail, sleeper/support column, bearing column, and cover plate are mainly tested. Then, considering nonlinear factors such as mechanical properties of building materials, soil layering characteristics, and artificial viscoelastic boundary, the numerical coupled model of the train-track-depot-building is established, and the simulation data are compared with the test data to verify the accuracy of the numerical model. Finally, the impact of metro operation on the over-track buildings is evaluated. Results show that for the over-track buildings concerned in this paper, the floor vibration near the rail is the strongest, the main vibration frequency of the office building is concentrated in 10–20 Hz, and the maximum Z vibration level (VLzmax) of the office building is 52.02 dB. The main vibration frequency of the residential building is similar to that of the office building, and the superposition of floor vibration energy causes the vibration of the mid-span point to be larger than the vibration of the corner point and the side wall point. The vibration wave of lower floors mainly propagates through the bearing column, and the vibration of the parking garage is larger than other buildings. The research results can provide a reference for the vibration control and design of over-track buildings above the metro depot.

Optimization of mechanical properties for intelligent building materials combining with various steel fiber types and nano-Carbon black

The mechanical properties of building materials has emerged as a novel application criterion. However, the investigation of the influence of different steel fibers (SFs) types and nano-carbon black (CB) on the mechanical properties of intelligent building materials remains limited. In this paper, an orthogonal test is conducted to analyze the mechanical performance of building materials with various types of SF and different factors of SFs and CB content. The single-phase results reveal that the optimal content of SFs for intelligent building materials ranges from 0.20%∼0.80% when combined with air content and mechanical performance indicators, while the CB content range ranges from 0.25 wt%∼0.75 wt%. Additionally, the study employs the orthogonal experimental method to determine the mix proportion for intelligent building materials. The experiment selected orthogonal design conditions with four levels and three factors (including SF types and contents and CB content) and conducts range analysis and variance analysis on the experimental results of each group. The results demonstrate that the compressive strength and splitting tensile strength of building materials are optimized when the contents of shear-type SFs and CB are 0.40% and 0.75 wt%, respectively.

IMPACT OF FREEZE-THAW CYCLES ON BACTERIAL VIABILITY IN CONCRETE

Calcium carbonate precipitating bacteria can improve mechanical and physical properties of building materials. Most commonly, bacteria are used for the crack repair, production of self-healing concrete, or as a cementitious agent for low-strength materials. The favorable effect of bacterial metabolism can only be achieved if the sufficient number of cells remain viable in the structural material. Besides the limited amount of oxygen, extremely high pH level and mechanical pressure on cell walls, bacteria must survive the repetitive freezing and thawing in concrete-type materials. Freezing water may generate additional internal pressure damaging the bacterial cells and suppressing the bacterial activity. In present study, the viability two of bacteria strains (Bacillus pseudofirmus and Bacillus cohnii), was studied under repeated freezing and thawing conditions. It was shown that concrete-embedded bacteria may survive fluctuations of low temperatures and freeze-thaw cycles, compromising approximately 50% of viable spores. This survivability may only be achieved if bacterial spores are protected from the concrete environment itself, for example, spores could be injected to the expanded clay particles and coated with the styrene-acrylate emulsion. These findings confirm that Bacillus pseudofirmus and Bacillus cohnii bacteria could be used in cold climatic regions, retaining viable bacteria spores within the concrete.

IMPACT OF FREEZE-THAW CYCLES ON BACTERIAL VIABILITY IN CONCRETE

Calcium carbonate precipitating bacteria can improve mechanical and physical properties of building materials. Most commonly, bacteria are used for the crack repair, production of self-healing concrete, or as a cementitious agent for low-strength materials. The favorable effect of bacterial metabolism can only be achieved if the sufficient number of cells remain viable in the structural material. Besides the limited amount of oxygen, extremely high pH level and mechanical pressure on cell walls, bacteria must survive the repetitive freezing and thawing in concrete-type materials. Freezing water may generate additional internal pressure damaging the bacterial cells and suppressing the bacterial activity. In present study, the viability two of bacteria strains (Bacillus pseudofirmus and Bacillus cohnii), was studied under repeated freezing and thawing conditions. It was shown that concrete-embedded bacteria may survive fluctuations of low temperatures and freeze-thaw cycles, compromising approximately 50% of viable spores. This survivability may only be achieved if bacterial spores are protected from the concrete environment itself, for example, spores could be injected to the expanded clay particles and coated with the styrene-acrylate emulsion. These findings confirm that Bacillus pseudofirmus and Bacillus cohnii bacteria could be used in cold climatic regions, retaining viable bacteria spores within the concrete.

Средства реализации языкового смысла «признак предмета» в профессиональной сфере «военное строительство»

<p>The article examines the linguistic means of expressing the linguistic meaning of the «feature of the subject» in the military engineering sublanguage. Relative adjectives describing various properties of building materials and their single-root nouns are relevant for the construction sector. Adjectives denoting hydrophysical, thermophysical, physico-chemical, mechanical, chemical, technological, operational and special properties are used to characterize building materials. Quantitative numerals are less likely than ordinal adjectives to participate in the expression of the linguistic meaning of the «feature of the object» and are inconsistent, non-morphologized definitions, however, in the military engineering field they are active in characterizing the quantitative parameters of temperature, thickness, depth, height and other characteristics of construction objects. The onomasiological correlation between relative adjectives and participles in the construction sector is observed in constructions, «adjective name» is «an object with a certain quality»; «adjective name is an object made of a certain material»; «adjective name is an object built of a certain material». It was revealed that speakers prefer the use of relative adjectives to denote the construction materials used; participles — to denote construction technological processes; quantitative numerals — to denote the nomenclature of construction mechanisms. Adjectives and participles as part of terminological combinations represent a contamination of the linguistic meanings of «subject attribute» and «subject».</p>

Preparation of high-performance materials based on carbon nanofibers and analysis of mechanical properties at room and high temperatures

The shortcomings of conventional building materials, such as inadequate tensile strength and fire resistance, have been significantly exacerbated with the emergence of complex and diverse engineering practices. However, the current research on high-performance building materials is still in its nascent stage. Therefore, our study aims to investigate the potential improvements in the mechanical properties of building materials through the incorporation of carbon fiber and nano silica. Specifically, we focus on assessing the mechanical properties of these modified materials at both room and elevated temperatures. Our experimental results demonstrate a notable enhancement in compressive strength. At room temperature, the H2 group exhibited a 15.1% increase in compressive strength, while the H5 group experienced a 7.3% increase. Notably, the compressive strength of the H7 group reached its highest value at 47.13 MPa. Additionally, the H2 group displayed the highest bending strength at 5.18 MPa. Our electron scanning microscopy analysis revealed the uniform dispersion of carbon fibers within the building materials, without any clumping. This suggests that when the dosage of Carbon Fiber reaches 0.6% of the mass of building materials, it can be uniformly dispersed within the mixture. We have also evaluated the performance of the modified materials under high temperatures. It was observed that the prefabricated building materials group experienced a 65% reduction in compressive strength when subjected to 800 °C. Conversely, the carbon fiber building materials exhibited a compressive strength loss of over 62%. Overall, the carbon fiber building materials outperformed the standard building materials under high temperature conditions, with significantly higher compressive strength. Moreover, the modified materials demonstrated an improvement in the residual splitting strength, ranging from 26% to 37% when exposed to temperatures over 800 °C. These findings indicate a substantial enhancement in the mechanical properties of the proposed modified materials. In conclusion, the incorporation of carbon fiber and nano silica into the building materials resulted in substantial improvements in their mechanical properties. These modified materials hold great potential for practical construction projects, offering higher performance and enhanced durability.

Industrial chimneys – as a potential art object

Industrial chimneys – as a potential art object

Influence of calcined dam mud on the thermal conductivity of binary and ternary self-compacting concrete mixtures using the equivalent mortar method

Reducing energy consumption in concrete buildings requires cement-based structural materials that have low thermal conductivity. Moreover, low thermal conductivity is a crucial property of building materials used for thermal insulation to ensure the comfort of building occupants. The research evaluates the effect of using calcined mud (CM) and natural pozzolan (Pz) on the thermal conductivity of self-compacting concrete (SCC). To optimise SCC formulations, the equivalent concrete mortar method has been used. This communication mainly focuses on the equivalent self-compacting concrete mortars (ESCCMs). The current study consists of ten formulations: one control (based on Portland cement) and nine others containing binary and ternary systems of Portland cement, calcined mud, and natural pozzolan with 10%, 20%, and 30% replacement rates . The mixtures were prepared using tests of cement paste and equivalent mortar in a fresh state. Afterwards, they were assessed based on their compressive strength at 14, 28, 90, and 180 days and their thermal conductivity at 28 and 90 days in the hardened state. The self-compatibility, the thermal conductivity, and the mechanical performance results obtained by relevant tests on ESCCMs prove that the ternary systems (Portland cement, CM, and Pz) open up many techno-economic development avenues in SCC applications to be explored.