Hasil untuk "Systems of building construction. Including fireproof construction, concrete construction"

A. M. Abd El Fattah, A. O. Amao, K. Riding et al.

Abstract This study investigates the long-term durability of concrete incorporating fly ash (FA) and limestone powder (LP) when subjected to simultaneous sulfate and chloride ion attack. Three concrete mixtures—100% ordinary portland cement (PC), 25% FA-blended concrete, and 15% LP-blended concrete—were immersed in 5% sodium sulfate (S) and combined 5% sodium sulfate + 3.6% sodium chloride (SC) solutions at 30 °C for a period of two years. Ion ingress, phase evolution, and microstructural changes were assessed using ion chromatography, X-ray diffraction (XRD), and scanning electron microscopy (SEM/EDS). Results showed that the presence of chloride ions significantly accelerated sulfate ingress and compound formation. The LP mix exhibited the most severe deterioration, characterized by elevated formation of expansive phases such as ettringite and gypsum, leading to internal cracking and substantial compressive strength loss under SC exposure. In contrast, the FA mix demonstrated superior performance due to enhanced chloride-binding capacity, pozzolanic C–S–H formation, and reduced permeability, which limited deleterious phase development. The findings highlight that while LP improves early sulfate binding, its limited chloride-binding capacity increases vulnerability to sulfate–chloride deterioration. FA-modified concrete offers a more durable alternative for structures exposed to aggressive multi-ion environments by enhancing microstructural stability and long-term performance.

Kamal A. R. Ismail, Fátima A. M. Lino, M. Teggar et al.

Buildings account for a significant portion of global energy consumption, estimated at 30-40%, and also contribute to greenhouse gas emissions. Energy consumption in a building is mainly thermal (natural gas) and electrical. This energy is usually used for heating water, cooking, illumination, ventilation and air conditioning, powering appliances, floor heating, and other activities. These activities were examined, and their substitution by solar-based energy sources was reviewed. To achieve this objective, an extensive literature review across Scopus, Direct Science, and Web of Science in relevant areas, including building energy needs, thermal and visual comfort, and construction materials and components, was conducted. Innovative construction materials, including mortars, bricks, concrete, and components such as Trombe walls, can enhance thermal efficiency and thermal comfort. Solar energy can replace fossil-based energy for the provision of hot water, and hot fluid for air conditioning absorption chillers systems. Building components such as thermally efficient windows (double-glazed, evacuated, etc.), bright windows, and facades can help maintain a thermally and visually comfortable indoor environment. Electric energy for buildings’ services, such as illumination, ventilation, and other services, can be provided by solar PV panels. The review shows that solar energy can significantly contribute to decarbonizing buildings’ energy needs, maintaining passive thermal and visual comfort, and reducing emissions. The review indicates that a solar air conditioner with a 12,000 BTU cooling capacity can save 8-28% of energy and reduce emissions by 7.74-28.27%. It also showed that selecting windows and facades is a critical issue. A comparison of the energy-saving of thermo-chromatic, double-glazed, and clear glass windows indicated a reduction of 8.91% to 10.96% in energy consumption due to double-glazed windows and a reduction of 20.22% to 24.19% due to thermo-chromatic windows. Smart windows with photovoltaic electrochromic (PV-EC) enabled a useful daylighting illumination of about 75.26% and energy saving of about 15.79% compared to ordinary windows. It is recommended that applications such as hot water, water distillation, illumination, electricity, and air conditioning be powered by solar energy. In the construction of buildings, thermally efficient materials and components should be prioritized. To promote building decarbonization, it is necessary to reduce the cost of materials, create financial incentives and low-interest grants for retrofitting, and create public policies to promote solar-based energy applications in buildings.

Yi-Rong Chen, Shugao Lin, Y. Tsay

To achieve the 2050 net-zero goal in Taiwan, the Kaohsiung City government has committed to achieve a 30% reduction in greenhouse gas emissions by 2030. The Kaohsiung House Project was initiated in 2014 to enhance the sustainability and living quality of private residential buildings across the Kaohsiung city. The project offered incentives such as additional floor area for incorporating green building features, including vertical greenery, renewable energy systems, and universal design elements. However, the scope was limited to operational carbon reduction (i.e., energy conservation), and the embodied carbon reduction was not included in the Kaohsiung House Project. As a result, the structure system design plays the most important role in reducing embodied carbon, and the LEBR rating can rise from 1 to 3 levels via material changes. Changing the interior floor from ceramic tile to stone and changing the concrete framework from wood to metal will increase the construction cost. Using low-carbon concrete and changing interior walls didn’t show a significant difference in construction cost. Changing the exterior finishing from ceramic tile to painting will reduce the cost and embodied carbon.

Asit Bayen, J. Pooni, D. Robert et al.

L. Vozniuk, S. Shcherbakov

Since the end of the first quarter of the twenty-first century, social processes have been characterized by increasing dynamics, requiring a high level of mobility and adaptability from the construction industry. In response to these challenges, the emergence and continuous development of construction-scale 3D printing technology have created prerequisites for fundamental changes in construction practices. This technology enables the realization of buildings and structures with complex geometric forms that were previously difficult or economically impractical to construct using traditional methods. The use of automated construction processes based on pre-designed digital models allows the transformation of construction from a static, labor-intensive industry into a flexible digital ecosystem capable of rapidly adapting to changing functional and spatial requirements. At the same time, the transformation of construction technologies is not limited solely to structural elements such as load-bearing walls, partitions, or floor systems. Additive manufacturing technologies also open new possibilities for shaping the internal architectural environment by enabling the fabrication of complex bionic elements with optimized geometry. Such forms were previously considered technically infeasible or excessively expensive. As a result, 3D printing technology has the potential to change the role of architectural and structural elements, allowing them to function not only as passive components but also as active elements of an integrated built environment. Despite the rapid technological progress in construction 3D printing, the scientific basis for the structural behavior of 3D-printed load-bearing systems remains insufficiently developed. In particular, there is a lack of experimental data concerning the load-bearing capacity, deformability, and failure mechanisms of such structures. Existing design standards and regulatory documents do not adequately address the specific features of layered additively manufactured elements, which significantly complicates their structural analysis and practical implementation. This paper presents the results of experimental testing of shallow tied-arch structures manufactured using a construction 3D printer developed by the Ukrainian company UTU. The arches were produced using a layered printing process and subsequently subjected to controlled experimental loading. The testing methodology proposed and implemented by the authors is described in detail, including the loading scheme, boundary conditions, and measurement of structural response. Experimental investigations were carried out under the action of concentrated loads applied at the third points of the span, which allowed the assessment of the structural performance of the arches under realistic loading conditions. The obtained results provide valuable insights into the load-bearing behavior and deformation characteristics of 3D-printed shallow arch structures with ties and contribute to the formation of a reliable experimental basis for further analytical and numerical studies. These findings may serve as a foundation for the development of design recommendations and future regulatory approaches for additively manufactured structural systems.

M. EL Afandi, S. Yehia, T. Landolsi et al.

A. El-Abbasy

Marina Tenório, Rui Ferreira, Victor Belafonte et al.

Modular timber construction embodies a pioneering and eco-friendly methodology within the building sector. With the notable progress made in manufacturing technologies and the advent of engineered wood products, timber has evolved into a promising substitute for conventional materials such as concrete, masonry, and steel. Beyond its structural attributes, timber brings environmental advantages, including its inherent capacity for carbon sequestration and a reduced carbon footprint compared to conventional materials. Timber’s lightweight nature, coupled with its versatility and efficiency in factory-based production, accelerates modular construction processes, providing a sustainable solution to the growing demands of the building industry. This work thoroughly explores contemporary modular construction using wood as the primary material. The investigation spans various aspects, from the fundamentals of modularity and the classification of modular timber solutions to considerations of layout design, structural systems, and stability at both the building and module levels. Moreover, inter-module joining techniques, MEP (mechanical, electrical, and plumbing) integration, and designs for disassembly are scrutinized. The investigation led to the conclusion that timber modular construction, drawing inspiration from the steel modular concept, consistently utilizes a structural approach based on linear members (timber frame, post-and-beam, etc.), incorporating stability configurations and diverse joint techniques. Despite the emphasis on modularization and prefabrication for adaptability, a significant portion of solutions still concentrate on the on-site linear assembly process of those linear members. Regarding modularity trends, the initial prevalence of 2D and 3D systems has given way to a recent surge in the utilization of post-and-beam structures, congruent with the ascending verticality of buildings. In contrast to avant-garde and bold trends, timber structures typically manifest as rectilinear, symmetric plans, characterized by regular and repetitive extrusions, demonstrating a proclivity for centrally located cores. This work aims to offer valuable insights into the current utilization of modular timber construction while identifying pivotal gaps for exploration. The delineation of these unexplored areas seeks to enable the advancement of modular timber projects and systems, fully leveraging the benefits provided by prefabrication and modularity.

Siyu Wu, Sukhoon Pyo

Abstract Some studies have developed different kinds of vibration-reducible construction materials. However, no existing study has applied these materials in a building to prove their effectiveness at a structural level. Besides, much of the related research has focused only on measuring sound pressure or vibration levels within buildings adjacent to railway systems. Although some studies have provided methods to predict the vibration of a building structure, they cannot determine the train-induced sound pressure level simultaneously. Therefore, this study used the finite element model to simulate an existing building structure to prove the effectiveness of this method. Based on the combination of the acoustic and solid interaction modules in the finite element analysis method, the vibration and sound levels of buildings based on different kinds of vibration-reducible cementitious materials were estimated using different models. The results show that vibration-reducible cementitious materials can reduce vibration velocity and sound pressure levels by up to 7.1 dB and 5.2 dB with an increased floor height, respectively. In addition, reduced vibration can decrease structure-borne noise by up to 2.9 dB. A further parametric study shows that cementitious materials with a relatively high elastic modulus, a high damping loss factor, and low density can be effective for vibration and sound reduction.

Ahmad G. Saad, Mohammed A. Sakr, Tarek M. Khalifa et al.

Abstract The integration of web openings in reinforced concrete (RC) beams significantly reduces their shear capacity and impact resistance. This research uniquely investigates the full-scale flexural and shear behavior of un-designed RC beams with web openings subjected to low-velocity impact loading (14715 J). The study systematically varies opening location (midspan versus shear zone) and aspect ratio (width: 0.75h, 1.0h, 1.5h, and 2.0h, depth: 0.2h, 0.3h, 0.4h; h = beam height) while maintaining a constant opening area. The effectiveness of externally bonded carbon fiber-reinforced polymer (CFRP) reinforcement in mitigating the detrimental effects of these openings is numerically investigated. Novel findings indicate that RC beams with smaller openings in the shear zones do not necessitate further strengthening, whereas larger shear-zone openings benefit considerably from CFRP, reducing peak deflections up to 8.9% using one CFRP layer. For beams with one midspan opening, positioning the opening optimally within the tension zone above the tensile reinforcement is shown to maximize the top chord's effective depth, thereby enhancing CFRP's impact resistance effectiveness, with peak deflection reductions of up to 26.18%. This study demonstrates that top chord CFRP reinforcement effectively prevents localized failure and enhances load transfer in RC beams with midspan openings under dynamic loading, offering improved retrofitting solutions for impact resistance.

Lindong Li, Zilin Wang, Sihong He et al.

Abstract To improve the corrosion resistance of steel fibers under chloride ion attack in coastal environments and enhance the interfacial bonding between steel fibers and concrete, this study utilized an optimized concentration of γ-aminopropyltriethoxysilane (KH550) solution. Through a hydrolysis–condensation reaction, a silane modification protective film was formed on the surface of the steel fibers, leading to the development of a novel anti-corrosive steel fiber reinforced concrete. Semi-cylindrical specimens of both silane-modified and ordinary steel fiber reinforced concrete were prepared. After subjecting these specimens to dry–wet cycles in a chloride salt environment, they were mechanically loaded using a UTM testing machine, and the loading process was monitored using the XTDIC digital speckle technique. Microstructural characterization confirmed that KH550, via hydrolysis–condensation reactions, effectively generated a modification film on the surface of the steel fibers that prevented chloride ions from penetrating and reduced chloride-induced corrosion. Mechanical tests show that the peak load of the modified specimens increased by 4.24%, and the time required for destruction in the stress concentration stage, crack initiation stage, and macro-crack development stage was prolonged and the strain rate was reduced, proving that the interface bonding ability was enhanced. Overall, this technology achieves a synergistic optimization of durability and mechanical performance through an interfacial reinforcement strategy, providing a new approach for protecting coastal engineering structures against chloride-induced corrosion.

Sangwoo Kim, Yujeong Lee, Jinsup Kim et al.

Abstract Research on concrete durability during prolonged use has been ongoing due to concrete’s widespread use in construction. Freeze–thaw cycles exert a significant impact on concrete durability, especially in regions with harsh climates. While existing studies primarily focus on material aspects, research on the performance degradation of reinforced concrete (RC) structures is limited. This limitation is attributed to the inadequacy of current freeze–thaw testing standards for large structures like RC structures. Therefore, there is a need to propose freeze–thaw testing methods tailored for RC members. This study investigates the influence of air content and freeze–thaw cycles on the material and structural properties of RC beams, proposing a novel rapid freeze–thaw testing method for RC members. The study compares this new method (N test) with the conventional ASTM C666/C666M-15 rapid freeze–thaw testing procedure (A test), aiming to establish a correlation between the two experiments. Concrete mixtures with air content ranging from 0 to 9% underwent two types of freeze–thaw tests, followed by flexural testing of RC beams. The results were analyzed for air content, slump, compressive strength, mass loss, crack patterns, and failure modes, and they offer insights into the relationship between air entrainment, freeze–thaw resistance, and the structural behavior of RC under diverse environmental conditions.

Engy Hany, Nabil Fouad, Mona Abdel-Wahab et al.

Abstract The production of conventional bricks has negative impact on the environment due to CO2 emissions. Therefore, the use of alkali-activated by-product materials as partial or full replacement of cement has been promising in producing eco-friendly compressed earth bricks for sustainable construction. This research aims to simulate the thermal behavior of an office building prototype composed of eco-friendly compressed earth brick (CEB) walls using Design Builder software to investigate the impact of CEB walls on the indoor thermal comfort, total energy consumption and CO2 emissions. In addition to investigate the influence of the type and thicknesses of walls, and thickness of expanded polystyrene (EPS) insulating layer on the total energy consumption and (CO2) emissions. The results indicated that using walls of compressed earth bricks (CEB) made by alkali-activated ground granulated blast furnace slag (GGBS) as soil stabilizer with full replacement of cement is promising for reducing the total energy consumption and CO2 emissions with competitive compressive strength to those stabilized by cement. The results also revealed the noticeable effect of the type and thicknesses of walls in addition to the thickness of EPS insulating layer in reducing the total energy consumption and CO2 emissions. This reduction reached about 21–25% for different wall types of thickness 120 mm when EPS thicknesses increased up to 50 mm compared to the same walls without EPS.

Irina F. Zenkova, Evgeniy V. Kozyrev, Oleg N. Lutsenko

The article sets out the main directions of the All-Russian Scientific and Practical Conference «Security of the Russian Arctic: Historical, Geopolitical, Environmental, Technical and Economic Aspects» - the first event of exercise business program “ Safe Arctic – 2025”. There are presented the fundamental normative legal acts of the Russian Federation defining the strategy for the development of the Arctic zone of the Russian Federation, ensuring national security and defining the goals, main directions and objectives of state policy in the Arctic. There are listed the inputs, the realisation of which is determined by the exercise. A conclusion was drawn on the need to apply interdisciplinary approaches in the development of the Arctic region and to ensure its security in the context of modern geopolitical challenges.

Changguang Dong, Qiujie Qiao

In [52], Parmenter and Pollicott establish an abstract criterion that gives a geometric construction of equilibrium states for a class of partially hyperbolic systems. We refine their criterion to cover a much broader class of diffeomorphisms, which include certain diffeomorphisms with exponential mixing property (with respect to volume), Katok maps and ``almost Anosov'' diffeomorphisms. As a special case, we obtain a construction of equilibrium states for ergodic partially hyperbolic affine maps/flows on homogeneous spaces, without any restrictions on the orbit growth along center directions.

S. R. Chowdhury, D. Ahmed, A. Asiz et al.

The study investigates and compares six different types of ten-story residential buildings, focusing on structural design, performance, and carbon emissions. Three buildings include slab and shear wall components, while the other three comprise structural frames, each designed differently with Cross Laminated Timber (CLT), Reinforced Concrete (RC), and hybrid systems. Through modeling in ETABS and adherence to Saudi Building Code (SBC), all buildings met strength and serviceability criteria. Notably, the CLT-based buildings displayed varied deflection characteristics compared to RC-based structures. Moreover, carbon emissions were assessed from manufacturing to construction stages, considering CLT and RC elements. The data, including material volumes and weights, were essential for emission calculations. Results indicated varying CO2 production levels based on specific materials used in construction. Additionally, the study involved a survey among construction companies to gather feedback on CLT utilization, aiming to further analyze industry perspectives. This comprehensive analysis sheds light on the structural and environmental aspects of diverse building types, offering an understanding of their performance and carbon footprint.

Huiying Wang

Porous structures are widely utilized across various fields, including biomedical engineering, environmental remediation, energy storage devices, and construction and building materials, owing to their lightweight nature, high surface areas, exceptional sound and energy absorption capacities, as well as their thermal insulation properties and customizable designs. Practical applications of porous structures encompass tissue scaffolds, air and water filtration systems, fuel cells, lightweight concrete, and acoustic panels. Investigating the free vibration behavior of porous structures is essential, as unfavorable behavior can jeopardize structural safety and serviceability. Therefore, this study examines the stochastic free vibration performance of porous structures, considering relatively high-dimensional uncertainties with disparate distributions. A deep learning strategy, i.e., the cutting-edge Gated Additive Tree Ensemble, is incorporated to delineate the complex relationship between various uncertainties and the vibration characteristics of porous structures. Extensive statistical information on structural behavior, involving the mean, standard deviation, coefficient of variation, probability density function, and cumulative distribution function, is offered to facilitate structural safety assessments and reliability-based material optimization. Moreover, numerical studies demonstrate quantitatively the advantages of the presented deep learning technique over existing surrogates in terms of estimating efficiency and accuracy.

A. Rasyefki, Mahmoud Syiraj

Three-dimensional (3D) printing technology, also known as Additive Manufacturing (AM), has rapidly advanced in the construction industry and is increasingly applied across different scales, ranging from small components to full-scale building projects. This article reviews the evolution of 3D printing technology with a particular focus on printing systems (gantry, robotic arms, and mobile systems), materials employed (concrete, polymers, and metals), and its applications in various construction projects. Findings indicate that 3D printing offers significant advantages in terms of time efficiency, cost reduction, and sustainability through material optimization and waste minimization. Nevertheless, several challenges remain, including regulations, quality standards, and long-term material durability. With the integration of intelligent technologies and continuous research, 3D printing holds the potential to emerge as a new paradigm in global construction practices.

Avishreshth Singh, Prasanna Venkatesh Sampath, Krishna Prapoorna Biligiri

Meysam Alizamir, A. Gholampour, Sungwon Kim et al.

Precisely forecasting how concrete reinforced with fiber-reinforced polymers (FRP) responds under compression is essential for fine-tuning structural designs, ensuring constructions fulfill safety criteria, avoiding overdesigning, and consequently minimizing material expenses and environmental impact. Therefore, this study explores the viability of gradient boosting regression tree (GBRT), random forest (RF), artificial neural network-multilayer perceptron (ANNMLP) and artificial neural network-radial basis function (ANNRBF) in predicting the compressive behavior of fiber-reinforced polymer (FRP)-confined concrete at ultimate. The accuracy of the proposed machine learning approaches was evaluated by comparing them with several empirical models concerning three different measures, including root mean square errors (RMSE), mean absolute errors (MAE), and determination coefficient (R2). In this study, the evaluations were conducted using a substantial collection of axial compression test data involving 765 circular specimens of FRP-confined concrete assembled from published sources. The results indicate that the proposed GBRT algorithm considerably enhances the performance of machine learning models and empirical approaches for predicting strength ratio of confinement (f′cc/f′co) by an average improvement in RMSE as 17.3%, 0.65%, 66.81%, 46.12%, 46.31%, 46.87% and 69.94% compared to RF, ANNMLP, ANNRBF, and four applied empirical models, respectively. It is also found that the proposed ANNMLP algorithm exhibits notable superiority compared to other models in terms of reducing RMSE values as 9.67%, 11.29%, 75.11%, 68.83%, 73.64%, 69.49% and 83.74% compared to GBRT, RF, ANNRBF and four applied empirical models for predicting strain ratio of confinement (εcc/εco), respectively. The superior performance of the GBRT and ANNMLP compared to other methods in predicting the strength and strain ratio confinements is important in evaluating structural integrity, guaranteeing secure functionality, and streamlining engineering plans for effective utilization of FRP confinement in building projects.